Nutrition 30 (2014) 49–54
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Applied nutritional investigation
Medical weight loss versus bariatric surgery: Does method affect body composition and weight maintenance after 15% reduction in body weight? Michelle G. Kulovitz Ph.D. a, *, Deborah Kolkmeyer M.S. b, Carole A. Conn Ph.D. a, Deborah A. Cohen D.C.N. a, Robert T. Ferraro M.D. b a b
Department of Individual, Family, and Community Education, University of New Mexico, Albuquerque, New Mexico, USA Southwest Endocrinology Associates, Albuquerque, New Mexico, USA
a r t i c l e i n f o
a b s t r a c t
Article history: Received 15 January 2013 Accepted 11 June 2013
Objective: The aim of this study was to investigate body composition changes in fat mass (FM) to lean body mass (LBM) ratios following 15% body weight loss (WL) in both integrated medical treatment and bariatric surgery groups. Methods: Obese patients (body mass index [BMI] 46.6 6.5 kg/m2) who underwent laparoscopic gastric bypass surgery (BS), were matched with 24 patients undergoing integrated medical and behavioral treatment (MT). The BS and MT groups were evaluated for body weight, BMI, body composition, and waist circumference (WC) at baseline and after 15% WL. Results: Following 15% body WL, there were significant decreases in %FM and increased %LBM (P < 0.0001). Additionally, both groups saw 76% of WL from FM, and 24% from LBM indicating a 3:1 ratio of FM to LBM loss during the first 15% reduction in body weight. Finally, no significant differences (P ¼ 0.103) between groups for maintenance of WL at 1 y were found. For both groups, baseline FM was found to be negatively correlated with percentage of weight regained (%WR) at 1 y post-WL (r ¼ 0.457; P ¼ 0.007). Baseline WC and rate of WL to 15% were significant predictors of %WR only in the BS group (r ¼ 0.713; P ¼ 0.020). Conclusion: If followed closely by professionals during the first 15% body WL, patients losing 15% weight by either medical or surgical treatments can attain similar FM:LBM loss ratios and can maintain WL for 1 y. Ó 2014 Elsevier Inc. All rights reserved.
Keywords: Bariatric surgery Weight loss Body composition Obesity Weight maintenance Lean mass Fat mass
Introduction With obesity rates and corresponding health risks rising each year, health professionals have been dedicated to understanding the physiological mechanisms of weight loss (WL), as well as the ability to keep their patients’ weight stable following significant WL [1]. According to the National Heart, Lung, and Blood Institute’s (NHLBI) current guidelines for clinicians, successful WL for obese individuals is defined as a 10% reduction in initial MGK was responsible for design and concept of project, imputing data collected, writing manuscript, creating figures, interpretation of data, and statistical analysis of data. CAC was responsible for design and concept of project, interpretation of data, editing and writing of manuscript. DA was responsible for design and concept of project, data collection, and editing and writing manuscript. DC was responsible for editing and writing manuscript as well as interpretation of data. RTF was responsible for editing manuscript. * Corresponding author. Tel.: þ1 505 277 2658; fax: þ1 505 277 6227. E-mail address: [email protected] (M. G. Kulovitz). 0899-9007/$ - see front matter Ó 2014 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.nut.2013.06.008
body weight that is maintained for at least 1 y [1–4]. Current research has stated that maintaining WL for >1 y using integrated medical treatment or bariatric surgery (BS) is largely predicted by a high baseline fat mass (FM), in conjunction with other metabolic factors, that favor the preservation of lean body mass (LBM) as percentage of body weight (%LBM) [5–11]. Understanding the differences between therapeutic approaches to losing excess weight for obese individuals is important to determine if there are differences in predictors of sustained WL. Currently, limited research exists comparing WL approaches through the use of integrated medical and behavioral treatment (MT) and the use of laparoscopic gastric bypass BS. The use of BS increased nearly sixfold between 1990 and 2000 in the United States, averaging from 2.4 to 14.1 per 100,000 adults [4]. Currently, BS serves as one of the fastest and most effective WL techniques for severely obese individuals that can maintain a significant loss of weight over time [3,5]. Existing research has found that gastric bypass BS patients can lose an
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average of 11.8% and 28.5% of initial body weight, with a %LBM loss of 9.4% and 20.3% in 30 d and 180 d, respectively [5]. WL with BS patients has been shown to alter body composition dramatically and unfavorably by decreasing both FM and LBM at the same rate [12]. Results of a 2000 study were similar to those obtained in a later study that compared laparoscopic gastric bypass BS to MT [6,12]. BS patients showed a 10% WL with equal amounts of %LBM and %FM loss at 6 wk, whereas MT resulted in a 10% WL at 30 wk with an increase of 5.2% in %LBM [6]. Due to the rapid WL seen with BS, there is a need to further understand the effect BS and rate of weight loss (RWL) has on body composition when compared with MT [4,5]. Past research has only focused on the anthropometric marker of 10% of initial body weight reduction as defined by the NHLBI, yet BS surgery and MT patients may experience WL in excess of this. Past research has indicated that some metabolic markers and nutritional status changes do occur after a 10% decrease in initial body weight, however, the 15% marker has yet to be investigated [6]. To our knowledge, it is not known if losing more than the NHLBI guidelines of 10% initial body weight, provides the same reductions in %FM and %LBM for both BS and MT patients and permits successful maintenance of WL over 1 y or more. The key objective of this study was to determine if using either MT or BS to induce WL to 15% initial body weight will alter the final ratio of FM:LBM. Additionally, this study investigated influences of treatment on weight maintenance after 1 y of 15% WL. Additionally, there is no known research comparing RWL to 15% between BS and MT patients. The understanding of the ratio between FM:LBM loss for both BS and MT patients will help clinicians better understand what to expect when patients lose 15% of initial body weight or more and what can help predict WL maintenance over time using either treatment. Methods Participant selection The data included in this study are part of a continuous collection by the Southwest Endocrinology Associates Weight Management Center (SWENDO) from January 2010 to January 2012 where at least 400 active patients in Albuquerque, New Mexico are currently enlisted. SWENDO’s comprehensive program includes a medical team of physicians, physician assistants, registered dietitians, exercise physiologists/personal trainers, nurse/medical assistants, and mentors all trained to perform analysis of patients. Participants were included in the study if they reached a 15% reduction in initial body weight while under the care of SWENDO; they were in medically supervised WL program at SWENDO only or had laparoscopic gastric bypass BS while under the care of SWENDO; their medical charts contained all data needed including dates of measurements, age, sex, body weight, height, waist circumference (WC), and body composition analysis; and they were actively enrolled in SWENDO weight management program during the 15% WL period. All participants gave written consent for all treatment data to be used for research purposes and this study was granted approval for use by the University of New Mexico Institutional Review Board.
Participant demographics The study population (N ¼ 48) included both men (n ¼ 6) and women (n ¼ 42), ages ranging from 26 to 68 y with a mean age of 50.4 9.9 y, of various ethnicities who reside in the state of New Mexico, and are under the care of SWENDO weight management program. Participant data were split into two groups: BS group (n ¼ 24) and MT group (n ¼ 24). Both groups were similar for baseline age at initial WL, sex, and initial body mass index (BMI) with no significant differences as shown in Table 1. Measurements included in the study were taken at baseline before WL, after approximately 15% body WL, and at 1 y following achievement of 15% loss, if available. Due to study duration, some patients did not reach 1-y post 15% WL simply because of the dates established to frame the duration of the analysis period. This did cause limited 1-y follow-up
Table 1 Characteristics of participants
Number of participants Age (y) Weight (kg) Initial BMI (kg/m2) FM (kg) LBM (kg) Days to 15% WL Initial %BF %WL
Medical treatment (N ¼ 24)
Bariatric surgery (N ¼ 24)
(F ¼ 21; M ¼ 3) 50.1 10.0 120.6 20.3 45.28 6.3 59.0 11.4 61.6 13.7 295.2 347.9 50.5 5.5 17.0 3.1
(F ¼ 21; M ¼ 3) 50.7 10.1 126.6 20.9 46.6 6.5 63.8 13.1 62.8 12.6 151.2 85.5 50.3 5.4 18.3 2.8
BMI, body mass index; %BF, percent body fat; LBM, lean body mass; FM, fat mass; %WL, percent weight loss
data. Percent weight regain (%WR) is defined as the change in weight, either positive or negative, from the 15% WL marker. Medically supervised treatment group Participants included in the MT group underwent highly individualized treatment programs with professional guidance while under the care of SWENDO. Supervised medical individualized treatment options determined by the participant and SWENDO professionals included some or all of the following: group support classes, individualized coaching/counseling sessions, and full dietary meal planning. All MT patients were recommended a calorie-deficit diet to target 500 to 2000 kcal/d and achieve no more than an average of a 1% reduction in body weight weekly. Food plans are negotiated with each individual based on their personal needs, however, on average, MT patients consumed between 45% and 65% of total calories from carbohydrates, 25% and 35% of total calories from protein, and between 20% and 35% of total calories from fat. All MT patients kept food journals and were monitored by SWENDO professionals. This macronutrient breakdown follows the guidelines provided by the Institute of Medicine (IOM) and the 2010 Dietary Guidelines for Americans, however, tended to be on the higher composition for protein (80–100 g/d), lower composition of fat, and moderate intake of carbohydrates [13,14]. MT patients also could have used partial and/or full Optifast Ò meal replacements and/or pharmacologic WL agents (phentermine and diethyproprion). Meal replacements and/or portion-controlled meals were strongly encouraged at least as part of the patient’s diet. The uses of medications were introduced as needed and often used intermittently. It could be estimated that at any point in time, about 25% of the total active clients enrolled in a SWENDO program are in possession of a current prescription for either diethylproprion (25 mg one to three times daily) or phentermine 37.5 mg (one-half to one tablet daily). Patients who participated in the program could choose their personal methods of WL with support from the SWENDO medical team. Laparoscopic roux-en-Y gastric bypass bariatric surgery group Similar to participants in the MT group, those included in the BS group also were members of the SWENDO comprehensive program where they had access to the same weekly group support classes and education, individualized coaching/counseling sessions, and individualized dietary meal planning. Before and after laparoscopic Roux-en-Y gastric bypass surgery, patients were educated on their specific diet post-surgery. The early postoperative nutritional plan was very regimented and included a soft diet of mostly protein and one or more protein shakes (totaling 80–100 g of protein) daily. Total daily calorie intake remains at 0.05), initial FM (63.8 13.1 kg versus 59.0 0.4 kg; P > 0.05), and initial LBM (62.8 12.6 kg versus 61.6 13.7 kg; P > 0.05) (Table 1). Following approximately 15% body WL both the BS group and the MT group had similar reductions in body weight with no significant differences, 23.4 6.2 kg versus 20.8 5.3 kg; P > 0.05 (8.5 1.9 kg/m2 versus 7.8 1.9 kg/m2; P > 0.05). Additionally, both groups were found to have significant changes in distribution of %FM and %LBM within groups. In the BS group %FM decreased (50.3% 5.4% to 44.3% 6.7%; P < 0.0001), whereas %LBM increased (49.7% 5.4% to 55.7% 6.7%; P < 0.0001), and in the MT group %FM decreased (49.0% 5.5% to 43.3% 5.7%; P < 0.0001), whereas %LBM increased (51.0 5.5 to 56.7 5.7%; P < 0.0001). Contrary to previous research findings, these body composition results were similar and not significantly different (P > 0.05) between the BS and the MT groups as reported in Table 2 [6]. Additionally, no significant differences in FM and LBM reductions between groups were found [6]. Following 15% WL for both the BS and MT groups saw approximately 76% of WL from FM, and 24% from LBM indicating an approximate 3:1 ratio of FM to LBM loss [6]. As stated in Table 2, both groups saw significant losses from baseline in the FM:LBM ratio, whereas there was no statistically significant differences between the final FM:LBM ratios for the MT and BS groups. To investigate predictors of weight maintenance at 1 y, simple and multiple regression analysis were conducted. There were no significant differences (P ¼ 0.103) between groups for weight maintenance, where weight maintenance at 1 y was expressed as a %WR 1 y following the achievement of approximately 15% weight loss. For combined groups (n ¼ 34) baseline FM was
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Weight (kg) BMI (kg/m2) WC (cm) %BF LBM (kg) LBM (%) FM (kg) FM (%) FM:LBM
Medical treatment
Bariatric surgery
Before
After
Before
100 17.2* 37.5 5.2* 110.5 10.6* 43.3 5.7* 56.7 12.1* 56.7 5.7* 43.3 9.7* 43.3 5.7* 0.8 0.2*
126.6 46.6 131.2 50.3 62.8 49.7 63.8 50.3 1.03
120.6 45.28 123.7 50.5 61.6 51.0 59.0 49.0 1.06
20.3 6.3 12.7 5.5 13.8 5.5 11.4 5.5 0.21
20.9 6.5 4.2 5.4 12.6 5.4 13.1 5.4 0.209
After 103.3 16.3* 38.1 5.3* 116.1 4.0* 44.3 6.7* 57.3 11.0* 55.7 6.7* 46.0 11.1* 44.3 6.7* 0.8 0.2*
WL, weight loss; BMI, body mass index; WC, waist circumference; %BF, percent body fat; LBM, lean body mass; FM, fat mass; FM:LBM, ratio of fat mass to lean body mass * P < 0.05 vs. baseline.
found to be significant and negatively correlated with %WR at 1 y post-WL (r ¼ –0.457; P ¼ 0.007) as shown in Figure 1. All patients with data at 1 y following 15% WL, were able to keep most of the weight lost at 1 y, however, the BS group tended to continue to lose weight at 1 y compared with the MT group (not significantly different) (Fig. 2). When differentiating predictors between groups, multiple regression analysis showed that the combination of baseline WC and RWL are a significant predictor of %WR only in the BS group (r ¼ 0.713; P ¼ 0.020). No predictors for %WR were statistically significant for the MT group. Other variables at baseline (age, LBM, %LBM, %FM, %BF) did not contribute to the change in %WR at 1 y in either group. Due to a limited study duration where some patients had yet to reach 1 y post-15%WL, there was limited 1-y follow-up data. Only 15 BS and 19 MT patients contained data to 1 y post-WL and were included in the regression analysis and weight maintenance trend (Figs. 1 and 2, respectively). Discussion According to the NHLBI, there are several known effective WL treatments that exist for obesity management that include integrated medical, behavioral, and surgical treatments. Published studies have found variable results with regards to body composition changes that occur following these treatments [1]. Additionally, there are several therapeutic strategies currently being investigated as potential treatments to aid in body WL or optimize body composition ratios during WL; however, more
Fig. 1. Percent body weight regain from 15% WL as a function of FM at baseline in a subset of both MT (n ¼ 19) and BS (n ¼ 15) patients who had 1-y follow-up data available for analysis (r ¼ 0.457; P < 0.05).
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Fig. 2. Available participant data for average weight (kg) in both the BS (n ¼ 15) and MT (n ¼ 19) groups that had available data at 1 y post-15% WL. Body weights at baseline, 15% weight loss, and at 1 y following 15% weight loss were included. No significant differences were found between groups (P > 0.05).
research is needed to investigate WL to 15% initial body WL [18, 19]. In this study, both the BS and MT groups lost approximately 15% of their initial body weight due to negative energy balance. Because both groups were supervised during their WL period by the SWENDO weight management center, care for both groups was similar and consistent. Given that both groups were provided with individualized diet therapy that was tailored to their individual needs, we hypothesize that ensuring adequate protein intake to preserve LBM was vital. Dietary protein intake following massive body WL > 10%, is considered necessary to preserve LBM, nutritional status, and satiety during WL [3,6,20, 21]. Additionally, high-protein intake following body WL has been shown to contribute to a 50% lower body weight regain than consumption of a higher-carbohydrate and lower-protein diet [21]. Maintaining LBM is a concern with any population where large decreases in body weight occur in a short period of time [2, 3,5,6,9]. It appears that use the BIA as a measurement of change in body composition in obese undergoing WL has been accepted in the literature [22]. According to one study (1999), obese individuals (BMI 25–65 kg/m2) undergoing WL were assessed using both hydrostatic weighing, the current gold standard for assessing body composition, and BIA [22]. No significant differences were found in assessing FM changes in the study population. Similarly, BIA was validated against deuterium oxide dilution (D2O) using hydrometry [23]. No significant differences were found when patients adhered to pretest guidelines for BIA as did our study population. A 2011 study questioned the reliability of BIA in morbidly obese patients (BMI 36.2–45.4 kg/m2) undergoing bariatric surgery and rapid WL [24]. The study found that BIA limitations in terms of body water and FM were more relevant for males than females. The BIA was found to be valid and reliable in female patients. Because our study population was 48 women versus 6 men, we believe this could contribute to a marginal amount of error. Furthermore, previous studies have reported that BIA can overestimate FM and underestimated FM compared to dual-energy X-ray absorptiometry (DXA) [25], whereas DXA is known to underestimate LBM and overestimate FM in obese individuals when compared with the four-compartment model [26]. If the assumptions of the BIA are true, because the present study is only addressing the change in FM:LBM ratio, it is assumed that all participants will have overestimated LBM and underestimated FM equally between groups. Thus, the ratio between FM:LBM is not affected. No significant differences between groups were found in losses of absolute FM and LBM, as well as %FM and %LBM. WL of both
the BS and MT groups to 15% saw 76% of WL from FM, and 24% from LBM in 151.2 85.5 d versus 295.2 347.9 d, respectively. These results suggest that the first 15% of body WL could have a 3:1 ratio of FM:LBM loss in both BS and MT populations when cared for by weight management professionals. The results of the BS group were consistent with a previous study in which a 3:1 ratio of FM:LBM loss was seen after 6 mo (182 d) and also after 1 y. Additionally, similar results were seen in a 3:1 ratio of FM:LBM loss in the MT group in a study that compared MT with BS patients to 10% WL [6,27]. Contrary to our results, body WL in that study’s BS patients saw a 1:1 ratio of FM:LBM loss where exercise was not discussed as an emphasis in their BS group [6]. Additionally, our results are supported by research done in an earlier study that found that implementation of resistance training along with a hypocaloric diet during WL can preserve more LBM [28]. Results of this current study may imply that from baseline to a 15% reduction in body weight until approximately 1 y of WL, the ratio of FM:LBM is 3:1 with supervised care. Furthermore, for patients undergoing BS under the care of weight management professionals where individualized diet and exercise prescriptions are used, surgery can yield similar results in distribution of body composition and preservation of LBM as an intensive lifestyle intervention. As displayed in Table 2, results of this study indicate that both the BS and the MT groups decreased their %FM and increased their %LBM. This finding was different from previous research comparing MT with BS patients. Previous researchers saw a significant decrease in %FM and increase in %LBM in the MT group only, however, the BS group remained unchanged in %FM and %LBM [6]. Similar results were found in a study that observed RWL in BS patients only, where a 1:1 ratio of %FM to % LBM loss was reported in this population [12]. The similar RWL seen in both groups with a concurrent increase in %LBM could be attributed to the higher protein diet of 80 to 100 g/d in combination with a hypocaloric-individualized diet. Current research assessing 80 g protein for women and 100 g protein for men on LBM preservation after BS revealed that higher protein intakes resulted in less weight regain after 2 y postsurgery [19]. Whether the WL approach is through the use of integrated MT or the use of laparoscopic gastric bypass BS, the integration of adequate protein in the diet and incorporation of physical activity to preserve LBM is of utmost importance [1,3,4, 8,9,12]. Although current practice may suggest a higher protein need to preserve LBM, the current guidelines from the American Association of Clinical Endocrinologists (AACE) specific for nutrition support of BS patients who have undergone gastric bypass recommend an intake of protein 60 g/d [6,19,29,30]. The protein intake recommended to BS patients at SWENDO is currently greater than the recommended intake of 60 g/d recommended by the AACE and may have contributed to the greater preservation of LBM in the present study. This study found no significant differences between RWL to 15% using BS or MT techniques, however, it may be clinically significant that mean RWL between groups was almost double in BS (151.2 85.5 d versus 295.2 347.9 d, respectively). The nonsignificant differences seen in RWL between groups is in contrast to previous findings by others where MT groups saw an average WL to 10% at 182 d and BS patients at 42 d [6]. Large standard deviations were seen with the RWL variable in the MT group indicating fluctuating WL and weight regain before reaching a 15% WL goal in the MT group. Weight maintenance 1 y following a 15% reduction in body weight was similar between groups with no significant differences (Fig. 2). Whereas many studies have shown weight
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regain following significant weight loss, the individualized care received from the SWENDO team, weight regain was negative (i.e., continued loss) after 1 y. This finding can imply that no matter whether the method of WL is BS or MT, the WL can be maintained in clinically supervised patients [3,9,31]. Of the individuals monitored for 1 y post-15% WL, all individuals in the BS group were able to maintain or continue to lose weight after 1 y. Although still below their baseline weight, two individuals in the MT group gained weight from their body weight measured at 15% WL (Fig. 1). Both groups were combined to determine a common predictor of %WR at 1 y. Baseline FM was a significant predictor for both groups to determine %WR following 15% WL (Fig. 1). Regardless of group, individuals with higher baseline FM regained less or lost more weight after 1 y. This result is consistent with previous research studying both BS and MT populations [9–11]. This outcome can be explained because obese individuals have higher %BF indicating an unhealthy body composition [17,24]. In order to reach a healthier FM:LBM ratio, obese individuals typically lose mostly FM quicker than leaner individuals in a shorter period of time when a hypocaloric diet with adequate protein and exercise are used [9]. Analysis between groups indicated that the combination of baseline WC and RWL was a significant predictor of %WR at 1 y in the BS group only (r ¼ 0.713; P ¼ 0.020). When these predictors are taken together, the results suggest that the BS patients losing weight at a slower rate and having a larger WC at baseline tend to lose more weight over the course of 1 y following 15% WL. It can be argued that a larger WC could indicate more abdominal fat, perhaps indicating increased baseline FM. Similar findings were found in a study that showed gradual and sustained WL following surgery in patients who underwent laparoscopic adjustable gastric banding [32]. Furthermore, recent WL studies investigating hormonal influences before and 12 mo after Roux-en-Y gastric bypass surgery in adults (i.e., serum-ghrelin) [33] or after an intensive lifestyle intervention in children (i.e., leptin and adiponectin) [34], have shown that hormonal influences may have a predictive value in WL; however, these are still not fully understood. Because weight maintenance after WL is a multifactorial issue in patients and is a combined effect of baseline body composition, and many other mechanisms still not fully understood, these results are limited to this clinical study population only [3,9,35,36]. Our study has limitations common to small retrospective studies. Our population included free-living men and women that were pre- or postmenopausal and were of different age categories. One-y weight follow-up data was limited within the participants studied due to time limitations for data analysis. Some patients had yet to reach 1 y following attainment of 15% WL. Additionally, participants were self-selected into treatments so they could not be randomized. Large SDs were found with MT patients who had weight fluctuations throughout the 15% WL period. More research is needed with a larger sample size to study 15% WL comparing both populations. Although we speculate that the higher-protein recommendation and/or individualized exercise prescriptions contribute to the beneficial 3:1 ratio of FM:LBM loss in both MT and BS patients, future studies should measure actual intake and exercise levels to test these hypotheses. The novelty of the present study also could be seen as a limitation. Because study participants were free-living patients with direct influences on treatment, dietary and physical activity recommendations were individualized to each patient and not standardized. We believe that this does provide an opportunity to further the literature in free-living clinical populations where individualized treatment is prescribed. Due to the retrospective
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nature of this study, future research is necessary to provide evidence that these outcomes may occur in a study population with a controlled experimental design. Conclusion The findings of this study strengthen the efficacy of WL to 15% initial body weight for both medical and surgical treatments for obesity. If followed closely by well-qualified medical teams during the first 15% of initial body weight loss, patients losing weight using either treatment can be successful in maintaining similar FM:LBM ratios during weight loss and are able to keep the weight off for at least 1 y. References [1] National Heart Lung and Blood Institute. Clinical Guidelines on the Identification, Evaluation, and Treatment of Overweight and Obesity in AdultsdThe Evidence Report. National Institutes of Health. Obes Res 1998;6(Suppl 2):51S–209S. [2] Nackers LM, Ross KM, Perri MG. The association between rate of initial weight loss and long-term success in obesity treatment: does slow and steady win the race? Int J Behav Med 2010;17:161–7. [3] Wing RR, Hill JO. Successful weight loss maintenance. Annu Rev Nutr 2001;21:323–41. [4] Trus TL, Pope GD, Finlayson SR. National trends in utilization and outcomes of bariatric surgery. Surg Endosc 2005;19:616–20. [5] de Aquino LA, Pereira SE, de Souza Silva J, Sobrinho CJ, Ramalho A. Bariatric surgery: impact on body composition after Roux-en-Y gastric bypass. Obes Surg 2012;22:195–200. [6] del Genio F, Alfonsi L, Marra M, Finelli C, del Genio G, Rossetti G, et al. Metabolic and nutritional status changes after 10% weight loss in severely obese patients treated with laparoscopic surgery vs integrated medical treatment. Obes Surg 2007;17:1592–8. [7] Lubrano C, Mariani S, Badiali M, Cuzzolaro M, Barbaro G, Migliaccio S, et al. Metabolic or bariatric surgery? Long-term effects of malabsorptive vs restrictive bariatric techniques on body composition and cardiometabolic risk factors. Int J Obes (Lond) 2010;34:1404–14. [8] Ogden CL, Carroll MD, Curtin LR, McDowell MA, Tabak CJ, Flegal KM. Prevalence of overweight and obesity in the United States, 1999–2004. JAMA 2006;295:1549–55. [9] Vogels N, Diepvens K, Westerterp-Plantenga MS. Predictors of long-term weight maintenance. Obes Res 2005;13:2162–8. [10] Das SK, Roberts SB, McCrory MA, Hsu LK, Shikora SA, Kehayias JJ, et al. Long-term changes in energy expenditure and body composition after massive weight loss induced by gastric bypass surgery. Am J Clin Nutr 2003;78:22–30. [11] Coupaye M, Bouillot JL, Coussieu C, Guy-Grand B, Basdevant A, Oppert JM. One-year changes in energy expenditure and serum leptin following adjustable gastric banding in obese women. Obes Surg 2005;15:827–33. [12] Wadstrom C, Backman L, Forsberg AM, Nilsson E, Hultman E, Reizenstein P, et al. Body composition and muscle constituents during weight loss: studies in obese patients following gastroplasty. Obes Surg 2000;10:203–13. [13] Trumbo P, Schlicker S, Yates AA, Poos M. Food, Nutrition Board of the Institute of Medicine TNA. Dietary reference intakes for energy, carbohydrate, fiber, fat, fatty acids, cholesterol, protein and amino acids. J Am Diet Assoc 2002;102:1621–30. [14] United States. Dept. of Agriculture. Human Nutrition Information Service. Dietary Guidelines Advisory Committee., United States. Agricultural Research Service. Report of the Dietary Guidelines Advisory Committee on the dietary guidelines for Americans, 2010: to the Secretary of Agriculture and the Secretary of Health and Human Services. Washington, D.C.: United States Dept. of Agriculture, United States Dept. of Health and Human Services; 2010. vi, 445. [15] Thompson W. Guidelines for exercise testing and prescription. Baltimore, MD: Wolters Kluwer/Lippincott Williams; 2010. [16] Jebb SA, Cole TJ, Doman D, Murgatroyd PR, Prentice AM. Evaluation of the novel Tanita body-fat analyser to measure body composition by comparison with a four-compartment model. Br J Nutr 2000;83:115–22. [17] Jimenez A, Omana W, Flores L, Coves MJ, Bellido D, Perea V, et al. Prediction of whole-body and segmental body composition by bioelectrical impedance in morbidly obese subjects. Obes Surg 2012;22:587–93. [18] Chen SC, Lin YH, Huang HP, Hsu WL, Houng JY, Huang CK. Effect of conjugated linoleic acid supplementation on weight loss and body fat composition in a Chinese population. Nutrition 2012;28:559–65. [19] Andreu A, Moize V, Rodriguez L, Flores L, Vidal J. Protein intake, body composition, and protein status following bariatric surgery. Obes Surg 2010;20:1509–15.
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[29] Mechanick JI, Kushner RF, Sugerman HJ, Gonzalez-Campoy JM, CollazoClavell ML, Spitz AF, et al. American Association of Clinical Endocrinologists, The Obesity Society, and American Society for Metabolic & Bariatric Surgery medical guidelines for clinical practice for the perioperative nutritional, metabolic, and nonsurgical support of the bariatric surgery patient. Obesity (Silver Spring) 2009;17(Suppl 1):S1–70. v. [30] Faria SL, de Oliveira Kelly E, Lins RD, Faria OP. Nutritional management of weight regain after bariatric surgery. Obes Surg 2010;20:135–9. [31] Christiansen T, Bruun JM, Madsen EL, Richelsen B. Weight loss maintenance in severely obese adults after an intensive lifestyle intervention: 2- to 4-year follow-up. Obesity (Silver Spring) 2007;15:413–20. [32] Galtier F, Farret A, Verdier R, Barbotte E, Nocca D, Fabre JM, et al. Resting energy expenditure and fuel metabolism following laparoscopic adjustable gastric banding in severely obese women: relationships with excess weight lost. Int J Obes (Lond) 2006;30:1104–10. [33] Carrasco F, Rojas P, Csendes A, Codoceo J, Inostroza J, Basfi-fer K, et al. Changes in ghrelin concentrations one year after resective and nonresective gastric bypass: associations with weight loss and energy and macronutrient intakes. Nutrition 2012;28:757–61. [34] Siegrist M, Rank M, Wolfarth B, Langhof H, Haller B, Koenig W, et al. Leptin, adiponectin, and short-term and long-term weight loss after a lifestyle intervention in obese children. Nutrition 2013;2:851–7. [35] Marinilli Pinto A, Gorin AA, Raynor HA, Tate DF, Fava JL, Wing RR. Successful weight-loss maintenance in relation to method of weight loss. Obesity (Silver Spring) 2008;16:2456–61. [36] Zalesin KC, Franklin BA, Lillystone MA, Shamoun T, Krause KR, Chengelis DL, et al. Differential loss of fat and lean mass in the morbidly obese after bariatric surgery. Metab Syndr Relat Disord; 2010:15–20.
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Applied nutritional investigation
Medical weight loss versus bariatric surgery: Does method affect body composition and weight maintenance after 15% reduction in body weight? Michelle G. Kulovitz Ph.D. a, *, Deborah Kolkmeyer M.S. b, Carole A. Conn Ph.D. a, Deborah A. Cohen D.C.N. a, Robert T. Ferraro M.D. b a b
Department of Individual, Family, and Community Education, University of New Mexico, Albuquerque, New Mexico, USA Southwest Endocrinology Associates, Albuquerque, New Mexico, USA
a r t i c l e i n f o
a b s t r a c t
Article history: Received 15 January 2013 Accepted 11 June 2013
Objective: The aim of this study was to investigate body composition changes in fat mass (FM) to lean body mass (LBM) ratios following 15% body weight loss (WL) in both integrated medical treatment and bariatric surgery groups. Methods: Obese patients (body mass index [BMI] 46.6 6.5 kg/m2) who underwent laparoscopic gastric bypass surgery (BS), were matched with 24 patients undergoing integrated medical and behavioral treatment (MT). The BS and MT groups were evaluated for body weight, BMI, body composition, and waist circumference (WC) at baseline and after 15% WL. Results: Following 15% body WL, there were significant decreases in %FM and increased %LBM (P < 0.0001). Additionally, both groups saw 76% of WL from FM, and 24% from LBM indicating a 3:1 ratio of FM to LBM loss during the first 15% reduction in body weight. Finally, no significant differences (P ¼ 0.103) between groups for maintenance of WL at 1 y were found. For both groups, baseline FM was found to be negatively correlated with percentage of weight regained (%WR) at 1 y post-WL (r ¼ 0.457; P ¼ 0.007). Baseline WC and rate of WL to 15% were significant predictors of %WR only in the BS group (r ¼ 0.713; P ¼ 0.020). Conclusion: If followed closely by professionals during the first 15% body WL, patients losing 15% weight by either medical or surgical treatments can attain similar FM:LBM loss ratios and can maintain WL for 1 y. Ó 2014 Elsevier Inc. All rights reserved.
Keywords: Bariatric surgery Weight loss Body composition Obesity Weight maintenance Lean mass Fat mass
Introduction With obesity rates and corresponding health risks rising each year, health professionals have been dedicated to understanding the physiological mechanisms of weight loss (WL), as well as the ability to keep their patients’ weight stable following significant WL [1]. According to the National Heart, Lung, and Blood Institute’s (NHLBI) current guidelines for clinicians, successful WL for obese individuals is defined as a 10% reduction in initial MGK was responsible for design and concept of project, imputing data collected, writing manuscript, creating figures, interpretation of data, and statistical analysis of data. CAC was responsible for design and concept of project, interpretation of data, editing and writing of manuscript. DA was responsible for design and concept of project, data collection, and editing and writing manuscript. DC was responsible for editing and writing manuscript as well as interpretation of data. RTF was responsible for editing manuscript. * Corresponding author. Tel.: þ1 505 277 2658; fax: þ1 505 277 6227. E-mail address: [email protected] (M. G. Kulovitz). 0899-9007/$ - see front matter Ó 2014 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.nut.2013.06.008
body weight that is maintained for at least 1 y [1–4]. Current research has stated that maintaining WL for >1 y using integrated medical treatment or bariatric surgery (BS) is largely predicted by a high baseline fat mass (FM), in conjunction with other metabolic factors, that favor the preservation of lean body mass (LBM) as percentage of body weight (%LBM) [5–11]. Understanding the differences between therapeutic approaches to losing excess weight for obese individuals is important to determine if there are differences in predictors of sustained WL. Currently, limited research exists comparing WL approaches through the use of integrated medical and behavioral treatment (MT) and the use of laparoscopic gastric bypass BS. The use of BS increased nearly sixfold between 1990 and 2000 in the United States, averaging from 2.4 to 14.1 per 100,000 adults [4]. Currently, BS serves as one of the fastest and most effective WL techniques for severely obese individuals that can maintain a significant loss of weight over time [3,5]. Existing research has found that gastric bypass BS patients can lose an
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average of 11.8% and 28.5% of initial body weight, with a %LBM loss of 9.4% and 20.3% in 30 d and 180 d, respectively [5]. WL with BS patients has been shown to alter body composition dramatically and unfavorably by decreasing both FM and LBM at the same rate [12]. Results of a 2000 study were similar to those obtained in a later study that compared laparoscopic gastric bypass BS to MT [6,12]. BS patients showed a 10% WL with equal amounts of %LBM and %FM loss at 6 wk, whereas MT resulted in a 10% WL at 30 wk with an increase of 5.2% in %LBM [6]. Due to the rapid WL seen with BS, there is a need to further understand the effect BS and rate of weight loss (RWL) has on body composition when compared with MT [4,5]. Past research has only focused on the anthropometric marker of 10% of initial body weight reduction as defined by the NHLBI, yet BS surgery and MT patients may experience WL in excess of this. Past research has indicated that some metabolic markers and nutritional status changes do occur after a 10% decrease in initial body weight, however, the 15% marker has yet to be investigated [6]. To our knowledge, it is not known if losing more than the NHLBI guidelines of 10% initial body weight, provides the same reductions in %FM and %LBM for both BS and MT patients and permits successful maintenance of WL over 1 y or more. The key objective of this study was to determine if using either MT or BS to induce WL to 15% initial body weight will alter the final ratio of FM:LBM. Additionally, this study investigated influences of treatment on weight maintenance after 1 y of 15% WL. Additionally, there is no known research comparing RWL to 15% between BS and MT patients. The understanding of the ratio between FM:LBM loss for both BS and MT patients will help clinicians better understand what to expect when patients lose 15% of initial body weight or more and what can help predict WL maintenance over time using either treatment. Methods Participant selection The data included in this study are part of a continuous collection by the Southwest Endocrinology Associates Weight Management Center (SWENDO) from January 2010 to January 2012 where at least 400 active patients in Albuquerque, New Mexico are currently enlisted. SWENDO’s comprehensive program includes a medical team of physicians, physician assistants, registered dietitians, exercise physiologists/personal trainers, nurse/medical assistants, and mentors all trained to perform analysis of patients. Participants were included in the study if they reached a 15% reduction in initial body weight while under the care of SWENDO; they were in medically supervised WL program at SWENDO only or had laparoscopic gastric bypass BS while under the care of SWENDO; their medical charts contained all data needed including dates of measurements, age, sex, body weight, height, waist circumference (WC), and body composition analysis; and they were actively enrolled in SWENDO weight management program during the 15% WL period. All participants gave written consent for all treatment data to be used for research purposes and this study was granted approval for use by the University of New Mexico Institutional Review Board.
Participant demographics The study population (N ¼ 48) included both men (n ¼ 6) and women (n ¼ 42), ages ranging from 26 to 68 y with a mean age of 50.4 9.9 y, of various ethnicities who reside in the state of New Mexico, and are under the care of SWENDO weight management program. Participant data were split into two groups: BS group (n ¼ 24) and MT group (n ¼ 24). Both groups were similar for baseline age at initial WL, sex, and initial body mass index (BMI) with no significant differences as shown in Table 1. Measurements included in the study were taken at baseline before WL, after approximately 15% body WL, and at 1 y following achievement of 15% loss, if available. Due to study duration, some patients did not reach 1-y post 15% WL simply because of the dates established to frame the duration of the analysis period. This did cause limited 1-y follow-up
Table 1 Characteristics of participants
Number of participants Age (y) Weight (kg) Initial BMI (kg/m2) FM (kg) LBM (kg) Days to 15% WL Initial %BF %WL
Medical treatment (N ¼ 24)
Bariatric surgery (N ¼ 24)
(F ¼ 21; M ¼ 3) 50.1 10.0 120.6 20.3 45.28 6.3 59.0 11.4 61.6 13.7 295.2 347.9 50.5 5.5 17.0 3.1
(F ¼ 21; M ¼ 3) 50.7 10.1 126.6 20.9 46.6 6.5 63.8 13.1 62.8 12.6 151.2 85.5 50.3 5.4 18.3 2.8
BMI, body mass index; %BF, percent body fat; LBM, lean body mass; FM, fat mass; %WL, percent weight loss
data. Percent weight regain (%WR) is defined as the change in weight, either positive or negative, from the 15% WL marker. Medically supervised treatment group Participants included in the MT group underwent highly individualized treatment programs with professional guidance while under the care of SWENDO. Supervised medical individualized treatment options determined by the participant and SWENDO professionals included some or all of the following: group support classes, individualized coaching/counseling sessions, and full dietary meal planning. All MT patients were recommended a calorie-deficit diet to target 500 to 2000 kcal/d and achieve no more than an average of a 1% reduction in body weight weekly. Food plans are negotiated with each individual based on their personal needs, however, on average, MT patients consumed between 45% and 65% of total calories from carbohydrates, 25% and 35% of total calories from protein, and between 20% and 35% of total calories from fat. All MT patients kept food journals and were monitored by SWENDO professionals. This macronutrient breakdown follows the guidelines provided by the Institute of Medicine (IOM) and the 2010 Dietary Guidelines for Americans, however, tended to be on the higher composition for protein (80–100 g/d), lower composition of fat, and moderate intake of carbohydrates [13,14]. MT patients also could have used partial and/or full Optifast Ò meal replacements and/or pharmacologic WL agents (phentermine and diethyproprion). Meal replacements and/or portion-controlled meals were strongly encouraged at least as part of the patient’s diet. The uses of medications were introduced as needed and often used intermittently. It could be estimated that at any point in time, about 25% of the total active clients enrolled in a SWENDO program are in possession of a current prescription for either diethylproprion (25 mg one to three times daily) or phentermine 37.5 mg (one-half to one tablet daily). Patients who participated in the program could choose their personal methods of WL with support from the SWENDO medical team. Laparoscopic roux-en-Y gastric bypass bariatric surgery group Similar to participants in the MT group, those included in the BS group also were members of the SWENDO comprehensive program where they had access to the same weekly group support classes and education, individualized coaching/counseling sessions, and individualized dietary meal planning. Before and after laparoscopic Roux-en-Y gastric bypass surgery, patients were educated on their specific diet post-surgery. The early postoperative nutritional plan was very regimented and included a soft diet of mostly protein and one or more protein shakes (totaling 80–100 g of protein) daily. Total daily calorie intake remains at 0.05), initial FM (63.8 13.1 kg versus 59.0 0.4 kg; P > 0.05), and initial LBM (62.8 12.6 kg versus 61.6 13.7 kg; P > 0.05) (Table 1). Following approximately 15% body WL both the BS group and the MT group had similar reductions in body weight with no significant differences, 23.4 6.2 kg versus 20.8 5.3 kg; P > 0.05 (8.5 1.9 kg/m2 versus 7.8 1.9 kg/m2; P > 0.05). Additionally, both groups were found to have significant changes in distribution of %FM and %LBM within groups. In the BS group %FM decreased (50.3% 5.4% to 44.3% 6.7%; P < 0.0001), whereas %LBM increased (49.7% 5.4% to 55.7% 6.7%; P < 0.0001), and in the MT group %FM decreased (49.0% 5.5% to 43.3% 5.7%; P < 0.0001), whereas %LBM increased (51.0 5.5 to 56.7 5.7%; P < 0.0001). Contrary to previous research findings, these body composition results were similar and not significantly different (P > 0.05) between the BS and the MT groups as reported in Table 2 [6]. Additionally, no significant differences in FM and LBM reductions between groups were found [6]. Following 15% WL for both the BS and MT groups saw approximately 76% of WL from FM, and 24% from LBM indicating an approximate 3:1 ratio of FM to LBM loss [6]. As stated in Table 2, both groups saw significant losses from baseline in the FM:LBM ratio, whereas there was no statistically significant differences between the final FM:LBM ratios for the MT and BS groups. To investigate predictors of weight maintenance at 1 y, simple and multiple regression analysis were conducted. There were no significant differences (P ¼ 0.103) between groups for weight maintenance, where weight maintenance at 1 y was expressed as a %WR 1 y following the achievement of approximately 15% weight loss. For combined groups (n ¼ 34) baseline FM was
51
Weight (kg) BMI (kg/m2) WC (cm) %BF LBM (kg) LBM (%) FM (kg) FM (%) FM:LBM
Medical treatment
Bariatric surgery
Before
After
Before
100 17.2* 37.5 5.2* 110.5 10.6* 43.3 5.7* 56.7 12.1* 56.7 5.7* 43.3 9.7* 43.3 5.7* 0.8 0.2*
126.6 46.6 131.2 50.3 62.8 49.7 63.8 50.3 1.03
120.6 45.28 123.7 50.5 61.6 51.0 59.0 49.0 1.06
20.3 6.3 12.7 5.5 13.8 5.5 11.4 5.5 0.21
20.9 6.5 4.2 5.4 12.6 5.4 13.1 5.4 0.209
After 103.3 16.3* 38.1 5.3* 116.1 4.0* 44.3 6.7* 57.3 11.0* 55.7 6.7* 46.0 11.1* 44.3 6.7* 0.8 0.2*
WL, weight loss; BMI, body mass index; WC, waist circumference; %BF, percent body fat; LBM, lean body mass; FM, fat mass; FM:LBM, ratio of fat mass to lean body mass * P < 0.05 vs. baseline.
found to be significant and negatively correlated with %WR at 1 y post-WL (r ¼ –0.457; P ¼ 0.007) as shown in Figure 1. All patients with data at 1 y following 15% WL, were able to keep most of the weight lost at 1 y, however, the BS group tended to continue to lose weight at 1 y compared with the MT group (not significantly different) (Fig. 2). When differentiating predictors between groups, multiple regression analysis showed that the combination of baseline WC and RWL are a significant predictor of %WR only in the BS group (r ¼ 0.713; P ¼ 0.020). No predictors for %WR were statistically significant for the MT group. Other variables at baseline (age, LBM, %LBM, %FM, %BF) did not contribute to the change in %WR at 1 y in either group. Due to a limited study duration where some patients had yet to reach 1 y post-15%WL, there was limited 1-y follow-up data. Only 15 BS and 19 MT patients contained data to 1 y post-WL and were included in the regression analysis and weight maintenance trend (Figs. 1 and 2, respectively). Discussion According to the NHLBI, there are several known effective WL treatments that exist for obesity management that include integrated medical, behavioral, and surgical treatments. Published studies have found variable results with regards to body composition changes that occur following these treatments [1]. Additionally, there are several therapeutic strategies currently being investigated as potential treatments to aid in body WL or optimize body composition ratios during WL; however, more
Fig. 1. Percent body weight regain from 15% WL as a function of FM at baseline in a subset of both MT (n ¼ 19) and BS (n ¼ 15) patients who had 1-y follow-up data available for analysis (r ¼ 0.457; P < 0.05).
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Fig. 2. Available participant data for average weight (kg) in both the BS (n ¼ 15) and MT (n ¼ 19) groups that had available data at 1 y post-15% WL. Body weights at baseline, 15% weight loss, and at 1 y following 15% weight loss were included. No significant differences were found between groups (P > 0.05).
research is needed to investigate WL to 15% initial body WL [18, 19]. In this study, both the BS and MT groups lost approximately 15% of their initial body weight due to negative energy balance. Because both groups were supervised during their WL period by the SWENDO weight management center, care for both groups was similar and consistent. Given that both groups were provided with individualized diet therapy that was tailored to their individual needs, we hypothesize that ensuring adequate protein intake to preserve LBM was vital. Dietary protein intake following massive body WL > 10%, is considered necessary to preserve LBM, nutritional status, and satiety during WL [3,6,20, 21]. Additionally, high-protein intake following body WL has been shown to contribute to a 50% lower body weight regain than consumption of a higher-carbohydrate and lower-protein diet [21]. Maintaining LBM is a concern with any population where large decreases in body weight occur in a short period of time [2, 3,5,6,9]. It appears that use the BIA as a measurement of change in body composition in obese undergoing WL has been accepted in the literature [22]. According to one study (1999), obese individuals (BMI 25–65 kg/m2) undergoing WL were assessed using both hydrostatic weighing, the current gold standard for assessing body composition, and BIA [22]. No significant differences were found in assessing FM changes in the study population. Similarly, BIA was validated against deuterium oxide dilution (D2O) using hydrometry [23]. No significant differences were found when patients adhered to pretest guidelines for BIA as did our study population. A 2011 study questioned the reliability of BIA in morbidly obese patients (BMI 36.2–45.4 kg/m2) undergoing bariatric surgery and rapid WL [24]. The study found that BIA limitations in terms of body water and FM were more relevant for males than females. The BIA was found to be valid and reliable in female patients. Because our study population was 48 women versus 6 men, we believe this could contribute to a marginal amount of error. Furthermore, previous studies have reported that BIA can overestimate FM and underestimated FM compared to dual-energy X-ray absorptiometry (DXA) [25], whereas DXA is known to underestimate LBM and overestimate FM in obese individuals when compared with the four-compartment model [26]. If the assumptions of the BIA are true, because the present study is only addressing the change in FM:LBM ratio, it is assumed that all participants will have overestimated LBM and underestimated FM equally between groups. Thus, the ratio between FM:LBM is not affected. No significant differences between groups were found in losses of absolute FM and LBM, as well as %FM and %LBM. WL of both
the BS and MT groups to 15% saw 76% of WL from FM, and 24% from LBM in 151.2 85.5 d versus 295.2 347.9 d, respectively. These results suggest that the first 15% of body WL could have a 3:1 ratio of FM:LBM loss in both BS and MT populations when cared for by weight management professionals. The results of the BS group were consistent with a previous study in which a 3:1 ratio of FM:LBM loss was seen after 6 mo (182 d) and also after 1 y. Additionally, similar results were seen in a 3:1 ratio of FM:LBM loss in the MT group in a study that compared MT with BS patients to 10% WL [6,27]. Contrary to our results, body WL in that study’s BS patients saw a 1:1 ratio of FM:LBM loss where exercise was not discussed as an emphasis in their BS group [6]. Additionally, our results are supported by research done in an earlier study that found that implementation of resistance training along with a hypocaloric diet during WL can preserve more LBM [28]. Results of this current study may imply that from baseline to a 15% reduction in body weight until approximately 1 y of WL, the ratio of FM:LBM is 3:1 with supervised care. Furthermore, for patients undergoing BS under the care of weight management professionals where individualized diet and exercise prescriptions are used, surgery can yield similar results in distribution of body composition and preservation of LBM as an intensive lifestyle intervention. As displayed in Table 2, results of this study indicate that both the BS and the MT groups decreased their %FM and increased their %LBM. This finding was different from previous research comparing MT with BS patients. Previous researchers saw a significant decrease in %FM and increase in %LBM in the MT group only, however, the BS group remained unchanged in %FM and %LBM [6]. Similar results were found in a study that observed RWL in BS patients only, where a 1:1 ratio of %FM to % LBM loss was reported in this population [12]. The similar RWL seen in both groups with a concurrent increase in %LBM could be attributed to the higher protein diet of 80 to 100 g/d in combination with a hypocaloric-individualized diet. Current research assessing 80 g protein for women and 100 g protein for men on LBM preservation after BS revealed that higher protein intakes resulted in less weight regain after 2 y postsurgery [19]. Whether the WL approach is through the use of integrated MT or the use of laparoscopic gastric bypass BS, the integration of adequate protein in the diet and incorporation of physical activity to preserve LBM is of utmost importance [1,3,4, 8,9,12]. Although current practice may suggest a higher protein need to preserve LBM, the current guidelines from the American Association of Clinical Endocrinologists (AACE) specific for nutrition support of BS patients who have undergone gastric bypass recommend an intake of protein 60 g/d [6,19,29,30]. The protein intake recommended to BS patients at SWENDO is currently greater than the recommended intake of 60 g/d recommended by the AACE and may have contributed to the greater preservation of LBM in the present study. This study found no significant differences between RWL to 15% using BS or MT techniques, however, it may be clinically significant that mean RWL between groups was almost double in BS (151.2 85.5 d versus 295.2 347.9 d, respectively). The nonsignificant differences seen in RWL between groups is in contrast to previous findings by others where MT groups saw an average WL to 10% at 182 d and BS patients at 42 d [6]. Large standard deviations were seen with the RWL variable in the MT group indicating fluctuating WL and weight regain before reaching a 15% WL goal in the MT group. Weight maintenance 1 y following a 15% reduction in body weight was similar between groups with no significant differences (Fig. 2). Whereas many studies have shown weight
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regain following significant weight loss, the individualized care received from the SWENDO team, weight regain was negative (i.e., continued loss) after 1 y. This finding can imply that no matter whether the method of WL is BS or MT, the WL can be maintained in clinically supervised patients [3,9,31]. Of the individuals monitored for 1 y post-15% WL, all individuals in the BS group were able to maintain or continue to lose weight after 1 y. Although still below their baseline weight, two individuals in the MT group gained weight from their body weight measured at 15% WL (Fig. 1). Both groups were combined to determine a common predictor of %WR at 1 y. Baseline FM was a significant predictor for both groups to determine %WR following 15% WL (Fig. 1). Regardless of group, individuals with higher baseline FM regained less or lost more weight after 1 y. This result is consistent with previous research studying both BS and MT populations [9–11]. This outcome can be explained because obese individuals have higher %BF indicating an unhealthy body composition [17,24]. In order to reach a healthier FM:LBM ratio, obese individuals typically lose mostly FM quicker than leaner individuals in a shorter period of time when a hypocaloric diet with adequate protein and exercise are used [9]. Analysis between groups indicated that the combination of baseline WC and RWL was a significant predictor of %WR at 1 y in the BS group only (r ¼ 0.713; P ¼ 0.020). When these predictors are taken together, the results suggest that the BS patients losing weight at a slower rate and having a larger WC at baseline tend to lose more weight over the course of 1 y following 15% WL. It can be argued that a larger WC could indicate more abdominal fat, perhaps indicating increased baseline FM. Similar findings were found in a study that showed gradual and sustained WL following surgery in patients who underwent laparoscopic adjustable gastric banding [32]. Furthermore, recent WL studies investigating hormonal influences before and 12 mo after Roux-en-Y gastric bypass surgery in adults (i.e., serum-ghrelin) [33] or after an intensive lifestyle intervention in children (i.e., leptin and adiponectin) [34], have shown that hormonal influences may have a predictive value in WL; however, these are still not fully understood. Because weight maintenance after WL is a multifactorial issue in patients and is a combined effect of baseline body composition, and many other mechanisms still not fully understood, these results are limited to this clinical study population only [3,9,35,36]. Our study has limitations common to small retrospective studies. Our population included free-living men and women that were pre- or postmenopausal and were of different age categories. One-y weight follow-up data was limited within the participants studied due to time limitations for data analysis. Some patients had yet to reach 1 y following attainment of 15% WL. Additionally, participants were self-selected into treatments so they could not be randomized. Large SDs were found with MT patients who had weight fluctuations throughout the 15% WL period. More research is needed with a larger sample size to study 15% WL comparing both populations. Although we speculate that the higher-protein recommendation and/or individualized exercise prescriptions contribute to the beneficial 3:1 ratio of FM:LBM loss in both MT and BS patients, future studies should measure actual intake and exercise levels to test these hypotheses. The novelty of the present study also could be seen as a limitation. Because study participants were free-living patients with direct influences on treatment, dietary and physical activity recommendations were individualized to each patient and not standardized. We believe that this does provide an opportunity to further the literature in free-living clinical populations where individualized treatment is prescribed. Due to the retrospective
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nature of this study, future research is necessary to provide evidence that these outcomes may occur in a study population with a controlled experimental design. Conclusion The findings of this study strengthen the efficacy of WL to 15% initial body weight for both medical and surgical treatments for obesity. If followed closely by well-qualified medical teams during the first 15% of initial body weight loss, patients losing weight using either treatment can be successful in maintaining similar FM:LBM ratios during weight loss and are able to keep the weight off for at least 1 y. References [1] National Heart Lung and Blood Institute. Clinical Guidelines on the Identification, Evaluation, and Treatment of Overweight and Obesity in AdultsdThe Evidence Report. National Institutes of Health. Obes Res 1998;6(Suppl 2):51S–209S. [2] Nackers LM, Ross KM, Perri MG. The association between rate of initial weight loss and long-term success in obesity treatment: does slow and steady win the race? Int J Behav Med 2010;17:161–7. [3] Wing RR, Hill JO. Successful weight loss maintenance. Annu Rev Nutr 2001;21:323–41. [4] Trus TL, Pope GD, Finlayson SR. National trends in utilization and outcomes of bariatric surgery. Surg Endosc 2005;19:616–20. [5] de Aquino LA, Pereira SE, de Souza Silva J, Sobrinho CJ, Ramalho A. Bariatric surgery: impact on body composition after Roux-en-Y gastric bypass. Obes Surg 2012;22:195–200. [6] del Genio F, Alfonsi L, Marra M, Finelli C, del Genio G, Rossetti G, et al. Metabolic and nutritional status changes after 10% weight loss in severely obese patients treated with laparoscopic surgery vs integrated medical treatment. Obes Surg 2007;17:1592–8. [7] Lubrano C, Mariani S, Badiali M, Cuzzolaro M, Barbaro G, Migliaccio S, et al. Metabolic or bariatric surgery? Long-term effects of malabsorptive vs restrictive bariatric techniques on body composition and cardiometabolic risk factors. Int J Obes (Lond) 2010;34:1404–14. [8] Ogden CL, Carroll MD, Curtin LR, McDowell MA, Tabak CJ, Flegal KM. Prevalence of overweight and obesity in the United States, 1999–2004. JAMA 2006;295:1549–55. [9] Vogels N, Diepvens K, Westerterp-Plantenga MS. Predictors of long-term weight maintenance. Obes Res 2005;13:2162–8. [10] Das SK, Roberts SB, McCrory MA, Hsu LK, Shikora SA, Kehayias JJ, et al. Long-term changes in energy expenditure and body composition after massive weight loss induced by gastric bypass surgery. Am J Clin Nutr 2003;78:22–30. [11] Coupaye M, Bouillot JL, Coussieu C, Guy-Grand B, Basdevant A, Oppert JM. One-year changes in energy expenditure and serum leptin following adjustable gastric banding in obese women. Obes Surg 2005;15:827–33. [12] Wadstrom C, Backman L, Forsberg AM, Nilsson E, Hultman E, Reizenstein P, et al. Body composition and muscle constituents during weight loss: studies in obese patients following gastroplasty. Obes Surg 2000;10:203–13. [13] Trumbo P, Schlicker S, Yates AA, Poos M. Food, Nutrition Board of the Institute of Medicine TNA. Dietary reference intakes for energy, carbohydrate, fiber, fat, fatty acids, cholesterol, protein and amino acids. J Am Diet Assoc 2002;102:1621–30. [14] United States. Dept. of Agriculture. Human Nutrition Information Service. Dietary Guidelines Advisory Committee., United States. Agricultural Research Service. Report of the Dietary Guidelines Advisory Committee on the dietary guidelines for Americans, 2010: to the Secretary of Agriculture and the Secretary of Health and Human Services. Washington, D.C.: United States Dept. of Agriculture, United States Dept. of Health and Human Services; 2010. vi, 445. [15] Thompson W. Guidelines for exercise testing and prescription. Baltimore, MD: Wolters Kluwer/Lippincott Williams; 2010. [16] Jebb SA, Cole TJ, Doman D, Murgatroyd PR, Prentice AM. Evaluation of the novel Tanita body-fat analyser to measure body composition by comparison with a four-compartment model. Br J Nutr 2000;83:115–22. [17] Jimenez A, Omana W, Flores L, Coves MJ, Bellido D, Perea V, et al. Prediction of whole-body and segmental body composition by bioelectrical impedance in morbidly obese subjects. Obes Surg 2012;22:587–93. [18] Chen SC, Lin YH, Huang HP, Hsu WL, Houng JY, Huang CK. Effect of conjugated linoleic acid supplementation on weight loss and body fat composition in a Chinese population. Nutrition 2012;28:559–65. [19] Andreu A, Moize V, Rodriguez L, Flores L, Vidal J. Protein intake, body composition, and protein status following bariatric surgery. Obes Surg 2010;20:1509–15.
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