HEALTH PSYCHOLOGY, 1992, ii(SuppL), 1-3 Copyright © 1992, Lawrence Erlbaum Associates, Inc.
Understanding the Relations Between Smoking and Body Weight and Their Importance to Smoking Cessation and Relapse Robert C. Klesges Center for Applied Psychological Research Memphis State University
Sally A. Shumaker
This document is copyrighted by the American Psychological Association or one of its allied publishers. This article is intended solely for the personal use of the individual user and is not to be disseminated broadly.
Bowman Gray School of Medicine Wake Forest University
A conference on smoking and body weight was conducted September 10 to 13,1990, at Memphis State University, Memphis, Tennessee. Approximately 40 participants and 100 interested professionals were involved in the 4-day conference in which the primary goal was to bring together a multidisciplinary team of scientists to consider the complex relations between smoking and body weight and to suggest the most appropriate research methods for investigating these relations. Co-sponsored by Memphis State University and the National Heart, Lung, and Blood Institute (NHLBI) of the National Institutes of Health, the conference included a series of theory-based and empirically based presentations by leading experts in the fields of smoking behavior, diet and nutrition, weight control, exercise, and energy expenditure. Formal presentations were made—see abstracts appearing in this supplement—and working groups composed of representatives from the various relevant disciplines discussed, in detail, current theoretical models and state-of-the-art methods to guide research on the relations between smoking and body weight and to address the implications of these relations to smoking initiation, cessation, and relapse. These groups met throughout the conference, and the results of their deliberations form the basis for this Health Psychology supplement.
WHY STUDY RELATIONS BETWEEN SMOKING AND BODY WEIGHT? Most people are aware that smoking is closely related to cancer, emphysema, and heart disease. However, the magnitude of the health problems associated with smoking is often not fully appreciated. More than 40,000 studies have documented the relation between smoking and health, and close to 500,000 people die of smoking in the United States each year (U.S. Department of Health and Human Services [USDHHS], 1990). A recent 10-year follow-up study of more than 361,000 participants in the Multiple Risk Factor Intervention Trial (MRFIT) revealed that approximately half of all deaths were associated with cigarette smoking. Although the incidence rate of cigarette smoking in the United States is declining, the decrease in smoking has been much greater in men than in women (Pierce, Fiore, Novotny, Hatziandreu, & Davis, 1989). It is estimated that the number of female smokers will equal the number of male smokers by 1995 (Pierce et al., 1989). With the increased relative number of women smokers comes increased Address all correspondence and requests for reprints for this supplement to Robert C. Klesges, Department of Psychology, Center for Applied Psychological Research, Memphis State University, Memphis, TN 38152.
smoking-related disease. For example, lung cancer is now more prevalent than breast cancer in women (American Cancer Society, 1990). Although the reasons for the increased relative incidence of smoking among women are not known, one contributory factor appears to be the widespread belief that smoking controls body weight (Pirie, Murray, & Leupker, 1991). Indeed, recent epidemiological studies have confirmed that cigarette smokers weigh less than comparable-age nonsmokers (Gordon, Kannel, Dawber, & McGee, 1975; D. R. Jacobs & Gottenborg, 1981), that individuals who start smoking lose weight (Lund-Larsen & Tretli, 1982), and that many smokers who quit smoking gain weight (Coates & Li, 1983; Hall, Ginsberg, & R. J. Jones, 1986; Manley & Boland, 1983; Noppa & Bengtsson, 1980; Schoenenberger, 1982). Reviews of the relation between smoking cessation and weight gain have estimated the average weight gain following smoking cessation to be between 4.5 and 7.5 lb (R. C. Klesges, Meyers, L. M. Klesges, & LaVasque, 1989; USDHHS, 1990). However, recent studies have suggested that certain groups of individuals may be at risk for large amounts of weight gain following cessation. Based on a longitudinal analysis of 9,332 participants in the First National Health and Nutrition Examination Survey (NHANES 1), average weight gain among women who quit smoking was greater (8.4 lb) than among men who quit smoking (6.2 lb; Williamson et al., 1991). Major weight gain (defined as a weight gain of more than 28.6 lb) occurred in 13.4% of the women and in 9.8% of the men who quit smoking. Blacks, people under the age of 55, people smoking more cigarettes per day, and people who were less obese at baseline were at most risk for large weight gains (Gerace, Hollis, Ockene, & Svendsen, 1991; Williamson et al., 1991). The weight gain following smoking cessation may produce undesirable health problems, although these are probably modest given the large health benefits of quitting smoking (Kuller et al., 1991). For example, a recent study of 3,470 participants of MRFIT revealed that the onset of hypertension was higher in those who quit smoking (35%) than in those who continued to smoke (27%; Gerace et al., 1991). Weight gain following cessation was largely responsible for this increased incidence of hypertension in quitters. Given the large body of literature that supports a link between smoking cessation and weight gain, it may be surprising to learn that there is little known regarding the reasons (mechanisms) for postcessation weight gain. A recent review (USDHHS, 1990) summarized the available data on the predictors of postcessation weight gain. In the area of dietary intake, of 8 studies reported, only 2 provided strong support for dietary changes following cessation, 4 provided qualified support for dietary changes following cessation (e.g., changes in nutrients but no changes in total dietary intake), and
This document is copyrighted by the American Psychological Association or one of its allied publishers. This article is intended solely for the personal use of the individual user and is not to be disseminated broadly.
2
KLESGES AND SHUMAKER
2 reported no changes in dietary intake following cessation (USDHHS, 1990). Of 14 studies assessing the metabolic contribution of smoking, only 8 (57%) found either acute or chronic increases in metabolic rate following smoking or decreases in metabolic rate after smoking cessation (USDHHS, 1990). The one area in which consistent findings emerge is the evidence that physical activity does not appear to change following smoking cessation. However, the number of studies evaluating physical activity has been limited (USDHHS, 1990). Although those who quit smoking are at higher risk for a major weight gain relative to those who continue to smoke (USDHHS, 1990), the average weight gain for the typical smoker is minimal from a health standpoint (4.5 to 7.5 lb; R. C. Klesges, Meyers, L. M. Klesges, & LaVasque, 1989; USDHHS, 1990). Yet, concern regarding postcessation weight gain appears to be a powerful motivator for continued smoking (R. C. Klesges & L. M. Klesges, 1988). A recent survey of 6,711 young adults (Pirie et al., 1991) indicated that substantially more female smokers than male smokers reported concern about weight gain if they quit smoking (58% vs. 26%). Regular smokers are much more concerned about body weight than ex-smokers, and smokers not intending to quit are much more likely to be concerned about weight gain than smokers intending to quit (R. C. Klesges, Somes et al., 1988; Weekley, R. C. Klesges, & Reylea, in press). Concerns about postcessation weight gain appeared to predict cessation in a recent stop-smoking program (R. C. Klesges, K. Brown et al., 1988). Finally, in the area of smoking initiation, weight-control beliefs related to smoking reliably predicted adolescent smokers versus those who tried smoking but later quit (Camp, R. C. Klesges, & Reylea, in press). These weight-control beliefs were predictive even after controlling for other strong predictors of smoking onset (e.g., number of peers who smoke; Camp et al., in press). It appears that concerns or beliefs regarding postcessation weight gain are more important than actual weight gain and may be associated with continued maintenance of smoking (Hall et al., 1986).
SETTING A NATIONAL AGENDA Given the important relation between smoking and body weight, Memphis State University and the NHLBI organized the 1990 conference with two major goals in mind: (a) to summarize what is known regarding the relation between smoking and body weight and (b) to set an agenda for future research. Other than knowing that people gain weight following smoking cessation (and that smokers are concerned about this), surprisingly little is known. For example, we need to know more about who is likely to gain the most weight following smoking cessation. We also need to better understand the cause(s) of postcessation weight gain. Given that the determinants of weight gain in nonsmokers are different in males versus females (R. C. Klesges, L. M. Klesges, Haddock, & Eck, 1992), one might expect different relative dietary versus metabolic contributions of postcessation weight gain as a function of gender and, perhaps, race, age, and the number of cigarettes smoked per day. We also need better information on who is smoking for weight control and how strongly weight control motivates smoking behavior. Gender appears to be an important predictor of concerns related to postcessation weight gain (R. C. Klesges & L. M. Klesges, 1988; Pirie et al., 1991), but other factors may also be important. For
example, in the Camp et al. (in press) study of smoking initiation, smoking for weight control was exclusively observed in White Americans—not a single Black American smoker reported smoking for weight control. Given the degree to which beliefs and, to some extent, misconceptions about the amount of weight gain appear to influence smoking maintenance, we need to educate smokers about the small actual weight-gain risk associated with cessation. Finally, and perhaps most important, we need to develop and evaluate interventions to reduce postcessation weight gain for those people at risk of major weight gain following smoking cessation and for those for whom a small weight gain (e.g., people with diabetes) may place them at medical risk. We also need to develop interventions either to reduce postcessation weight gain or to address concerns related to postcessation weight gain for those unwilling to quit smoking even if a small weight gain is observed.
ORGANIZATION OF THE SUPPLEMENT The articles that follow are the end result of a year of planning; 4 grueling days of working groups, writing sessions, and presentations; and almost a year of writing, editing, and consensus gathering. The initial papers resulted from the deliberations of the working groups. The Task Force 1 report, "Mechanisms Relevant to the Relation Between Cigarette Smoking and Body Weight," details the mechanisms by which smoking may have an effect on body weight. The Task Force 2 report, "Methods of Assessment: Strategies for Research," includes a review of the methodological and measurement issues inherent in the study of the relation between smoking and body weight, as well as the strengths and weaknesses of procedures for the assessment of energy balance (i.e., dietary intake, physical activity, and metabolic rate), and smoking in both animal and human models. The Task Force 3 report, "Implications With Respect to Prevention and Interventions," reviews prevention and intervention strategies for the treatment of weight gain following smoking cessation. Following these reports is Neil Grunberg's article, "Cigarette Smoking and Body Weight: A Personal Journey Through a Complex Field," in which he draws on his own experiences to describe the various disciplines needed to conduct research on the relation between smoking and body weight. Evan Pattishal then provides a synthesis of the conference in "Smoking and Body Weight: Reactions and Perspectives." Following Pettishal's article is a collection of the formal presentations (abstracts) made at the conference and the discussants' commentaries. Last, the references at the end of the supplement represent a comprehensive bibliography of the smoking and body weight literature. This supplement should provide the impetus for research in the area of smoking and body weight that incorporates the necessary multidisciplinary approach coupled with the most current theoretical models and research methods. Perhaps more important, this contribution highlights the importance of regular communication among scientists working in related but different fields of research. Many of the outstanding and well-known findings, methodologies, and investigators within one area of inquiry may be unknown to investigators who study different problems within the same discipline or the same question from the perspectives of different disciplines. As technologies have grown, as the number of scientists has increased, and as the number of specialty journals has proliferated, the need for
RELATIONS BETWEEN SMOKING AND BODY WEIGHT
meaningful communication through working conferences and multidisciplinary, problem-oriented research has increased. ACKNOWLEDGMENTS
This document is copyrighted by the American Psychological Association or one of its allied publishers. This article is intended solely for the personal use of the individual user and is not to be disseminated broadly.
The introduction to this supplement was supported by National Heart, Lung, and Blood Institute (NHLBI) Grants HL-45057 and HL-46352 to Robert C. Klesges. Robert C. Klesges and Sally A. Shumaker contributed equally to preparation of this supplement. We thank a few individuals without whom this conference would
3
not have occurred. First, we thank Dr. Lane Rawlins, President of Memphis State University, and Dr. Victor Feisal, Vice-President of Academic Affairs at Memphis State University, for their support of this conference. Additionally, we extend our appreciation to Dr. Claude Lenfant, Director of the NHLBI, for his continued support of smoking research. We also thank Dr. Robin Hill of the NHLBI and Ms. Faye Wright of Memphis State University for their invaluable assistance in setting up the conference. We thank the contributors of this report. Their input made this a truly memorable and enjoyable experience. Finally, we thank Servier Laboratories and Lily Research Laboratories for their financial assistance.
Understanding the Relations Between Smoking and Body Weight and Their Importance to Smoking Cessation and Relapse Robert C. Klesges Center for Applied Psychological Research Memphis State University
Sally A. Shumaker
This document is copyrighted by the American Psychological Association or one of its allied publishers. This article is intended solely for the personal use of the individual user and is not to be disseminated broadly.
Bowman Gray School of Medicine Wake Forest University
A conference on smoking and body weight was conducted September 10 to 13,1990, at Memphis State University, Memphis, Tennessee. Approximately 40 participants and 100 interested professionals were involved in the 4-day conference in which the primary goal was to bring together a multidisciplinary team of scientists to consider the complex relations between smoking and body weight and to suggest the most appropriate research methods for investigating these relations. Co-sponsored by Memphis State University and the National Heart, Lung, and Blood Institute (NHLBI) of the National Institutes of Health, the conference included a series of theory-based and empirically based presentations by leading experts in the fields of smoking behavior, diet and nutrition, weight control, exercise, and energy expenditure. Formal presentations were made—see abstracts appearing in this supplement—and working groups composed of representatives from the various relevant disciplines discussed, in detail, current theoretical models and state-of-the-art methods to guide research on the relations between smoking and body weight and to address the implications of these relations to smoking initiation, cessation, and relapse. These groups met throughout the conference, and the results of their deliberations form the basis for this Health Psychology supplement.
WHY STUDY RELATIONS BETWEEN SMOKING AND BODY WEIGHT? Most people are aware that smoking is closely related to cancer, emphysema, and heart disease. However, the magnitude of the health problems associated with smoking is often not fully appreciated. More than 40,000 studies have documented the relation between smoking and health, and close to 500,000 people die of smoking in the United States each year (U.S. Department of Health and Human Services [USDHHS], 1990). A recent 10-year follow-up study of more than 361,000 participants in the Multiple Risk Factor Intervention Trial (MRFIT) revealed that approximately half of all deaths were associated with cigarette smoking. Although the incidence rate of cigarette smoking in the United States is declining, the decrease in smoking has been much greater in men than in women (Pierce, Fiore, Novotny, Hatziandreu, & Davis, 1989). It is estimated that the number of female smokers will equal the number of male smokers by 1995 (Pierce et al., 1989). With the increased relative number of women smokers comes increased Address all correspondence and requests for reprints for this supplement to Robert C. Klesges, Department of Psychology, Center for Applied Psychological Research, Memphis State University, Memphis, TN 38152.
smoking-related disease. For example, lung cancer is now more prevalent than breast cancer in women (American Cancer Society, 1990). Although the reasons for the increased relative incidence of smoking among women are not known, one contributory factor appears to be the widespread belief that smoking controls body weight (Pirie, Murray, & Leupker, 1991). Indeed, recent epidemiological studies have confirmed that cigarette smokers weigh less than comparable-age nonsmokers (Gordon, Kannel, Dawber, & McGee, 1975; D. R. Jacobs & Gottenborg, 1981), that individuals who start smoking lose weight (Lund-Larsen & Tretli, 1982), and that many smokers who quit smoking gain weight (Coates & Li, 1983; Hall, Ginsberg, & R. J. Jones, 1986; Manley & Boland, 1983; Noppa & Bengtsson, 1980; Schoenenberger, 1982). Reviews of the relation between smoking cessation and weight gain have estimated the average weight gain following smoking cessation to be between 4.5 and 7.5 lb (R. C. Klesges, Meyers, L. M. Klesges, & LaVasque, 1989; USDHHS, 1990). However, recent studies have suggested that certain groups of individuals may be at risk for large amounts of weight gain following cessation. Based on a longitudinal analysis of 9,332 participants in the First National Health and Nutrition Examination Survey (NHANES 1), average weight gain among women who quit smoking was greater (8.4 lb) than among men who quit smoking (6.2 lb; Williamson et al., 1991). Major weight gain (defined as a weight gain of more than 28.6 lb) occurred in 13.4% of the women and in 9.8% of the men who quit smoking. Blacks, people under the age of 55, people smoking more cigarettes per day, and people who were less obese at baseline were at most risk for large weight gains (Gerace, Hollis, Ockene, & Svendsen, 1991; Williamson et al., 1991). The weight gain following smoking cessation may produce undesirable health problems, although these are probably modest given the large health benefits of quitting smoking (Kuller et al., 1991). For example, a recent study of 3,470 participants of MRFIT revealed that the onset of hypertension was higher in those who quit smoking (35%) than in those who continued to smoke (27%; Gerace et al., 1991). Weight gain following cessation was largely responsible for this increased incidence of hypertension in quitters. Given the large body of literature that supports a link between smoking cessation and weight gain, it may be surprising to learn that there is little known regarding the reasons (mechanisms) for postcessation weight gain. A recent review (USDHHS, 1990) summarized the available data on the predictors of postcessation weight gain. In the area of dietary intake, of 8 studies reported, only 2 provided strong support for dietary changes following cessation, 4 provided qualified support for dietary changes following cessation (e.g., changes in nutrients but no changes in total dietary intake), and
This document is copyrighted by the American Psychological Association or one of its allied publishers. This article is intended solely for the personal use of the individual user and is not to be disseminated broadly.
2
KLESGES AND SHUMAKER
2 reported no changes in dietary intake following cessation (USDHHS, 1990). Of 14 studies assessing the metabolic contribution of smoking, only 8 (57%) found either acute or chronic increases in metabolic rate following smoking or decreases in metabolic rate after smoking cessation (USDHHS, 1990). The one area in which consistent findings emerge is the evidence that physical activity does not appear to change following smoking cessation. However, the number of studies evaluating physical activity has been limited (USDHHS, 1990). Although those who quit smoking are at higher risk for a major weight gain relative to those who continue to smoke (USDHHS, 1990), the average weight gain for the typical smoker is minimal from a health standpoint (4.5 to 7.5 lb; R. C. Klesges, Meyers, L. M. Klesges, & LaVasque, 1989; USDHHS, 1990). Yet, concern regarding postcessation weight gain appears to be a powerful motivator for continued smoking (R. C. Klesges & L. M. Klesges, 1988). A recent survey of 6,711 young adults (Pirie et al., 1991) indicated that substantially more female smokers than male smokers reported concern about weight gain if they quit smoking (58% vs. 26%). Regular smokers are much more concerned about body weight than ex-smokers, and smokers not intending to quit are much more likely to be concerned about weight gain than smokers intending to quit (R. C. Klesges, Somes et al., 1988; Weekley, R. C. Klesges, & Reylea, in press). Concerns about postcessation weight gain appeared to predict cessation in a recent stop-smoking program (R. C. Klesges, K. Brown et al., 1988). Finally, in the area of smoking initiation, weight-control beliefs related to smoking reliably predicted adolescent smokers versus those who tried smoking but later quit (Camp, R. C. Klesges, & Reylea, in press). These weight-control beliefs were predictive even after controlling for other strong predictors of smoking onset (e.g., number of peers who smoke; Camp et al., in press). It appears that concerns or beliefs regarding postcessation weight gain are more important than actual weight gain and may be associated with continued maintenance of smoking (Hall et al., 1986).
SETTING A NATIONAL AGENDA Given the important relation between smoking and body weight, Memphis State University and the NHLBI organized the 1990 conference with two major goals in mind: (a) to summarize what is known regarding the relation between smoking and body weight and (b) to set an agenda for future research. Other than knowing that people gain weight following smoking cessation (and that smokers are concerned about this), surprisingly little is known. For example, we need to know more about who is likely to gain the most weight following smoking cessation. We also need to better understand the cause(s) of postcessation weight gain. Given that the determinants of weight gain in nonsmokers are different in males versus females (R. C. Klesges, L. M. Klesges, Haddock, & Eck, 1992), one might expect different relative dietary versus metabolic contributions of postcessation weight gain as a function of gender and, perhaps, race, age, and the number of cigarettes smoked per day. We also need better information on who is smoking for weight control and how strongly weight control motivates smoking behavior. Gender appears to be an important predictor of concerns related to postcessation weight gain (R. C. Klesges & L. M. Klesges, 1988; Pirie et al., 1991), but other factors may also be important. For
example, in the Camp et al. (in press) study of smoking initiation, smoking for weight control was exclusively observed in White Americans—not a single Black American smoker reported smoking for weight control. Given the degree to which beliefs and, to some extent, misconceptions about the amount of weight gain appear to influence smoking maintenance, we need to educate smokers about the small actual weight-gain risk associated with cessation. Finally, and perhaps most important, we need to develop and evaluate interventions to reduce postcessation weight gain for those people at risk of major weight gain following smoking cessation and for those for whom a small weight gain (e.g., people with diabetes) may place them at medical risk. We also need to develop interventions either to reduce postcessation weight gain or to address concerns related to postcessation weight gain for those unwilling to quit smoking even if a small weight gain is observed.
ORGANIZATION OF THE SUPPLEMENT The articles that follow are the end result of a year of planning; 4 grueling days of working groups, writing sessions, and presentations; and almost a year of writing, editing, and consensus gathering. The initial papers resulted from the deliberations of the working groups. The Task Force 1 report, "Mechanisms Relevant to the Relation Between Cigarette Smoking and Body Weight," details the mechanisms by which smoking may have an effect on body weight. The Task Force 2 report, "Methods of Assessment: Strategies for Research," includes a review of the methodological and measurement issues inherent in the study of the relation between smoking and body weight, as well as the strengths and weaknesses of procedures for the assessment of energy balance (i.e., dietary intake, physical activity, and metabolic rate), and smoking in both animal and human models. The Task Force 3 report, "Implications With Respect to Prevention and Interventions," reviews prevention and intervention strategies for the treatment of weight gain following smoking cessation. Following these reports is Neil Grunberg's article, "Cigarette Smoking and Body Weight: A Personal Journey Through a Complex Field," in which he draws on his own experiences to describe the various disciplines needed to conduct research on the relation between smoking and body weight. Evan Pattishal then provides a synthesis of the conference in "Smoking and Body Weight: Reactions and Perspectives." Following Pettishal's article is a collection of the formal presentations (abstracts) made at the conference and the discussants' commentaries. Last, the references at the end of the supplement represent a comprehensive bibliography of the smoking and body weight literature. This supplement should provide the impetus for research in the area of smoking and body weight that incorporates the necessary multidisciplinary approach coupled with the most current theoretical models and research methods. Perhaps more important, this contribution highlights the importance of regular communication among scientists working in related but different fields of research. Many of the outstanding and well-known findings, methodologies, and investigators within one area of inquiry may be unknown to investigators who study different problems within the same discipline or the same question from the perspectives of different disciplines. As technologies have grown, as the number of scientists has increased, and as the number of specialty journals has proliferated, the need for
RELATIONS BETWEEN SMOKING AND BODY WEIGHT
meaningful communication through working conferences and multidisciplinary, problem-oriented research has increased. ACKNOWLEDGMENTS
This document is copyrighted by the American Psychological Association or one of its allied publishers. This article is intended solely for the personal use of the individual user and is not to be disseminated broadly.
The introduction to this supplement was supported by National Heart, Lung, and Blood Institute (NHLBI) Grants HL-45057 and HL-46352 to Robert C. Klesges. Robert C. Klesges and Sally A. Shumaker contributed equally to preparation of this supplement. We thank a few individuals without whom this conference would
3
not have occurred. First, we thank Dr. Lane Rawlins, President of Memphis State University, and Dr. Victor Feisal, Vice-President of Academic Affairs at Memphis State University, for their support of this conference. Additionally, we extend our appreciation to Dr. Claude Lenfant, Director of the NHLBI, for his continued support of smoking research. We also thank Dr. Robin Hill of the NHLBI and Ms. Faye Wright of Memphis State University for their invaluable assistance in setting up the conference. We thank the contributors of this report. Their input made this a truly memorable and enjoyable experience. Finally, we thank Servier Laboratories and Lily Research Laboratories for their financial assistance.
