This study extends previous findings regarding the association between peer relationships and weight control (e.g. (Ball & Crawford, 2006
; Christakis & Fowler, 2007
)) to show that an individual’s general perception of others’ body size may influence progress and success in a structured weight loss and weight loss maintenance program. Results were specific for EA women, suggesting that cultural factors affect environmental influences on body weight regulation. These observations have important implications for both obesity research and clinical practice.
The mechanism underlying the association between the perception of others’ body size and success with weight loss may have been cognitive restraint. We observed that when cognitive restraint was added to the regression model, the association between perception of others’ body size and percent body fat one year after the intervention was weakened. This may indicate that women who perceived others as overweight may have been less willing or able to restrict their own food intake, and thus were more likely to regain body fat. Due to the correlational nature of this data, future research will be important to ascertain whether food intake patterns are indeed different for women who perceive others as being overweight versus those who perceive others as normal weight.
If differences in dietary restraint do underlie the relationship between perception of others’ size and weight gain, this may indicate an important role for social cues on appropriate meal size. For example, previous research has found that people are more likely to overeat if others sharing the meal are themselves overeating (Conger, Conger, Costanzo, Wright, & Matter, 1980
; Herman, Roth, & Polivy, 2003
), and studies of adults and children have found that overweight people will eat more if their meal companion is also overweight (de Luca & Spigelman, 1979
; Salvy et al., 2007
). It is plausible that this social facilitation effect during meals might extend to a general obesity-promoting lifestyle. In this way, women who perceive others as being overweight may view larger body sizes as the “norm”, feel less social pressure to be lean, and therefore have less dietary restraint. It is also possible that the perception of others’ body size served as a proxy measure for aspects of the environment that affect weight control, analogous to what has been observed for drug addiction (Drummond, 2000
). In both cases, environmental cues may trigger deleterious behavior.
We observed a race difference in the relationship between perception of others’ body size and percent fat at one year follow-up, such that this association was observed only within EA women. This race difference may reflect cultural factors that affect behavioral regulation of body weight. Within EA women, drive for thinness is reported to affect weight loss behavior (Ard, Greene, Malpede, & Jefferson, 2007
), while among AA women, ability to lose weight is limited by lack of social support (Baturka, Hornsby, & Schorling, 2000
), a cultural belief in self-acceptance regardless of body size (Baturka et al., 2000
), and practical issues such as food preparation and education regarding healthy diets (Ard et al., 2007
). A race difference in drive for thinness is supported by the fact that in this study, EA women reported a greater discrepancy between their own body size and that of others, than did AA women. Results of the current study therefore, support the possibility that the perceived size of others may be a less important motivator for weight loss among AA women as compared to EA women.
An important strength of this study was to follow the women through both an investigator-managed weight loss program, insuring the participants achieved the goal weight, and then through the following year, when many of the women regained some weight. In doing so, we were able to investigate the effect of body size perception on both weight loss and weight maintenance. This study was also strengthened by the use of DXA to measure body fat at each time point, as opposed to simple body weight and indirect measures of body composition. Limitations of this study however, include the relatively small and homogenous sample population, inhibiting the generalizability of these results, and the fact that the primary analyses were correlational. Future studies will be important to determine who serves as a passive influence toward an individual’s weight control, and the mechanism through which this influence transpires into weight gain or maintenance.
The results of this study implicate a potential role for social perception on body weight regulation by suggesting that the mere perception of overweight as common in the general society may itself sabotage weight loss and weight maintenance success. The implication of this finding for public health is that the increasing prevalence of obesity may be facilitating weight gain amongst individuals, thereby exacerbating the obesity epidemic. A further implication for obesity researchers is to consider the importance of the social and cultural environment when designing weight loss interventions. For some populations, such as EA women, a successful intervention may need to ascertain the extent to which each individual perceives overweight body sizes as normal, and work with participants to counteract the potentially detrimental behavioral consequences of this perception.