Patterns and predictors of weight change among women

Adults are getting heavier; however, there are few longitudinal data to provide information on factors associated with patterns of weight change within individuals during adulthood. The purpose of the present research was identifying relatively stable psychosocial, behavioral or contextual factors that have been consistently associated with weight status among adults, and to assess whether these factors predict weight change over time. Participants included non-Hispanic white women in central Pennsylvania recruited as part of a longitudinal study. Data were collected across an 8-year period, with 2-year intervals between assessments. Height and weight were measured in triplicate. Dietary restraint and disinhibition were assessed using the Eating Inventory. Global reports of dieting and specific weight control strategies were assessed by the Weight Loss Behavior Scale. Energy density was calculated from energy content of all foods (excluding beverages) at each occasion from three 24-hour recalls. A series of mixed effect models were used to examine the influence of several factors on weight change over time. Results revealed that (1) self reported dieting was associated with weight gain; (2) increases in dietary restraint may be protective against long-term weight maintenance by moderating the positive association between dietary disinhibition and weight gain among dieters; (3) assessing patterns of use of specific weight control strategies discriminated among women using different approaches to control weight; (4) different patterns of weight control use were predictive of differences in weight gain: use of healthy plus unhealthy weight control strategies was associated with greater weight gain; whereas only using healthy weight control strategies may promote weight maintenance; and (5) decreasing dietary energy density by increasing intake of water rich foods such as fruits and vegetables may be an effective weight maintenance strategy. Data indicate that, on average, women gained approximately 0.6 kg per year; however, several modifiable factors were identified that may promote weight maintenance. Results from all three studies have important implications for the development of recommendations and intervention programs promoting weight maintenance.