Objective: The purpose of this study was to examine whether the diet and exercise behaviors of successful weight losers entering the National Weight Control Registry (NWCR) have changed between 1995 and 2003.
Research method and procedures: Participants (N = 2708) were members of the NWCR who enrolled in intermittent years since 1995. Participants had lost an average of 33.1 kg and maintained a 13.6-kg loss for 5.8 years before enrollment. Evaluations of diet and physical activity were conducted at entry into the NWCR and prospectively over 1 year.
Results: From 1995 to 2003, the daily percentage of calories from fat increased from 23.8% to 29.4%, saturated fat intake increased from 12.3 to 154.0 g/d, and calories from carbohydrate decreased from 56.0% to 49.3% (p < 0.0001). The proportion consuming <90 grams of carbohydrate (considered a low-carbohydrate diet) increased from 5.9% to 17.1% (p = 0.0001). Physical activity was elevated in 1995 (mean = 3316 kcal/wk) but comparable in all other years (mean = 2620 kcal/wk). Stepwise regression collapsing across cohorts indicated that weight regain over 1 year was related to higher levels of caloric intake, fast food consumption, and fat intake and lower levels of physical activity (p < 0.03).
Discussion: The macronutrient composition of the diet of NWCR members has shifted over the past decade. Still, only a minority consumes a low-carbohydrate diet. Despite changes in the diet over time, the variables associated with long-term maintenance of weight loss were the same: continued consumption of a low-calorie diet with moderate fat intake, limited fast food, and high levels of physical activity.