Weight Loss, but Not Dairy Composition of Diet, Moderately Affects Satiety and Postprandial Gut Hormone Patterns in Adults

Abstract

ABSTRACT Background Inclusion of dairy in diet patterns has been shown to have mixed effects on weight loss. A prevailing hypothesis is that dairy improves weight loss by influencing endocrine systems associated with satiety and food intake regulation. Objectives The objective of the current study was to evaluate the effect of weight loss with or without adequate dietary dairy on subjective and objective appetitive measures. Methods Men and women who were habitual low dairy consumers (n = 65, 20–50 y) participated in a 12-wk randomized controlled feeding weight loss trial. During the 12-wk intervention, a low-dairy (<1 serving dairy/d) was compared with an adequate-dairy (3–4 servings dairy/d) diet, both with a 500-kcal deficit/d. Test days, before and at the end of the intervention, began with 2 fasting blood draws and visual analog scale (VAS) measures, followed by a standard breakfast (25% of prescribed restricted calories), 5 postbreakfast blood draws and VASs, a standard lunch (40% of restricted energy amount), and 12 postlunch blood draws and VASs. Blood samples were used for satiety hormone measurements. On a separate day when matching standard meals were consumed, an ad libitum buffet meal was provided as dinner, at a self-selected time. Meal duration and intermeal interval were recorded. Results Weight loss (−6.1 kg), irrespective of dairy, resulted in reduced fasting insulin (−20%) and leptin (−25%), and increased fasting acylated ghrelin (+25%) and VAS desire to eat (+18%) (P < 0.05). There were no effects of dairy on objective or subjective satiety measures. Weight loss marginally reduced the intermeal interval (289 min compared with 276 min, P = 0.059) between lunch and the ad libitum buffet. Conclusions These results do not support the hypothesis that inclusion of dairy in long-term dietary patterns influences appetite during weight loss. Weight loss per se has a modest impact on select systems that regulate hunger and satiety. This trial was registered at clinicaltrials.gov as NCT00858312.