(LB03-04-24) Evenly Distributing Daily Dietary Protein Across Three Meals During Weight Loss Reduces Women’s Snack Food Reinforcement and Intake of Energy-Dense Snack Foods

Objectives: High-protein, energy-restricted diets are beneficial for weight loss and weight maintenance; however, it is not yet known whether consuming a modest amount of protein in a balanced distribution throughout the day reduces the reinforcing value of energy-dense snack foods or reduces energy intake when presented with those foods. We aimed to assess (1) the efficacy of two patterns of protein distribution during weight loss on the reinforcing value of energy-dense snack foods relative to a reinforcing nonfood alternative (RRV) and (2) energy intake when presented with snack foods.

Methods: Healthy women (n = 43) with a body mass index 28-45 kg/m² completed a 16-week randomized parallel study testing two patterns of daily protein intake (even distribution across three meals vs. a skewed distribution with most protein consumed at the evening meal). RRV was assessed at baseline, week 8, and week 16 using an operant responding computer task two hours after a meal that corresponded with participants’ protein distribution pattern (EVEN 30 g protein lunch, SKEWED 15g protein lunch). Data were analyzed using linear mixed models and are presented as differences in least squares means ± standard error. Statistical significance was set at p < 0.05.

Results: There was a main effect of group for RRV of energy-dense snack foods (p = 0.0476), with RRV in the EVEN group, 0.44 ± 0.04, being lower than in the SKEWED group, 0.55 ± 0.04. While there was no difference between groups in the amount (grams) of snacks earned and thus presented to the women (p = 0.2338), the amount of snacks consumed in the EVEN group was less than in the SKEWED group, 44.3 ± 5.2 g vs 62.0 ± 5.1 g (p = 0.0197). Correspondingly, the EVEN group consumed less energy from the snack foods than the SKEWED group, 218.6 ± 25.1 kcal vs 301.3 ± 24.6 kcal (p = 0.0238). No time effects or group by time interactions were observed.

Conclusions: Lower RRV and consumption of energy-dense snack foods in the EVEN group suggest greater satiety following a lunch with 30 g of protein compared to 15 g as part of a dietary protein intake pattern with an even distribution across three meals. These results may contribute to dietary guidance provided to women in support of weight loss efforts.

Funding Sources: The Agricultural Research Services of the United States Department of Agriculture and the North Dakota Beef Commission funded this research.