Consuming 30g of Protein at Each of 3 Meals Daily Improves Diet Satisfaction and Promotes Eating Behaviors That Support Weight Loss in Women Consuming an Energy Restricted Diet

OBJECTIVES: The objective was to test the efficacy of two patterns of daily protein consumption to promote diet satisfaction and eating behaviors that support weight loss when consuming an energy restricted diet in women. METHODS: A randomized parallel study consisted of 8 weeks of controlled energy restriction (20% reduction; all foods provided) followed by 8 weeks of self-choice eating during which participants were coached to maintain a similar dietary pattern and energy restriction when choosing, buying, and consuming their own foods. The diets differed only in the daily distribution of dietary protein consumption. For one group (EVEN; n = 18; age = 29 ± 8 years; BMI = 35 ± 3 kg/m(2)) dietary protein was evenly distributed among breakfast, lunch, and dinner (30 g at each meal). For the other group (SKEWED; n = 19; age = 35 ± 7 years; BMI = 36 ± 4 kg/m(2)) dietary protein distribution was skewed with 10g at breakfast, 15g at lunch, and 65g at dinner. At each study visit (weeks 0, 8, 16) subjects completed eating behavior questionnaires and the relative reinforcing value (RRV) of energy-dense snack foods was assessed 4 hours after lunch using a computer choice paradigm. Meals provided for each study visit were consistent with the subject's assigned dietary protein distribution pattern. Diet adherence and satisfaction were reported weekly during the self-choice phase. RESULTS: Compared to the SKEWED group, RRV in the EVEN group was lower at all time points (p = .019). Both groups reported adhering to their assigned dietary protein distribution pattern on average 6 days each week. However, subjects in the EVEN group were more satisfied with their diet (p = .004), happier with their food choices (p = .008) and tended to be less distracted or bothered by hunger (p = .07) compared to the SKEWED group. During the self-choice phase, intrinsic motivation (p = .0006), body-food choice congruence (p < .0001), and attitude to self-regulation (p < .0001) increased in the EVEN group with no changes in the SKEWED group. CONCLUSIONS: In conclusion, evenly distributing dietary protein throughout the day resulted in women being more satisfied with their dietary choices and improved eating behaviors that support better adherence to a weight loss diet. These preliminary results indicate that eating 30g of protein at each meal is advantageous to women when trying to lose weight. FUNDING SOURCES: USDA ARS and the ND Beef Commission.