(P13-009-25) Impact of Daily Protein and Energy Intake Distribution Patterns on Substrate Utilization in Adults As Measured via Room Calorimetry

Objectives: Evenly distributing protein throughout the day can positively influence metabolism. However, no study has examined the role of energy distribution. We sought to determine the effect of both protein and energy intake patterns on metabolism.

Methods: Adults (n=32; age: 28 ± 11 y; BMI: 25 ± 5 kg/m²; daily energy intake: 2652 ± 583 kcal) completed this randomized, cross-over study. Females (n=15) were tested on cycle days 17-19. Participants consumed a 3-day lead-in diet aligned with the protein intake pattern for the subsequent study visit. Study diets consisted of 90g/day of high-quality protein but differed in distribution patterns: 1) evenly across meals (30g/meal) and 2) conventional eating pattern of US adult population (breakfast: 10g, lunch: 15g, supper: 65g). On day 1 of each study visit participants consumed a typical energy intake pattern (23%, 34%, 43% of estimated energy requirements at breakfast, lunch, supper, respectively) and on day 2 the same amount of energy was distributed evenly across all meals. Dietary fat was held at 33 ± 1% while carbohydrate was adjusted to meet individual energy needs. Data were analyzed in RStudio and presented as least square mean ± SEM.

Results: Evenly distributing energy resulted in a greater thermic effect of food (TEF) compared to skewing energy intake (p=.015; 7.4 ± 0.4%, 6.6 ± 0.4% of energy intake, respectively). Fat oxidation was greater when energy intake was skewed compared to being evenly distributed (p=.011; 82 ± 8g, 71 ± 8g, respectively). Carbohydrate oxidation was greater when evenly distributing energy intake compared to being skewed (p=.022; 269 ± 24g, 249 ± 24, respectively) and was greater in men compared to women (p=.013; 309 ± 22g, 209 ± 36, respectively). There was also a sex by protein distribution pattern interaction (p=.028) with carbohydrate oxidation being greater in men when consuming the even compared to the skewed protein distribution pattern (p=.047; 324 ± 23g, 293 ± 23, respectively) with no difference in women. Neither the protein nor energy distribution pattern impacted protein oxidation.

Conclusions: These findings demonstrate that the distribution of energy throughout the day may play a more important role in energy metabolism and substrate oxidation than the macronutrient composition of the meals.

Funding Sources: USDA ARS #3062-10700-001-000D