(P29-028-24) Adherence to a DGA-Like Diet Confers a Wide Range of Responses in Body Composition in Diversity Outbred Mice

Objectives: The Dietary Guidelines for Americans (DGA) were developed to provide guidance on what Americans should eat in order to meet nutritional needs and prevent diseases such as obesity. To investigate whether adhering to the DGA’s recommendations will result in improved health outcomes, we fed a genetically diverse population of Diversity Outbred (DO) mice either a typical Westernized diet or a diet formulated to mimic the dietary recommendations of the DGA, and then examined the effects of sex and diet on body composition, revealing great variation in individual response to both diet treatments.

Methods: We obtained 200 DO mice (f = 100, m = 100), and half of the mice of each sex were fed either a Western or Mediterranean diet at 6 weeks of age. After 11 weeks of administering these diets, body composition was measured using NMR. Body fat % (BF%) was calculated by dividing fat mass by total body weight (BW) with results shown as mean ± standard error. Student’s t test was used to test for significance of differences in mean BW and BF% between groups as indicated.

Results: After 11 weeks of feeding the DO mice either the Western (W) or Mediterranean (M) diet, we found that sex significantly influenced BW (f = 32.9 ± 0.7 g, m = 43.5 ± 0.6 g; p < 2.2 x 10^-16) but not BF% (f = 26.7 ± 1.1%, m = 24.1 ± 0.7%; p > 0.05) in our preliminary results. In terms of diet effects, neither BW (W = 38.7 ± 0.8 g, M = 37.7 ± 0.9 g) nor BF% (W = 25.12 ± 0.92%, M = 25.7 ± 0.9%) significantly differed by diet. However, individual responses to diet were highly heterogeneous for both BW (W: standard deviation [sd] = 8.5 g, min = 19.7 g, max = 55.1; M: sd = 9.1 g, min = 20.2 g, max = 54.9 g) and BF% (W: sd = 9.1%, min = 3.1%, max = 44.2%; M: sd = 9.8%, min = 5.3%, max = 49.5%), demonstrating the necessity of personalized approaches for improving health outcomes.

Conclusions: The great heterogeneity in BW and BF% in the DO mice highlights the complexity of individuals’ unique responses to both “healthy” and “unhealthy” diets, as well as the need to utilize precision nutrition for increased efficacy of dietary alterations to improve health. Studying the effect of these diets on other biomarkers of disease will further elucidate which factors are more sensitive to dietary interventions.

Funding Sources: USDA