(P15-011-24) Incorporation of Dry Edible Beans to a High-Fat Diet Does Not Affect Body Composition and Bone Structural Parameters in Obese Mice

Objectives: The 2020 USDA Dietary Guidelines for Americans recommend weekly intake up to 1.5 cups of dry edible beans (pulses) as part of healthy U.S.-style dietary pattern. Pulses contain great amounts of antioxidant bioactive components and fiber that have beneficial effects on bone. This study investigated whether incorporation of dried pulses to a high-fat diet improves bone metabolism in obese mice. We hypothesized that addition of either whole or milled pulses into a high-fat diet mitigates bone deterioration in obese mice.

Methods: Male C57BL/6 mice at 4-week-old were randomly assigned to four treatment groups (n=23-24/group) and one of the following diets ad libitum for 12 weeks: a normal-fat (NF; 4.1 kcal/g and 16% energy as fat), a high-fat diet (HF; 4.9 kcal/g and 48% energy as fat), or a HF diet containing either cooked whole (HFWB) or milled (HFMB) pulses at 15% w/w. Data were analyzed using one-way ANOVA followed by Tukey-Kramer post hoc contrasts.

Results: Food intake by animals fed either the HF, HFWB, or HFMB was less than that by those fed the NF (P < 0.05), but total energy intake was similar (P > 0.05), due to the higher energy content of the three HF diets. Mice fed the HF, HFWB, or HFMB had greater body weight and fat mass than those fed the NF. Mice fed the HFWB or HFMB but not the HF had higher lean mass than those fed the NF. Mice fed the HF, HFWB, or HFMB had 23%, 14%, and 12% lower tibial bone volume/total volume (BV/TV, P < 0.05), respectively, than those on the NF. Mice fed the HF but not the HFWB or HFMB had lower BV/TV in 2^nd lumbar vertebrae than those fed the NF. There were no differences in body weight, fat mass, lean mass, or any of bone structural parameters among HF, HFWB, and HFMB groups (P > 0.05).

Conclusions: These data indicate that obesity induced by a high-fat diet increases fat mass and decreases bone mass and incorporation of pulses into a high-fat diet has only minimal beneficial effect on lean body mass and bone structure in obese mice.

Funding Sources: Agricultural Research Service of the United States Department of Agriculture, #3062-51000-056-00D