(P28-08-26) Effects of a Long-Term High-Fiber Legume Diet on Body Weight in Adults With Overweight or Obesity

Objectives: We evaluated the effect of a long-term, high-fiber diet featuring legumes on changes in body weight among adults with overweight or obesity.

Methods: Sixty adults were enrolled in a 6-month, double-blind, semi-controlled clinical feeding trial. Following a 7-day run-in period, adults were randomized to either a high-fiber legume diet (HLD) or a control diet with protein replaced as lean meat. Participants received pre-portioned meals daily (2 meals/d during months 1-3 and 1 meal/d during months 4-6). Diets were matched for total energy and macronutrient composition, with each HLD meal providing an additional 25 grams of dietary fiber. Both intervention groups received standardized weight-loss counseling delivered by a registered dietitian. Body weight was measured using in-person weighing at baseline and 6-months. Linear mixed effect models were used to compare differences in absolute and percent weight change (%∆) between diets. We additionally evaluated for effect modification by sex.

Results: A total of 56 adults (64% female, mean age ± SD: 59.9 ± 7.6 yrs; mean Body Mass Index: 31.7 ± 4.1 kg/m²) completed the intervention. After 6-months, both diets were effective at reducing body weight (HLD: -3.77 ± 3.2 kg, -4.43 ± 3.82 %∆; Control: -4.86 ± 3.9 kg, -5.38 ± 4.4 %∆). Males lost 1.6 kg (1.0 %∆) more weight compared to females. Compared to the control diet, the difference in weight at 6-months was similar for the HLD (1.09 95% CI: -0.85, 3.03 kg; 0.95 95% CI: -1.27, 3.17 %∆). Effects of HDL on weight change were similar between males (2.41 95% CI: -1.44, 6.26 kg, 1.92 95%CI: -2.06, 5.89 %∆) and females (0.48 95% CI: -1.85, 2.81 kg, -0.50 95% CI: -2.41, 0.34 %∆) (P-interact > 0.05).

Conclusions: A long-term, high-fiber diet featuring legumes was effective in supporting weight-loss comparable to a control diet featuring lean meat. These findings suggest the combination of structured feeding and weight-loss counseling are viable tools for promoting weight loss in adults with elevated BMI.

Funding Sources: NIH/NCI R011CA245063-01A1; Emory University Hospital Georgia CTSA Clinical Research Center