Beans Improve Satiety to an Effect that Is Not Significantly Different from Beef in Older Adults: A Randomized, Crossover Trial.

Abstract

Background: Beans are a candidate food for increasing satiety due to their protein and dietary fiber content. Beef is a common animal protein that can increase satiety due to its protein content, which is higher than beans but does not contain dietary fiber. Dietary guidance encourages higher intake of plant-based protein foods and warrants satiety studies that compare plant and animal protein foods, which could particularly benefit the rapidly growing population segment of older adults.

Objectives: To compare the effects of 2 bean varieties and beef consumed within a breakfast tortilla on satiety, food intake, and 24-h energy intake in older adults.

Methods: Older adults [n = 35, age 72.4 ± 6.66 y, BMI (in kg/m²) 25.1 ± 3.25] consumed 3 breakfast tortilla test meals containing 1 serving of black beans (135 g), red kidney beans (135 g), or beef (80 g) in a randomized, crossover design. Participants rated their appetite sensations on periodic visual analogue scales, food intake was measured at an ad libitum pizza lunch meal, and 24-h energy intake was measured using weighed food records. Appetite sensation area under the curves (AUCs) were compared between treatments using repeated-measures analysis of covariance, and food intake and 24-h energy intake were compared using repeated-measures analysis of variance.

Results: Fullness and satisfaction were significantly increased, while hunger, desire to eat, and prospective food consumption were significantly decreased, following consumption of the black bean, red kidney bean, and beef test meals. Appetite sensation AUCs, ad libitum pizza intake, and 24-h energy intake did not significantly differ between the test meals.

Conclusions: These results demonstrate that beans improve satiety to an extent that is not significantly different from beef in older adults, thereby supporting the role of beans as a nutrient-dense source of protein and dietary fiber as part of a satisfying meal for older adults. This trial was registered at clinicaltrials.gov as NCT05499819.