Background: Diets containing beans have been associated with a lower risk of obesity and overweight in several dietary surveys. These results suggest a benefit might be derived from beans and other pulses, possibly due to improved satiety or satiation and therefore lowering energy intake. Such a hypothesis has not been tested.
Objectives: To investigate the effect of processing, recipe, and pulse variety on short-term food intake (FI), subjective appetite, and glycemic response after pulse consumption in healthy young men.
Design: Three experiments were conducted. In a randomized repeated-measures design, young men aged 18-35 years with a body mass index of 20-25 kg/m(2) were fed the test treatments. In experiment 1 (n = 14), navy beans canned in Canada or in the United Kingdom were compared with homemade navy beans and 300 ml of glucose drink, each containing 50 g of available carbohydrate. In experiment 2 (n = 14), canned navy beans in tomato sauce, maple style, with pork and molasses, and homemade navy beans with pork and molasses were compared with white bread, each containing 50 g of available carbohydrate. In experiment 3 (n = 15), 4 equicaloric (300-kcal) treatments of pulses were compared with both a white bread and water control. Blood glucose and subjective appetite were measured from immediately before consumption of the treatment to 120 minutes later when FI from a pizza meal was measured.
Results: All caloric treatments decreased subjective appetite. In no experiment did any pulse treatment lower FI at 120 minutes compared with white bread or result in lower cumulative FI (sum of calories from treatment and pizza meal) compared with either 50 g of available carbohydrate as a glucose drink (experiment 1) or from white bread (experiment 2) or compared with equal food energy from white bread (experiment 3). Glycemic response to navy beans was affected by recipe, but not processing, and as with the other pulses, it was lower than with white bread. An inverse relationship was observed between glycemic response and both subjective appetite and FI at 120 minutes in experiment 3 (r = -0.4, p = 0.001) but not in experiments 1 (r = 0.1, p = 0.62) and 2 (r = 0.2, p = 0.10).
Conclusion: The short-term effect of pulse consumption on subjective appetite and FI at a meal 120 minutes later and in cumulative food intake was determined primarily by energy content and was little influenced by composition, processing, recipe, or variety. Thus, the epidemiological associations between frequent pulse consumption and lower risk of obesity and overweight are not explained by short-term effect of pulses on satiety and FI.