"Eat dry beans, split peas, lentils and soya regularly": a food-based dietary guideline

Abstract

The objective of this paper is to review recent scientific evidence to support the food-based dietary guideline (FBDG): “Eat dry beans, split peas, lentils and soya regularly”. In this review, legumes are synonymous with the term “pulses”, while soy beans are classified as “oilseeds”. The FBDG was originally introduced to address both under- and overnutrition in South Africa. The nutrient and non-nutrient content, results of recent epidemiological and intervention studies on health effects, recommended intakes and barriers to consumption are briefly reviewed. Legumes are rich and economical sources of good-quality protein, slow-release carbohydrates, dietary fibre (non-starch polysaccharides), various vitamins and minerals and non-nutritive components which may have several beneficial health effects. Pulses have a low energy, fat and sodium content. Therefore, legumes contribute to dietary adequacy, while protecting against noncommunicable diseases through many mechanisms. Evidence is presented that concerns about excessive flatulence from eating beans may be exaggerated, and that there is individual variation in response to different bean types. It is recommended that nutritionists should aggressively encourage consumers to consume more legumes. They should also be advised to evaluate different legume varieties to minimise undesirable symptoms. More research is needed to assess gastrointestinal responses between types of available and consumed legumes in South Africa. The FBDG should be tested in different population groups to determine how to maintain legumes as a traditional food. Increasing familiarity with legumes could help to increase the likelihood that they may be incorporated more regularly into the diet.