Legumes
Alfalfa, beans, peanuts, peas, lentils, and soybeans. These foods, often incorrectly classified by many consumers as vegetables, are heavily domesticated and were “recently” introduced into the human food supply, much the same as grains. While legumes offer a good source of protein, fiber, potassium, and antioxidants, they also provide significant levels of carbohydrate and increase the overall insulin load of your diet. Furthermore, legumes contain those pesky antinutrients lectins. As Paleo Diet author Dr. Loren Cordain explains, “Most legumes in their mature state are non-digestible and/or toxic to most mammals, when eaten in even moderate quantities.”
The fact that legumes need to be altered for human consumption through cooking, soaking, or fermenting should be our best clue to avoid or strictly minimize their consumption (all truly safe fruits and vegetables can be eaten either raw or cooked). To tiptoe into a sensitive subject, the beans that are consumed liberally by many world cultures (kidney, pinto, black beans, lentils) come with the annoying by-product of flatulence, caused by the fermentation of indigestible carbohydrates.
While soy has achieved great popularity as a “healthy” alternative to meat, unfermented soy products contain compounds that may interfere with thyroid hormone production and have demonstrated an estrogenic (feminizing) effect in certain tissue. That said, soy products do have decent nutritional value and certain fermented products may be less objectionable (tempeh, natto, etc.).
I understand that many people have a strong affinity for legumes and that legumes enjoy a reputation as a healthful food category, particularly among vegetarians, who otherwise have limited protein options. It will not be a disaster if you occasionally dip your vegetables in hummus at a dinner party, fry some tempeh with vegetables for a main course, or enjoy side dishes of peas, lentils or steamed beans. However, emphasizing legumes in your diet is an inferior strategy to having vegetables, fruits, nuts and seeds, and animal foods as your primary meal and snack choices.