This is best achieved by eating generous amounts of protein and moderate amounts of carbohydrates, since carbohydrates cause little glucagon release. When we eat large amounts of carbohydrate-dense foods and little protein, we cause insulin levels to be more elevated, with resultant storage of fat. This is another reason why foods such as pasta, rice, and potatoes are to be avoided. Of course, there is protein in plant foods, especially legumes. The problem with using these as a primary protein source is that in most cases there is a good deal more carbohydrate than there is protein.
Many beans are quite starchy, in fact.
The best source of protein is therefore meat and eggs. Ancient humans would have eaten meats that were relatively low in saturated fats, compared to modern feedlot corn-fattened cattle. Recent research suggests that it is not the amount of fat in the diet that matters, but the kind of fat. The n3 fats are found in oily fish, such as tuna, sardines, salmon, and mackerel. They are also found in the fats of wild animals.