Avoid black beans on the keto diet if you can’t add them to a recipe with at least six servings (1). Also, a cup of lima beans has 26.1 g of net carbs, and a cup of pinto beans has 29.45 g of net carbs (18, 5). Splitting the macros into recipes with six or more servings will mean you eat 4.35 g of net carbs per serving with lima beans and 4.9 g with pinto beans.