Beef liver | Looking for the most nutrient-dense food available? This is it. Liver is packed to the max. It has creatine for strength, carnitine for testosterone support and fat metabolism, B vitamins for energy and metabolism, and iron to support the production of myoglobin (the energy compound in muscles that contributes to recovery and nutrient delivery). Beef liver just might be one of the best bodybuilding foods of all time. Try eating six to eight ounces (precooked weight) twice a week. These amounts of liver contain, respectively, about 230 and 308 calories, 36 and 48 g of protein, 6 and 8 g of fat and 7 and 9 g of carbs. (Equivalent amounts of precooked lean beef have approximately the same number of grams of protein, more calories and fat, but no carbs.)