That being said though, here are a few simple guidelines from the folks at Precision Nutrition for measuring your food intake if you don’t have access or don’t prefer to use a food scale: Palm = 1 serving for protein sources (~5-6 ounces) Length of your thumb = 1 serving for fat sources Cupped hand = 1 serving for carbohydrate sources Fist = 1 serving for vegetables I should also note that most folks will have to recalculate macros routinely (every 4-6 weeks) and add calories if their weight isn’t increasing.