Muscle-Building Math

You gain muscle and lose bodyfat not by eating less, but by eating properly.

Muscle-Building Math


I’ve been trying for a year to gain muscle mass by eating more and training hard, but it’s not working. What should I do? 


Factors such as training, outside activities and rest are involved, but it sounds as though it could be primarily a matter related to bodytype. You are probably an ectomorph — an individual with a lean bodytype and a fast metabolism who finds it difficult to gain weight. That means you need more calories than either a mesomorph (someone more muscular who gains weight a bit more easily) or an endomorph (a person who gains bodyfat easily) in order to put on appreciable mass. Those with mesomorphic or endomorphic tendencies have resting metabolic rates slower than yours; they don’t burn calories as rapidly, so they don’t need as much food to build muscle as you do. 

An average male endomorph’s resting metabolic rate may be only 1,500-1,800 calories a day; an average male mesomorph’s, 1,800-2,000; an ectomorph’s might be up to 2,300 or so. That’s a bit of a difference in the amount of food you need in comparison just to maintain your weight. Also, factor in the amount of calories you burn in your workouts. Say 2,300 calories a day is your resting metabolic rate. If you burn another 1,000 calories working out, you need 3,300 calories daily just to maintain your weight. 

Your goal, however, is to gain muscle mass, so you must increase your caloric intake even more. Try adding another 700 calories, bringing your minimum daily total to 4,000. If you gain muscle from that amount without gaining bodyfat, you’re making progress. However, even those gains won’t necessarily indicate that you are at your optimum caloric intake. If, after that increase, you have yet to gain bodyfat, perhaps you can handle still more calories, for faster gains. In that case, gradually increase your consumption in 300-calorie increments, and see what happens. Unlike a lot of guys who cut down on food intake in the weeks before a contest, I went as high as 5,000 calories a day; I was training so hard that I needed every one.

Select your calories from the right sources. Obviously, they should not be “empty” calories, such as candy, soda and sugar-laden desserts. Make sure your meals are nutritious and include meat, dairy, eggs, whole grains, potatoes, vegetables and fresh fruit.

Start with a baseline ratio composition for your meals of 40-50% of total daily calories from carbohydrates, 30% from protein and 20-30% from fat. As you increase your food intake (calories) to the point where you are teetering on the margin of gaining bodyfat, do not immediately reduce your food intake; instead, change its composition. Adjust your nutrient ratio to 30-40% of calories from carbohydrates, 40% from protein and 20-30% from fat. That will provide your body with a more consistent and longer-burning source of energy from the protein. Most important, keep in mind that you gain muscle and lose bodyfat not by eating less but by eating properly.


ECTOMORPH (goal of 4,000 calories per day)

  • 30% protein = 1,200 calories or 300 grams
  • 40-50% carbohydrates = 1,600-2,000 calories or 400-500 g
  • 20-30% fat = 800-1,200 calories or 90-135 g 

MESOMORPH (goal of 3,500 calories per day) 

  • 30% protein = 1,050 calories or 263 g
  • 40-50% carbohydrates = 1,400-1,750 calories or 350-438 g
  • 20-30% fat = 700-1,050 calories or 78-117 g 


For access to exclusive fitness advice, interviews, and more, subscribe on YouTube!