Question:

I have done body building in the past and know that the perfect combination of protein/carbs/fats produce results with respect to giving the body what it needs to develop lean muscle and lose fat. This is done in part by measuring body fat and weight. How would you calculate this because I had someone do it for me in the past and don’t know how to do it myself. It was broken down into total protein, carbs and fats for the  whole day and further broken down per meal. Can you duplicate this process?

– Alisa O.

Answer:

I will admit that I am not sure what “perfect combination” of macro-nutrients you are referring to. One’s individual body composition can be used to help create personal nutritional goals. Actual nutrient needs are much more complex and depend on protein turnover, nitrogen loss and metabolism. Also, nutrient quality, timing and frequency have an impact on developing lean muscle and losing fat.

That said, I like the summary bodybuilding recommendations from an article in the Journal of the International Society of Sports Nutrition*:

Diet component                                     Recommendation

Protein (g/kg of lean body mass)           2.3-3.1

Fat (% of total calories)                          15-30%

Carbohydrate (% of total calories)          remaining

Let’s work through these with a sample 2,000 calorie diet for a 160-pound person with 15% body fat.

• His or her lean body mass is 62 kg (from 72.73 kg x 0.85).
• Protein: Recommended range is 142-192 grams (from 62 kg x 2.3-3.1 g/kg). Energy-wise, this amount of protein provides 568-768 calories.
• Fat: Recommended range is 300-600 calories (from 2,000 x .15-0.3). This equates to 33-67 grams of fat.
• Carbohydrate energy would be the remainder; we’ll use the range midpoints to get 882 calories (from 2,000 – 668 protein – 450 fat). By grams, this would be 220 grams of carbohydrate.

Apply the recommendations to your own anthropometrics and total energy need to get a possible ideal combination of macro-nutrients for your goals.

*Evidence-based recommendations for natural bodybuilding contest preparation: nutrition and supplementation.  Helms, ER, Aragon AA, Fitschen PJ. Journal of the International Society of Sports Nutrition 201411:20

– Debbie J., MS, RD