Fat Go up as carbs go down
The classic way for bodybuilders to construct their diet plan is like this: Protein first, and then tinker with the balance between carbs and fats until you find the sweet spot that works for you. Often, the protein stays consistent, regardless of whether the goal is muscle gain or fat loss.
This approach works wonders because it prioritizes the nutrient most people neglect most—protein—and gives endless room for customization in the other two macronutrients. Appropriately, I advise that, as you age, your fat intake should largely be determined by your carb intake.
In other words, while someone who is younger and still sensitive to the anabolic effects of carbohydrates may be better off consuming lower fat (never lower than 0.2 grams per pound of body weight) with more carbohydrates, an older individual may want to consume fewer of their calories from carbohydrates, and more from protein and fat.
Muscle growth fat recommendations by age:
- < 20 years: 0.25-0.45 grams per pound of body weight
- 21-40 years: 0.35-0.55 grams per pound of body weight
- 41-65 years: 0.45-0.65 grams per pound of body weight
- > 65 years: 0.55-0.75 grams per pound of body weight