Gaining muscle. Most mature adults can gain a maximum of 15 pounds of muscle in a year but many can only gain 5lbs of muscle a year. That’s only 1.25 pounds of muscle gain per month maximum – pretty slow whether you are losing fat at the same time or not. In rough numbers, to gain that 1.25 pounds of muscle each month while maintaining your current bodyfat you should eat an additional 3125 calories more a month, that’s about 100 more calories a day – not much of a calorie surplus.
Losing fat. Now lets look at losing fat, its much faster than gaining muscle. You lose fat when you consume fewer calories than you burn off in a day (the TDEE). For an average person losing weight, they will eat about 400 calories a day less (12, 000 calories a month) than their TDEE to lose a pound of fat a week, or 52 pounds of fat in a year.
Now lets talk about the exceptions to this, those who can’t gain muscle and lose fat:
- Losing fat and gaining muscle at the same time is very difficult for advanced bodybuilders. Many of them are close to their genetic limits so adding muscle is very difficult and slow for them even under the best of circumstances. Losing fat and gaining muscle at the same time is something that only beginning and intermediate bodybuilders can do. (By my somewhat arbitrary definition, an advanced bodybuilder is someone who can do 8 flawless, ultra slow-motion pullups and 20 flawless, ultra slow-motion pushups.)
- Skinny teens who can’t gain either fat or muscle even when they eat as much as they can.
- Advanced bodybuilders with low bodyfat (under 8%).Your body needs some fat so when you get to a certain point, your body will start choosing to burn muscle instead of fat if you have a caloric deficit. If you are 8% bodyfat and want to get down to 4-6% bodyfat you wont be able to add muscle while you do this, at best you can do is to maintain your muscle mass. With regular dieting, its tough to drop down to 4-6% without losing muscle mass but carb cycling seems to really help for this specific purpose.