Burn More Fat Without Losing Muscle
Cutting calories often leads to muscle loss, but a new review suggests increasing protein intake can help you lose more fat while maintaining—or even gaining—muscle.
The Science of High-Protein Fat Loss
Researchers analyzed 29 randomized controlled trials on non-obese individuals aiming to lose fat while lifting weights. They found that protein intake plays a crucial role in preserving muscle during a calorie deficit.
Standard protein recommendations fall between 1.6 to 2.2 grams per kilogram of body weight (or 0.6 to 1 gram per pound). However, the study found that leaner individuals can benefit from eating even more—up to 4.2 grams per kilogram of fat-free mass.
How Much Protein Do You Need?
For every additional gram of protein per kilogram of fat-free mass (up to 4.2 g/kg), the probability of retaining muscle increased significantly. But there’s a key point: this only works if you’re in a calorie deficit and lifting weights consistently.
If you’re not extremely lean, sticking to general protein guidelines is enough. However, if you’re looking to get shredded, here’s how to estimate your fat-free mass and optimize protein intake:
Weigh yourself.
Estimate your body fat percentage (using calipers, a scale, or this tool).
Calculate fat mass: Multiply your weight by your body fat percentage.
Example: If you weigh 200 lbs at 20% body fat, your fat mass is 40 lbs (200 x 0.2).
Find your fat-free mass: Subtract fat mass from body weight.
Example: 200 lbs - 40 lbs = 160 lbs of fat-free mass.
Determine protein intake: Convert fat-free mass to kilograms (160 lbs ÷ 2.2 = 72.7 kg), then multiply by 2.5 to 4.2 g/kg to find your protein range.
Should You Max Out Your Protein?
There’s no need to immediately jump to 4.2 g/kg—gradually increasing your intake is more sustainable. Plus, if you’re above 15-20% body fat, you don’t need to push protein to the upper limits yet. Stick with 1.6-2.2 g/kg and focus on fat loss first.
Bottom line? Protein matters, but so does a calorie deficit and proper training. Get lean first, then fine-tune your protein intake to preserve as much muscle as possible.
