Eating tons of protein won’t do a thing to negatively affect your body fat levels. Here’s why.
Nearly every dietitian will tell you that eating extra protein leads to extra body fat storage, just like it can with excess carbs and fats. After all, a calorie is a calorie.
But it’s hogwash. And it’s probably that belief that’s to blame for so many people failing to make progress. When most people lower calories to lose weight, they also lower their protein intake. They treat protein like just another macronutrient: one that must be reined in to lose fat.
But the truth is, eating a lot of protein, even up to 5.5 times the recommended daily allowance, won’t make you gain any additional fat, even if all that protein adds a ton of calories to your diet. Instead, it seems to have a protective effect against fat during periods of increased calorie intake while also leading to additional muscle mass, provided the circumstances are right.
Overfeeding carbs and/or fat results in body comp changes that are different from overfeeding on protein. Dietary protein has a protective effect against fat gain during periods of overeating. How protective?
In one study, researchers randomized subjects to partake in one of three diets:
- Low protein (5%) – Around 47 grams daily
- Normal protein (15%) – About 140 grams
- High protein (25%) – Around 230 grams
Randomized subjects were then “force-fed” 140% of their maintenance calories – about an extra 1,000 calories for 8 weeks straight.
Carb intake was kept at about 41-42% between the groups, while dietary fat ranged from 33% in the high protein group to 44% and 52% in the normal and low protein groups, respectively.
After doing their dual X-ray absorptiometry (DXA) magic, the scientists found that while all subjects gained approximately the same amount of fat (the high protein group gained a little less than the other two groups), the high protein group gained about 6.6 pounds of lean mass.
I know what you’re thinking: “Hey, all three groups gained the same amount of fat. Where’s this alleged protective effect of protein?”
Slow down. The participants were not resistance-trained. Neither did they perform any exercise during the study. That extra 6.6 pounds of lean mass fell on them like manna from heaven. Clearly, their results showed that excess protein during an overeating phase contributed to lean body mass gains. That throws a high-protein pie in the face of all those dietitians who still insist that a calorie is a calorie.
But what would happen if someone took it one step further and conducted a similar study, but this time with resistance-trained athletes and an even higher protein intake?
Dr. Joey Antonio set about to “determine the effects of a very high protein diet (4.4 g/kg/d) on body composition in resistance-trained men and women.”
The study design was simple: Thirty healthy weight-lifting men and women were randomly assigned to a control (CON) group or a high protein (HP) group. The CON group was instructed to maintain their same training and dietary habits over an 8-week period. The HP group was also instructed to maintain their same training and dietary habits (same carb and fat intake), albeit with the added instruction to take in 4.4 grams of protein per kilogram of body weight (about 5.5 times the RDA).
The math shows that the high-protein group would be ingesting around 800 calories per day more than the control group. These additional calories were all from protein.
Here’s the clincher: After 8 weeks, despite eating about 800 extra calories per day – all of it from protein – the high protein group experienced no changes in body weight, fat mass, or fat-free mass.
You probably have mixed feelings about those results. On one hand, you’re probably elated that all those extra calories from protein didn’t result in any additional tubbiness. However, you’re probably disappointed that it didn’t lead to any additional muscle mass. Read on for a clearer picture.
In the first study (Bray, et al.), the untrained subjects gained 6.6 pounds of lean mass just by increasing protein intake to about 230 grams per day. No exercise was involved, so this suggests that they weren’t getting enough protein to begin with, which casts dark aspersions on the U.S. recommended daily amount of protein (about 63 grams for a 175-pound person).
That brings us to Antonio’s study: Why did the high protein group, despite ingesting about 5.5 times the RDA for protein, fail to gain any lean mass, let alone fat mass? In a nutshell, because they were already working out, and it’s very difficult for trained subjects to gain lean body mass without significant changes in their training program, especially in just 8 weeks. Add a few more months and a bodybuilding-focused training plan, and we’d have seen gains in lean body mass.
Well, protein can turn into body fat, but it’s unlikely. Biochemically, turning dietary fat into body fat is easy-peasy, and turning carbs into body fat isn’t that much more difficult.
Turning protein into body fat, however, is an entirely different type of challenge. It takes several biochemical and hormonal steps, and it’s monitored closely by the liver, which metes out amino acids according to the body’s metabolic needs (tissue breakdown, tissue synthesis, catabolism, anabolism, etc.)
As such, you can believe, with a high degree of certainty, that protein has a protective effect against fat gain in times of caloric surplus, particularly when combined with lifting.
All this might not be news to you, but it’s something that we need to be reminded of because it’s so contrary to what we used to believe or what many dietitians currently believe.
Here’s what I think you should take with you from this article:
Regular, non-training people should probably throw the 0.8 grams of protein 15 per kilogram RDA out the window and strive for at least 50% more.
For most lifters who want to add muscle (but repeatedly fail), you likely need to eat more protein; maybe not 5.5 times the RDA, but maybe more than what you’ve previously believed to be adequate. The added calories will not turn to fat.
Lastly, it’s probably impossible to eat that much extra protein from whole food sources. You must, as the subjects in Antonio’s study did, augment whole-food protein choices with a quality protein powder, like MD (on Amazon).
A simple fix? Adopt a protein-first eating strategy: just add two 2-scoop protein shakes to your daily diet and well, the rest pretty much takes care of itself. More info here: The Protein-First Diet Strategy.
- Antonio J et al. The effects of consuming a high protein diet (4.4 g/kg/d) on body composition in resistance-trained individuals. J Int Soc Sports Nutr. 2014 May 12;11:19. PubMed.
- Leaf A et al. The Effects of Overfeeding on Body Composition: The Role of Macronutrient Composition – A Narrative Review. Int J Exerc Sci. 2017;10(8):1275-1296. PMC.
- Bray GA et al. Effect of protein overfeeding on energy expenditure measured in a metabolic chamber. Am J Clin Nutr. 2015;101(3):496-505. PubMed.