by Chris Shugart
Protein and a 1000-Calorie Surplus
What happens if you eat 1000 more calories than you need? It depends on your macros. Check this out.
You'll definitely gain weight if you eat 1000 extra calories every day for weeks. But does the macronutrient composition of those calories matter? Is a "calorie a calorie" or does the source matter? What if most of those surplus calories came from protein (Buy at Amazon)? How does that affect body composition?
Wow, that's a lot of questions. Luckily, some scientists answered them all. This study was insane. Every subject lived in the metabolic research facility for three months. Every meal eaten was precisely prepared and every bite was accounted for.
Here's the spoiler: If you're going to overeat, overeat protein!
The Overfeeding Study
Researchers recruited 16 men and 9 women, all healthy but sedentary. First, they put the subjects into a metabolic chamber to determine their maintenance calorie intake. Then they all lived in the lab for a few weeks eating a weight-stabilizing diet.
Now the fun begins. Subjects were divided into three groups. All three groups were overfed by 1000 calories a day, about a 40% surplus:
- Low Protein Group
- Protein: 5%
- Carbs: 40%
- Fat: 55%
- Normal Protein Group
- Protein: 15%
- Carbs: 40%
- Fat: 45%
- High Protein Group
- Protein: 25%
- Carbs: 40%
- Fat: 35%
They all consumed the same high number of calories, but some ate more fat and less protein. Others ate more protein and less fat. Carbs were the same in all groups. Here's how the protein looked:
- Low Protein Group: 45 grams
- Normal Protein Group: 140 grams
- High Protein Group: 230 grams
All 25 subjects remained sedentary and didn't train. The researchers used every advanced method imaginable to measure their body composition and metabolic rate.
What Happened After 56 Days of Overfeeding?
This gets a little tricky, so pay attention. Yes, every group gained weight, but what happened to their body compositions and metabolic rates? Let's dig in:
- Everyone gained about 7 pounds of fat.
- The normal and high-protein group gained about 6.5 pounds of lean body mass, but the low-protein group lost 1 pound of lean body mass.
- So, the low-protein group gained less overall weight (7 pounds), but it was all fat! The normal protein group gained more total body weight, as did the high-protein group (13-14 pounds), but the extra weight they gained on top of their fat gain was all lean body mass (6.5 pounds).
- The normal and high protein groups increased their metabolisms by over 20%. The low-protein group boosted their metabolism by only 2% which the researchers called "statistically insignificant."
Quick Note: Yes, lean body mass isn't just muscle. It also accounts for organs, skin, bones, and body water. However, none of the subjects built denser bones in eight weeks without lifting. They gained mostly muscle and a little water weight. As Dr. Bill Campbell notes in his research review: "Water is the main component of muscle tissue. If you gain more muscle, by default you'll have more body water."
Wait! They Gained Muscle Without Lifting?
Yep, that's what happened with the high-protein eaters. Other studies showed this too. When even a sedentary person increases their protein intake, they gain some muscle. Dr. Campbell adds, "For many years I believed you couldn't gain lean body mass without lifting weights. I believed that you couldn't gain muscle by just eating more protein. I was wrong."
How to Use This Info
This was an overfeeding study, and everyone gained fat. But, overfeeding with lots of protein also led to gains in muscle mass and a boosted metabolism.
The subjects who ate higher-protein diets will have a much easier time losing the 7 pounds of fat they gained. The addition of resistance training would've made this study more interesting, but we could guess that lifters would've gained more muscle and maybe less fat.
For us, this study is a reminder to eat plenty of protein. The subjects were sedentary with an average body weight of 165 pounds, yet some consumed up to 230 grams daily. You may not need that much, but at least follow the Golden Rule for lifters: eat roughly 1 gram of protein per pound of body weight (assuming you're not a fat lifter).
If you're in a mass phase, shift those surplus calories to mostly protein instead of carbs and fats. You'll build more muscle and keep your metabolic rate (total daily energy expenditure) fired up.
Make it easy to hit your protein goals by adding a protein shake or two every day. Choose one containing micellar casein for best results. It's the only anti-catabolic protein, meaning not only does it increase protein synthesis, but it helps prevent muscle breakdown during and after intense training. Obviously, I'm going to suggest the one we make: MD Protein (Buy at Amazon).
One Last Thing
The men and women in the "normal protein" group consumed 140 grams daily. That's more than double the protein suggested by most dieticians, government health agencies, and WebMD. Maybe the "experts" will catch up someday.
Reference
- Bray et al. "Effect of Dietary Protein Content on Weight Gain, Energy Expenditure, and Body Composition During Overeating." JAMA. 2012 January 4; 307(1): 47-55.
Note: Special thanks to Dr. Bill Campbell for breaking down this study in his excellent Body by Science newsletter.
