If calories are low during a diet, does the macro ratio really matter? We have the nuanced answer.
In the last decade, we've seen two distinct diet trends:
"Prioritize protein to stay full, get lean, and retain muscle."
And...
"A calorie is a calorie. Just eat less to lose fat."
Oddly, the proponents of both often point back to the same 2012 study to defend their positions. There's a lot we can learn from that study, but many people have misinterpreted it.
The study
Researchers put overweight men on one of two calorie-restricted diets for a full year:
- High-protein diet (more protein, fewer carbs)
- High-carb diet (more carbs, less protein)
Both diets had the same total calories, about 1670 daily. The participants were told to keep their activity levels the same. Most weren't training so they kept, um, not training.
Who lost the most weight? Well, here's where the study gets misinterpreted. Officially, both groups lost a similar amount of weight over the year. The difference in total weight loss between groups was small and considered "not statistically significant." But let's look at the actual numbers:
- The high-protein group lost 27.1 pounds.
- The high-carb group lost 24 pounds.
So, the group eating more protein actually lost 3 extra pounds.
Let's dig deeper. The high-protein group lost about 22 pounds of body fat (fat mass, not just scale weight). The high-carb group lost only about 16 pounds of body fat. So, the high-protein group lost roughly 6 pounds more body fat than the high-carb group (on average).
Neither group was lifting weights while eating their low-calorie diets, so both lost some muscle. The high-carb group lost just over 8 pounds of fat-free mass. The protein group lost only about 5 pounds, meaning they preserved more metabolism-boosting muscle. They had a better body composition at the end of the study, and their blood markers improved faster.
The just-eat-less and "a calorie is a calorie" fanboys point to this study to "prove" that a person can lose weight with any type of diet if calories are controlled. That's not untrue, but the distinction lies in the details.
A higher-protein diet actually leads to more scale-weight loss, more actual body fat loss, and more muscle retention. And the more muscle you retain during a diet, the more likely you are to keep the fat off. Oh, and you'll look better naked.
How much protein should I eat when dieting?
In the study, the lower protein group consumed about 80-90 grams of protein per day. The more successful higher-protein group consumed 130-140 grams of protein per day.
While the higher-protein eaters weren't consuming a "lifter's amount" of protein – about a gram per pound of body weight – they were eating enough to meet their body's protein threshold. That's the amount of protein required daily to keep you full and satisfied. Most Americans don't meet that threshold, which partly explains their general fatness.
How to use this info
When dieting, get at least 35% of your total calories from protein. That's the bare minimum, and more is better if your goal is to favorably shift your body composition – less fat, more muscle.
If you're already in decent shape and just need to drop 10 or 20 pounds, eat about a gram of protein per pound of body weight. If you're very overweight, choose a healthy goal weight and eat that many grams daily.
To avoid muscle loss, lift weights. And to guarantee full muscle retention, get some of your protein from micellar casein, the anti-catabolic protein source that also happens to keep you full longer than any other protein.
MD Protein ➔ Buy at Biotest is made with micellar casein, and it's a low-carb flavor bomb which helps make any diet easier. Just have a shake or two per day or add Metabolic Drive to healthy recipes, like these low-carb protein pancakes.
For more info, check out: Dual-action protein: The real timeline of benefits.
Reference
- Wycherley, T. P., et al. "Comparison of the Effects of 52 Weeks Weight Loss with Either a High-Protein or High-Carbohydrate Diet on Body Composition and Cardiometabolic Risk Factors in Overweight and Obese Males." Nutrition & Diabetes, vol. 2, 2012, article e80. https://doi.org/10.1038/nutd.2012.3.