What We Know About Higher-Protein Diets
Based on a bevy of studies we've covered previously on T Nation, here's what we know:
- A fat-loss diet that's higher in protein leads to more fat loss and more muscle preservation than a diet lower in protein... even if overall calories are the same in both diet plans.
- A diet higher in protein leads to more muscle gain than a diet lower in protein... again, even if calories are kept the same.
- A diet higher in protein leads to less belly fat than a lower-protein plan. You guessed it... even if calories are the same in both diets.
- Protein is the most satiating (filling) of the three macronutrients. So a high protein fat-loss plan will make you less crazy than a low-protein diet plan.
- It's very difficult for your body to convert protein into body fat, even at very high amounts. If a larger chunk of your diet is made up of protein, you'll be able to eat more and still lose fat.
- Increasing protein intake above the usual recommended levels enhances protein synthesis, lean body mass, postprandial thermogenesis, and cardiometabolic health.
All very cool. But is there a difference between whole-food protein sources and protein powders? Science has taken a look.
Researcher Paul Arciero and his team did a previous study where they put two groups of people on a diet plan. Both groups consumed the same number of calories and did the same workouts, but one group ate 3 larger meals per day and one group had 6 smaller meals per day (half of those meals consisting of protein powder). In short, the frequent eaters had better improvements in body composition – more muscle and less fat – than the "three square meals a day" group.
But the researchers wanted to take this a step further. How would 6 solid meals per day compare to 3 solid meals and 3 protein shakes?
They put two groups of chubby but otherwise healthy people on a relatively high protein diet, at least "high" for regular folks: 1.4 g/kg body weight. Both groups practiced "protein pacing" for 16 weeks, meaning they both had 5-6 feedings per day. One group consumed half their meals in the form of whey protein. Both groups did the same workouts (weights and cardio mostly).
Both groups improved their body compositions and their physical performance. The group that had 3 meals from protein powder improved just as much as the whole-food eaters. In short, a whey protein supplement works just as well as solid food protein sources.
So that answers the question: "Is protein powder as good as whole food when it comes to improving body composition and performance?" Yes.
Since most bodybuilders and lifters eat multiple meals per day, it's fast and convenient to supplement some of those feedings with protein shakes. And now we know it's at least as good as whole foods for fat loss or muscle gain. So tell those pudgy dieticians to get off your back.
Now, the researchers chose whey protein because whey has been shown to be superior than soy protein, pea protein and other types. But what about a high quality micellar casein or a blend of whey and casein?
Micellar casein is more slowly digested than whey and has a distinct advantage due to its ability to amplify nitrogen retention. (Increased nitrogen retention is essential for muscle performance.) In other words, casein is generally a better muscle builder and a better fat burner than plain ol' whey. Intact micelles equate to a gradual release of amino acids and higher concentrations of leucine in the bloodstream. Plus, micellar casein is anticatabolic.
The scientists here didn't study the effects of micellar casein or a casein/whey blend, but we can guess that if it had been used, the protein supplementing group may have pulled ahead of the whole-food only group.
- Arciero PJ et al. Protein-Pacing from Food or Supplementation Improves Physical Performance in Overweight Men and Women: The PRISE 2 Study. Nutrients. 2016 May 11;8(5):288. PubMed.