But if you dig in a little deeper, that’s not the whole story. The first study shows that “The HP group lost less lean body mass than the NP group.” The second study, when you look at the full-text, shows that resting metabolic rate declined for both the normal-protein and higher-protein diets, but it declined more in the normal-protein diets.
Remember from the previous post that resistance training is the key factor for maintaining lean mass and RMR during calorie restriction. In these new studies, subjects were not performing resistance training, and this is why the lean mass and RMR dropped.
Now, from this context, you can see that high-protein diets are simply “less bad” than normal-protein diets IF a person is dieting and NOT doing resistance training.
But why prescribe a diet without resistance training, knowing what previous studies have shown? Beats me. In other words, if we know calorie restriction plus resistance training generally maintains lean mass and RMR (and hence reduces the odds of weight regain), why are we quibbling over protein intake in dieting subjects NOT performing resistance training?