Now that I’ve set the stage with the last couple posts, I want to focus in on this new study :
Effect of the protein:carbohydrate ratio in hypoenergetic diets on metabolic syndrome risk factors in exercising overweight and obese women.
As the title suggests, it looks at whether higher protein during dieting improves outcomes. It is important to note that the subjects in this study were also doing . So this is really a true test of how protein impacts the combination of calorie restriction and resistance training.
What did the authors find? From the abstract:
“Subjects reported that the NP (normal-protein) diet was easier to comply with and achieved better improvements in body fat, waist circumference and waist:hip ratio, and preservation of lean mass compared with the other two diets.”
“A diet with a 1:2 protein:carbohydrate ratio promoted better improvements than either the LP or HP diets.”
So it appears that a normal protein intake during dieting and resistance training is not just necessary, but perhaps .
I got a hold of the full-text of the paper to find out how much protein was being consumed. Here are the numbers:
Low-protein: 55.5 grams of protein per day
Normal-protein: 74.8 grams
High-protein: 100.2 grams
In Part II of this series, I showed that 80 grams of protein during dieting and resistance training was enough maintain lean mass and RMR. Now with this study, it shows that higher and lower intakes of protein actually lead to worse outcomes.
These two data points suggest that a protein intake of 75-80 grams during dieting and resistance training is certainly enough, and may even be the preferred amount.
One caveat is that this second study was done with women only, and therefore the results could be different in men. The first study (the 800 calorie study) had both men and women as subjects.