Most people who work out, especially if that workout is lifting weights, do so for the effects on body composition. They either want to lose fat, or gain muscle, but the question always comes up: how to lose fat and gain muscle at the same time.
Many fitness experts even deny that it can be done, and given how difficult it is to change body composition, that is, after the newbie stage, I’ve wondered myself. However, there’s actually some proof that it can be done in a published paper: Effect of a Hypocaloric Diet, Increased Protein Intake and Resistance Training on Lean Mass Gains and Fat Mass Loss in Overweight Police Officers (ref, full paper).
The policemen – they were all men – in this study were out of shape, overweight, and between the ages of 28 and 40. They complained generally that they had been gaining weight and losing strength when compared to the years of their prime. Their average age was 34, and their average weight was 99 kg (218 pounds).
Importantly, their lifestyle was just crappy and conducive to ill health. Carbohydrates made up 60% of their calories, with nearly half of that being sugar, and 75% of them did not even meet the 0.8 g/kg RDA for protein; 70% of them ate 50% of their calories right before sleep, and they worked day, swing, and night shifts.
So, they had poor sleep habits, and it appears that their diets were largely filled with sugar- and carb-laden junk, with not even close to enough protein. No wonder they became overweight and were losing strength.
The researchers divided the men into three groups; all of them went on a low-calorie diet, nothing too drastic at 80% of projected calorie expenditure, about 2200 calories a day.
The two extra-protein groups got their total protein intake up to 1.5 g/kg body weight daily, about double what they were used to consuming.
After 12 weeks, the diet-only group lost 2.5 kgs (5.5 pounds); all of this was fat, with no significant change in lean mass. Not really a very exciting result for 12 weeks of dieting.
The second group – diet + resistance training + whey protein, lost 4.2 kg fat and gained 2.0 kg of lean mass. Much better.
The third group – diet + resistance training + casein protein, lost 7 kg of fat, and gained 4 kg of lean mass. A great result.
So we see that it is possible to lose fat and gain muscle at the same time. A high protein diet, including protein supplementation, and weight training, can do this.
You knew there was going to be a “however”. The subjects were really fat and out of shape to begin with, averaging 27% body fat and 218 pounds. Obviously it’s a lot easier to get someone into decent shape when they start from a low base than it is to improve someone who already eats right and works out. If you lift weights regularly, eat a decent diet with enough protein and little in the way of refined carbohydrates, then it will be difficult to add 4 kgs (9 pounds) of muscle and lose a lot of fat in 12 weeks just by making a few changes, such as adding more protein and eating a hypocaloric diet.
Of interest here is that the group that took casein lost more fat and gained more muscle than the group that took whey. Researchers have studied whey far more than casein, and generally whey seems to have the better results, but that was not the case here.
The same authors had done a study on burn patients. Severe burns result in a highly catabolic state and these patients typically lose a lot of weight and a lot of muscle. Of two groups, one on a high calorie diet, and the other on the same diet but with 70 g/d of casein protein added, the casein group gained weight twice as fast and had better gains in muscle strength (ref).
Whey protein is high in BCAAs and leucine and causes a spike in these amino acids in the bloodstream shortly after taking it, and then a decline not long thereafter. (See graph at the top of this post.) Whey also has high levels of cysteine, the rate-limiting amino acid in glutathione production, so whey helps relieve low glutathione and oxidative stress. With casein there’s no spike, since it is a slow-digesting protein, but it stays in the system much longer. Neither is casein a rich source of cysteine.
For those of you who wish to try casein, a couple of caveats. Casein is probably somewhat pro-aging, since it increases IGF-1 levels – meat and whey do not, or at least not as much. Another caveat is that I’ve seen studies in which it’s recommended to take casein before bedtime, and lifters who do this do gain more muscle. But, it will also completely abolish normal overnight autophagy, so this is another way that casein could be pro-aging. I’m still very interested in gaining muscle, and I do take casein on occasion, but I want my autophagy to proceed normally and daily, so I won’t be taking it before sleep.
Casein could be a very effective way to gain muscle and lose fat when combined with a low-calorie diet and resistance training. But if you’re anything but an out-of-shape newbie, don’t expect the kind of gains you see in this study. The study does show how it can be done however, and whether you’re really out of shape to begin with, or a seasoned fitness veteran, the principles remain the same.