I was reading something today about a small study on protein . . . . sponsored by a company that sells protein shakes, so be very sceptical . . . . but interesting anyway.
Three groups: (a) control, eating standard American diet, no exercise. (b) Standard diet, plus weight training and cardio. (c) Standard diet, plus weight training and cardio, plus protein shakes, thus increasing protein intake by about 60%.
Group (b), the exercisers, lost fat, gained muscle, and gained cardio fitness. Group (c), with the protein drinks, did the same, only more so. They gained more muscle (no surprise), lost more fat (why?) and gained more cardio fitness (why??).
I constantly read comments on Runners world to the effect that protein drinks are only for muscleheads, they don't make you fitter, etc etc, that weight loss is just a matter of calories consumed and burned; that excess protein consumed will just be stored as fat; and that all you need is to eat a decent balanced diet of "real food" and avoid the "processed crap" (to quote a recent thread). I disagree. Or at least, I disagree unless and until they provide a good definition of the words "balanced" and "processed".
Note that the people in this study improved their VO2max more with protein shakes (a measure of oxygen throughput -- sort of your "top speed"). How can this be? The people doing it hypothesised that it might be because the higher protein diet helped with recovery, and thus allowed people to train harder.
The fact that they lost fat, rather than gaining it from the extra calories consumed, is probably because drinking the shakes caused them automatically to eat less of other foods to compensate (without knowing they were doing so) and thereby reduced their intake of carbs and/or fats.
I do think that the official "recommended" amount of protein is enough to keep you alive, but way too little for optimal recovery from strenuous exercise.
Now the sceptical bit: what (I hear you cry) about that other study you blogged about a couple of years ago, which had very similar results, except with carb supplements? Where the cyclists increased their performance a lot?
Two things: the people in the carb bar study were highly trained cyclists, and highly trained athletes are much more carb tolerant than normal sedentary (or almost sedentary) people like in the protein shake study. Secondly, one reason that was hypothesised for the good results in the carb bar study was simply making them consume more of their carbs earlier in the day. There are good reasons to think that's the best time to eat carbs. And the effect of the protein shake study may be partly caused by making the (c) group eat more of their daily food earlier, as well as making more of it protein. If they drank three shakes a day, they may have snacked less in the evening. And it also may have been at least partly an effect of non-blinding. If they didn't use dummy shakes, then both the scientists and the subjects will have known who was on the protein shakes, and those subjects may just have tried harder because they knew. That happens.
My general conclusion from these studies: eat more protein than the government recommends. (Say 1.6 grams per kilo of body weight). Eat earlier. And don't eat much carbs unless you do a lot of exercise and are at your desired weight already. Eat plenty of carbs after strenuous exercise, and not much at any other time.
