Whenever I give a sports-nutrition seminar, I give the audience a pop quiz. I ask how many believe that breakfast is the most important meal of the day. Typically, the vast majority of the audience members put up their hands. I remind them that research proves that skipping breakfast impairs fasting lipids and postprandial insulin sensitivity—and that could lead to weight gain.1
There’s clear evidence that eating breakfast is associated with a healthier bodyweight.2 Even so, the audience is dead wrong. The most important meal of the day isn’t breakfast. It’s what you take in during the nutrient timing window: the preworkout, workout and/or postworkout period. Although we know breakfast is important for regulating bodyweight and contributing to overall health, there’s no evidence that it has any impact on the adaptive response to exercise.
On the other hand, robust evidence shows that eating the proper nutrients—i.e., combinations of amino acids from protein and carbs—may indeed lead to larger muscle fibers, less bodyfat, better recovery and better performance. Eating corn flakes in the morning ain’t gonna do that! The caveat: This discussion applies only to those who exercise. If you’re a sedentary slob, it doesn’t matter because you don’t have a nutrient-timing window. If you’re reading this, however, there’s a pretty good chance you’re a serious bodybuilder or fitness maniac.
In one study, young men were randomly assigned to protein, placebo or control groups. Muscle cross sections and muscle forces were analyzed before and after 21 weeks, with one group doing heavy resistance training. The subjects got protein—15 grams of whey both before and after exercise—or a placebo. The protein group increased muscle size more than the other groups.3 The study confirms earlier work that compared the effect of resistance training combined with timed intake of the same number of calories of protein and carbohydrate supplementation on muscle fiber hypertrophy and mechanical muscle performance.
Supplementation was administered before and immediately after each training bout and in the morning on nontraining days. After 14 weeks of resistance training, the protein group showed 18 percent and 26 percent increases in the size of their slow- and fast-twitch muscle fibers, respectively. They also improved their performance, while the carb group did not.4
Does that mean you don’t need carbohydrate to get muscle hypertrophy? Yes, it does, but think of it this way: If your goal is to gain the most bodyweight possible—both lean body mass and fat mass—a combination of carbs and amino acids, meaning protein, is perfect. If you’re willing to sacrifice some gains in lean mass so that you don’t gain any fat, however, go for the protein and/or aminos by themselves. Either way you have to time the nutrients for maximal growth. And don’t skip breakfast.
—Jose Antonio, Ph.D.
Editor’s note: Jose Antonio, Ph.D., is the CEO of the International Society of Sports Nutrition (www.theissn.org) and is a sports science consultant to VPX/Redline.
1 Farshchi, H.R., et al. (2005). Deleterious effects of omitting breakfast on insulin sensitivity and fasting lipid profiles in healthy lean women. Am J Clin Nutr. 81:388-96.
2 Song, W.O., et al. (2005). Is consumption of breakfast associated with body mass index in U.S. adults? J Am Diet Assoc. 105:1373-82.
3 Hulmi, J.J., et al. (2008). Acute and long-term effects of resistance exercise with or without protein ingestion on muscle hypertrophy and gene expression. Amino Acids. In press.
4 Andersen, L.L., et al. (2005). The effect of resistance training combined with timed ingestion of protein on muscle fiber size and muscle strength. Metabolism. 54:151-6.