Ask the Guru

QUESTION: I’ve heard that I need to cut dairy out of my diet to lose fat. Is that true?

ANSWER: A long-held idea in the bodybuilding world is that dairy makes you smooth, and the belief that it needs to be removed from a fat-loss diet (especially a contest diet) is equally strongly held. Frankly, I’m not entirely sure where the idea comes from. I suspect that some of it has to do with the fact that old-school bodybuilders often bulked up on full-fat milk. When it came time to diet, they’d stop drinking the milk, dropping their fat and calorie intake considerably, and lose fat. So milk became known as a food that kept you smooth—that is, fat. Another possibility is that the high sodium content of many dairy foods causes water retention, especially for competitors who are restricting their salt intake. Now, reducing sodium drastically while dieting creates a variety of problems, but competitors who maintain normal sodium intakes don’t seem to report bloating after eating dairy foods. Food allergies or intolerance may also cause problems. As they don’t occur that frequently, though, I doubt that every contest bodybuilder has one or the other. My money’s on the sodium. Meanwhile, emerging research suggests that eating dairy foods improves fat loss when you’re on a diet. Initially, calcium was thought to be the key nutrient, but early studies found that dairy calcium worked better than calcium supplements. While that might have been due to better absorption of dairy calcium, there is also some indication that the calcium in dairy interacts with other nutrients, such as the branched-chain amino acids. Additionally, studies have found that diets high in leucine—whey and casein contain the highest leucine content of all the proteins, and milk protein is roughly 80 percent casein and 20 percent whey—spare muscle loss. So all in all, aside from the last few days of the diet, when you need to control sodium intake, you should not take dairy foods out of a fat-loss diet. In fact, I think they can help tremendously.