On balance, a balanced macro diet is best

I entered the carb wars with my first book, The Testosterone Advantage Plan, published in 2002. The diet my coauthors and I recommended emphasized protein and healthy fats and said some discouraging words about carbohydrates. Still, between one-third and two-fifths of the calories in the diet came from carbsprimarily fruits, vegetables, beans, and whole grains, along with the carbs in nuts and dairy products. The book wasn't controversial at all in the outside world, six years after The Zone had immortalized "40/30/30," its recommended combination of 40 percent carbohydrate, 30 percent fat, and 30 percent protein. That was more or less what we recommended, although we couldn't think of any reason why anyone had to hit this ratio with every single meal, as The Zone required. But inside the company I worked for at the time, you'd have thought we were telling readers to eat sticks of butter dipped in Crisco. Colleagues of mine were lobbying our bosses to kill the book. They lost that battle, but won in the end. Our own company published the low-carb South Beach Diet in the spring of 2003, and everyone forgot Testosterone Advantage Plan even existed. SBD, which came out the same week that Dr. Robert Atkins slipped on a patch of ice and suffered a fatal brain injury, put a friendlier face on the advice to avoid carbs-call it "compassionate carbophobia. " Its flexibility also helped dietconscious readers back away from their Zone-inspired obsession with macro nutrient ratios. Ironically, this change came just as nutritional science was inching toward an unspoken consensus on the ideal combination of carbs, fat, and protein. Most intriguing to me was a study from Tufts-New England Medical Center published in 2005. It compared four popular diet plans-Atkins, Zone, Weight Watchers, Omish-by placing actual people on them for a year. But the study wasn't just about weight loss; if it had been, the super-low-fat Omish diet would've been judged the best. (There was little difference in weight loss across the board; the "best" and "worst" of the four were separated by less than 3 pounds of weight lost in twelve months.) It also looked at adherence-who stuck with each diet. The adherence winners were Zone and Weight Watchers; 65 percent of the participants in each group followed the diet for a year. Omish came in last, with just 50 percent adherence versus 53 percent for Atkins. I came away with the idea that none of the diets worked particularly well. But that's not really fair to any of them. There 's a huge difference between Omish and Atkins, and a lesser but still important distinction between Weight Watchers and the Zone. Weight Watchers is agnostic on the subject of macronutrients-all foods are assigned points based on a variety of factors, and you can eat them in whatever combination you choose, as long as you stick to a set point total per day. The Zone, meanwhile, fetishizes the importance of hitting the right combination every time you eat. So why didn't those differences matter, in terms of weight loss? My guess: because people are as different as the four diets. In the real world, nobody is randomly assigned to a diet as extreme as Atkins or Omish. That only happens in scientific research. If you choose to go to those lengths to lose weight or improve your health, it's something you inflict upon yourself. Had someone randomly assigned me to the Omish plan, I'd have dropped out the first week. And if someone who wanted to try a low-fat diet got stuck in the Atkins group, I'd expect a similar reaction. No study is perfect, though, and most of the ones I 've seen show at least a bit of bias in their design. A study that plays it straight with four very different and potentially controversial diets is to be admired, and to be taken seriously. And if we take this study seriously, we see that the Zone diet comes out best, by a nose. It was tied for the best adherence, and offered the secondbest weight loss. You can find support for the idea of balancing macro nutrients just about anywhere you look. Studies that compare higherprotein plans with lower-protein plans almost always show that the protein makes a difference. (I say "almost always " because no conclusion holds in every single published study.) That is, the diet plan with more protein usually comes out ahead. The magic number seems to be about 30 percent of total calories. That's twice the amount of protein you'll find in a typical American diet, but it's a feature in the Zone, Atkins, and South Beach diets. A variety of studies and reviews suggest that if 30 percent of your daily calories come from protein, you'll end up eating fewer total calories, since protein is more satiating, leaving you feeling fuller longer between meals. You'll also probably weigh less, since protein requires a lot more energy to digest than any other macronutrient.