"But you're so thin." I got some version of that every time I told someone I was going to spend a full year subjecting myself to half a dozen diets. They were right. It was August 2008, the end of an intense season of bike racing, and at five foot eleven and 149 pounds, I'd crossed over into scrawny. But while pointing out the obvious, the Olsen-twin jokes and rib pokes revealed something more important: the assumption that, vegetarians and locavores aside, people change the way they eat only when they need to lose weight.
If you're thin, the thinking goes, your diet is fine. Of course, thin doesn't necessarily equal healthy. Not even when, for guys like me, it's the result of an athletic lifestyle. The reality is, many of us use our fast 10K times to excuse horrible food choices. I once saw an interviewer ask Robin Williams what he ate to keep his weight down, to which the famously bike-obsessed comic replied, "I can eat pretty much anything. I ride bikes." That's a popular attitude; sometimes the main appeal of a long ride is the beer-and-burger mayhem that follows. This may explain why a federal government survey released last summer found that heavy drinkers actually exercise more than abstainers.
At 38, with a family history of heart disease and a personal history of late-night pizza and uneven energy levels, I needed a better way. I wanted a strategy that would generate healthier eating habits without mandating strict adherence to an austere, dogmatic program. But where to start? The diet industry focused almost exclusively on overweight people for whom brisk hikes would be an improvement; there were few options for a trim, year-round athlete.
So I decided on a radical experiment. I would spend eight weeks each on six different plans representing the various options for would-be dieters, from popular fads to clinical studies: the Abs Diet, the Paleo Diet for Athletes, the Mediterranean Prescription, the Okinawa Program, the advice of a personal nutritionist, and the USDA's nutritional pyramid. I'd record every meal, snack, caloric drink, and workout, along with notes on how I was feeling, and make bimonthly visits to my doctor and the blood lab for weigh-ins, cholesterol checks, and body-composition analysis. I'd grant myself only two breaks: 19 days for my honeymoon, after the Abs Diet, and 11 days around Christmas and New Year's, after the Paleo Diet for Athletes. Huge pain in the ass. Huge.
My hypothesis: By applying the same discipline to nutrition that I apply to cycling, I'd be able to measure these diets against the claims of their authors. Each one would have something to teach me; each would also fail me. And along the way, I became the world's leading expert on how I'm supposed to eat.