If it's Tour de France time, it's time for blog posts on how amazingly much the racers eat per day: about 5,900 for an average stage, which entails anywhere from four to six hours of riding, and up to about 9,000 for one of the tough mountain stages, like this year's "queen stage," number 17, a 210.5km stretch from Embrun to l'Alpe d'Huez.
A "normal" male of my size and age - and I'm a bit bigger and a bit older than the average Tour racer - should eat about 2,200 to 2,500 calories a day, so the average tour rider - who's a bit shorter, thinner, and younger than me - is eating anywhere from 100% to 350% more calories.
And this isn't easy to do, as the guys at Science of Sport show. Since a rider is "occupied for up to 16 hours a day with riding, sleeping, and other activities, he has only about 7-8 h[ours] to ingest 5500 calories, which works out to about 700+ calories an hour during the time he is available to eat and drink." That's a lot of intense chowing. (For comparison, a Big Mac packs about 540 calories - but not many elite athletes are going to eat Big Macs to catch up on their calories.)
Though I cannot (or need to) eat at quite that rate, anyone who's ever had a meal with me - or tried to feed me - might know that I can on occasion eat quite a bit of food, especially relative to my relentlessly average height and weight. And yet I'm almost always hungry: my stomach starts growling within an hour of finishing any given meal, even if I've taken pains to eat thirds of the heaviest fare. Part of this is that I must have a pretty high natural metabolic rate; another part must be that my metabolism is in high gear thanks to relatively regular workouts. I've long suspected that the "normal" number of calories for a guy like me - 2,500 - isn't sufficient.
Following a link from another story about the Tour de France, I recently came some decent evidence to bear this out: a webpage that helps determine a person's "energy expenditure," which is basically how many calories (okay, kilocalories - I know at least one dietitian who might be reading this) are needed to sustain a certain level of daily activity. To help calculate that energy expenditure, the site offers an "easy" method (weight multiplied by a certain factor - such as 20 for "active people" working out 5-7 times a week) and an "accurate" method (calculating and then adding together the basal metabolic rate, the energy expended during physical activity, and the thermic effect of using energy for digestion).
Running each method, I came out with a total caloric need that's a good 500 kcal above the "norm" for an adult male and thus way above the guidelines I've been using (serving sizes as listed on the side of food containers, for instance). Oops. That 20% margin of error probably explains why I am, even as I finish this post, seriously considering a second dinner.