The Calculus Diaries - Jennifer Ouellette [74]
That pig died so that we might one day zap away our deposits of unsightly cellulite. But before you throw caution to the winds and order a second helping of panang curry, or an extra-large blueberry muffin with that grande mochaccino, let me emphasize that the J-Lab experiment was merely proof of concept. We are nowhere near the point where we can indulge our food cravings and burn the resulting fat away whenever we like. Operating an FEL is expensive, as is the capital expenditure required to build one. Nor is scheduling beam time at the facility as easy as scheduling an appointment with your local liposuctionist. Commercial development of any new technology takes a great deal of time and money before it can be successfully brought to market.
We are still looking for that magic bullet for effortless weight loss. It would be wonderful to lose weight with no muss or fuss; no need to obsessively write down in a food diary the caloric content of every morsel of food that passes one’s lips; no need for specially prepared meals or supplements, elaborately orchestrated food combinations, or those telltale minute surgical scars from conventional liposuction. But there is simply no substitute for the old-fashioned method of combining a sensible diet with regular exercise to burn more calories than you consume. I guess you could call this the Thermodynamics Diet, and it has a distinct advantage over competing fad diets: It has withstood the test of time.
BURN, BABY, BURN
Lulu Hunt Peters at least had a sound scientific basis for her weight-loss approach. At the time she wrote her bestselling diet book, it had been only twenty years since chemists Wilbur Atwater and Russell Chittenden came up with the notion of measuring food as units of heat that could be produced by burning it: calories. For instance, the calories contained in five pounds of spaghetti would yield enough energy to brew a pot of coffee, while those in a single slice of cherry cheesecake would operate a light bulb for an hour and a half. If one wished to drive eighty-eight miles to visit friends or family, one would need to burn the calories contained in 217 Big Macs. (Think about that when you’re planning your next road trip, and take a moment to appreciate the energy efficiency of burning fossil fuels.) If someone consumes 2,000 calories a day, that will yield just enough energy to power a 100-watt bulb for twenty-two hours—assuming 100 percent efficient conversion, which simply isn’t possible, as Carnot discovered back in the nineteenth century.
Our bodies evolved into incredibly efficient heat engines, optimized for survival, and we require far fewer calories to function than we realize. The standard method for determining how many calories we need to consume each day is called the Harris-Benedict equation, first developed in 1919. It relies on estimating a person’s basal metabolic rate, taking into account age, gender, height, and weight, and the resulting number is then multiplied by another number designating that person’s level of activity. This would range from 1.2 for those who never exercise, to 1.9 for, say, professional athletes who exercise strenuously as much as twice a day. A 120-pound woman should consume 1,300 to 1,800 calories a day, depending on age, height, and how active she is. The average 170-pound man should consume between 1,870 and 2,550 calories a day, with the same caveats.
The Harris-Benedict equation is not a perfect method, failing to account for the fact that those with excess muscle mass will burn slightly more calories than the equation suggests, while the opposite would be true for those with excess body fat. Still, the Harris-Benedict equation can be a useful