3. It's Even More Expensive If You Started Out Fat
The body of a 120 pound woman who was always 120 pounds does not metabolize food or allocate energy the same way the body of a 120-pound woman who started off at 180 pounds. It's going to take the woman who lost a lot of weight much more exercise and more attention to maintain 120 pounds than the other one. And you don't have to lose a lot of weight for these kinds of hormonal changes to take place, either. A weight loss of just 10% of your body weight will trigger it, no matter if you started off as obese, underweight, or anywhere in between. Obviously for a slim-to-healthy-weight person, a weight loss of 10% would put them closer to underweight than is good, and those hormonal changes are incredibly beneficial, but if a 250 pound man loses 25 pounds, he is hardly in danger of being underweight. Too bad his body doesn't realize that. (See point #6 again.) What's worse is that this change is impossible to mitigate or reverse. Biopsies done on muscle tissue of people who had successfully lost weight revealed that even a year later, their muscle tissue was different than that of people at the same weight who had never dieted: in particular, the once-overweight people had more slow twitch muscle fibers, meaning that they burned fewer calories during the same workout. This is no small difference either: anywhere from 20% to 25%. Never mind that your BMR will reflect this change as well. In other words: you need fewer calories a day and burn fewer when you exert yourself. A really handy ability when your food sources run temporarily low out there on the savanna, but really freaking annoying when you're trying to drop those last 15 pounds. This effect has been observed in subjects who lost weight even six years after they had reached their goal weight. Six years! And there's no indication that even after six years your muscles and metabolism will suddenly get a clue and flip to what they would be on someone who had never lost that weight. So even if you and your brother are now the same weight and even have (somehow) more or less identical body compositions, you will still need to eat less and exercise more than him to stay the same weight. More time at the gym, more mental energy devoted to counting calories, still more decision fatigue, all for the same body your brother can maintain without a second thought.
After obtaining a BA in Philosophy and Creative Writing, Katherine spent two years and change teaching English in South Korea. Now she lives in Sweden and edits articles for Turkish science journals. When she isn't writing, editing, or working on her NaNo novel, Katherine enjoys video games, movies, and British television.
