No, I really don’t think most people can weigh 400lbs. My reasoning?
The New York Times references a deliberate exercise in weight gain, where prisoners increased their weight by 20 to 25 percent.
But it took them four to six months, eating as much as they could every day. Some consumed 10,000 calories a day, an amount so incredible that it would be hard to believe, were it not for the fact that there were attendants present at each meal who dutifully recorded everything the men ate. […]
When the study ended, the prisoners had no trouble losing weight. Within months, they were back to normal and effortlessly stayed there.
Their bodies resisted weight gain, and they returned back to their original weight. That’s setpoint in action. (Setpoint is also what returns you to your regular weight after you’ve lost weight with flu.)
What if someone really wants to gain weight and really works at it? Not just a few pounds for a study, but seriously intending to gain a LOT? Bodybuilders, for example, work very hard to gain weight, specifically muscle. There’s a reason that many bodybuilders use drugs to increase their gain; it’s because their genes won’t do it alone. Mitchell Rupe was famous for using his 400lb+ weight to avoid execution. Many claimed the gain was intentional, although Rupe’s lawyer stated that his weight was related to a medical condition. I note that other prisoners on death row haven’t gained weight en masse, despite the considerable carrot of escaping execution.
Ah, you wonder, what sets the setpoint? It starts with genetics.
Another study in weight gain, with twins, also found that most subjects lost the added weight after the study. In addition,
The twins in each pair gained almost exactly the same amount of weight and gained it in the same places. One pair would put most of it on in the abdomen, another in the buttocks and thighs. […]
[T]here were marked differences between the twin pairs in weight gain. The twins in the pair gaining the most each added more than 29 pounds, while the ones in the pair gaining the least each put on about nine and a half pounds. The average weight gain for the group as a whole was nearly 18 pounds […]
I also found it interesting the participants in this study were “overfed” by 84,000 calories on average. Assuming the 3,500 calories per pound figure is correct, that “should” have been a 12lb gain, not a 9lb to 29lb gain. The researchers found that not only did the amount of weight gained vary, but so did the muscle/fat ratio. Those who gained only 9lbs gained the most muscle mass, those who gained 29lbs gained the least.
In addition, twins reared apart as are likely to weigh the same – and have similar body composition – as twins reared together. Nature wins out over nurture in that respect.
But, you may be wondering, what changes a setpoint?
- Aging. People’s setpoints do tend to increase as they age.
- Activity Levels. Linda Bacon notes in Health At Every Size that people who are very active average a setpoint of 10-15lbs less than those don’t exercise regularly. (Not “lose 10lbs a year”. 10lbs less total. And she notes that research shows that obese people who increase their activity levels do not necessarily lose 10-15lbs.)
- Processed Foods. Again from Health At Every Size, the average American weighs 10-12lbs more than in the 60s. This is strongly correlated with the increase in processed foods, and has been seen in other populations as they add more processed foods to their diet.
- Medical issues. Mobility limited due to a leg break or damage to vertebrae? Limited mobility will affect your body. Get sick and need drugs that cause weight gain? You’ll gain, at least while you’re on it. Some illnesses and medical conditions cause weight gain too. But generally your body will find a new setpoint, some pounds over your old setpoint.
- Dieting. Several studies have shown that repeated “dieting [is] actually a consistent predictor of future weight gain.” I am the sort of dieter for whom weight loss is not only temporary but I regain MORE than I lost, resulting in a net gain; and I did not diet once, but repeatedly, from age 10 through age 20, and occasionally thereafter. Linda Bacon argues in Health at Every Size that our bodies stubbornly resist losing weight, but are more lenient about weight gain – especially after repeated diet attempts. It’s like the body wants to protect against these recurrent famines it keeps experiencing by building up greater reserves.
(I think that if I had not yo-yo dieted I would probably weigh less. I also can’t undo it. “Coulda, woulda, shoulda” – it don’t matter how much I say those words, it makes no difference. It doesn’t DO anything. What I can do, now, is to take care of the body I’ve got NOW.)
So, if you’ve been reading this, wondering if you, too, could gain up to 400lbs (or that you could become morbidly obese or super obese or class 3 obese or class III obese or whatever you want to call it) … weight, like height, is spread across the population in a bell curve. Just as most people are not taller than 6’6″, most just don’t weigh more than 300lbs.
Yes, if your parents and grandparents weigh above 300lbs, then your chances of weighing above 300lbs increase. If you weigh above 300lbs, then yes, it could happen. But if you’re under 250lbs, your parents are under 250lbs, your grandparents are under 250lbs, and you’re scared that you’ll start gaining and never stop?
Relax. You probably won’t.