[glenra]

> I did read that point and find it perplexing.

The "fat virus" theory would perfectly explain it. If some of our co-evolved viruses and bacteria have been making us more prone to accumulate fat and it's contagious, the lab animals caught it too. So their metabolism slows down to allow them to accumulate weight on the same diet that used to be merely sufficient for sustenance.

On a personal note: I also lost 30 pounds over 6 months once. I did it by simply counting calories (hacker's diet). And I kept the weight off for about a year. But then I gained it all back and then some within the next few years. Most people can lose weight on most diets in the short term; the real trick is losing a significant amount of weight and keeping it off in the long term. Although some people manage to do it, it's not many. How to reliably lose weight and keep it off is still basically an unsolved problem.

[svdad]

No, it isn't. Unless you're saying you gained weight again while still eating the same diet, you solved the problem, you just failed at implementing the solution.

[glenra]

A diet people consistently can't keep to doesn't constitute a solution to the problem.

It's also worth noting that people who have gained a bunch of weight and lost it have a slower metabolism than people who stayed at the same weight. The Hacker's Diet - being based on calories in/calories out - did not account for this factor. The claim it made was that you could lose weight by keeping a calorie deficit for a while, then once you've lost enough weight you could stop the deficit, go back to basically eating at the level you did before and still stay at the new weight. Which doesn't work.

Dieting seems to work because your body takes a long while to adapt to new conditions. Eventually you get hungrier and less active; progress tends to stop and reverse whether or not you keep "trying".

Temporarily losing weight is "a solved problem". But losing weight without reducing metabolism and thereby making yourself more likely to gain weight in the future, is not.

[DanBC]

> But losing weight without reducing metabolism and thereby making yourself more likely to gain weight in the future, is not.

No, it is. Getting people to do it and stick to it is unsolved.

Lifestyle change, to reduce calories and restructure meals to include correct balance of proteins, carbohydrates and fats, and to raise awareness of when food is eaten and how many calories are being eaten, is tricky. But if people do it it works.

[colomon]

You know, if your algorithm worked on the first few test cases you threw at it but after that you kept on finding holes in it, you wouldn't say it had solved the problem, would you?

12 years ago, I lost 55 pounds in six months. All I had to do was carefully monitor everything I ate and burn 1000+ calories exercising six days a week.

Thing is, that was a solution that worked very well for me when I was self-employed 30-year-old single man. It has not worked at all for me as a 42-year-old married man with a child. I don't have the time for 90 minutes of exercise every day. There is always loads of food around I shouldn't be eating. I have vastly more stress in my life than I had then. And my body very definitely reacts differently to food than it used to.

What I'm trying to say is, I found a great hack for losing weight quickly back in the day. I did not find a solution to keep my weight down in the long term.

[enraged_camel]

>>You know, if your algorithm worked on the first few test cases you threw at it but after that you kept on finding holes in it, you wouldn't say it had solved the problem, would you?

The parent said he lost 30 pounds over 6 months. This is not a "test case." He implemented the solution effectively. What he ended up doing however was to change the input variables (literally) by increasing the amount he was eating. Therefore the solution he implemented failed, and he gained the weight right back.

[glenra]

It wasn't sustainable. Maintaining enough of a calorie deficit to lose that much weight made me depressed and made it hard to do my job - I think better with more calorie consumption. So I stopped dieting for much the same reason other people stop smoking - it was having negative effects I didn't like.

(Also, the system I was following (hacker's diet) incorrectly claimed after losing the weight you wouldn't gain it back from simply returning to prior eating habits. Because it didn't account for the now well-known metabolism-lowering effect of dieting.)

[dublinben]

The long term solution to keeping your weight down is to eat at your maintenance level. If you do not eat more than your your Total Daily Energy Expenditure (TDEE), you simply will not gain weight. If you eat less than your TDEE, you will lose weight. This might not be easy, but it's pretty simple.

[glenra]

That implies TDEE doesn't change. But we know that TDEE does change when people diet. (One study found that a group of people who lost 10% of their weight through dieting had their resting metabolism decline by an average of 15%.) We don't actually know how TDEE reacts to weight loss in general - how much it declines or for how long it declines in response to a particular level of loss. We also don't know how subjective hunger levels react to weight loss.

...Other than that whatever the formulas are, they seem to make long-term loss nearly impossible for most people.

[magnusson]

>(One study found that a group of people who lost 10% of their weight through dieting had their resting metabolism decline by an average of 15%.)

Can you post a link to this study?

>We don't actually know how TDEE reacts to weight loss in general

I don't think this is something "we don't actually know." Lots of weight loss studies have been done in which energy expenditure has been carefully measured, so there's plenty of data on this.

[glenra]

Okay, this is a survey from 1998 - my google-fu was not strong enough to find one more recent:

http://fampra.oxfordjournals.org/content/16/2/196.full

Quote: "...the majority of the studies point to a reduction in short-term resting metabolic rates that is greater than can be explained by the loss of body mass or fat-free mass over the same time period. Unfortunately, there has been very little work done over the last few years regarding the duration of this phenomenon.

[...]

This is relevant for motivated patients who adhere to severe hypocaloric diets to achieve rather large weight losses. When they get to goal weight their metabolic rate is severely depressed, and they can experience almost immediate weight gain if they resume their prior higher calorie intakes. Recent studies have not continued to measure changes in resting metabolic rate for extended periods to determine whether the reductions are self-limiting. "

[aliston]

Except that the entire point of the article is that it is not "pretty simple," but quite a bit more nuanced...

[DanBC]

> How to reliably lose weight and keep it off is still basically an unsolved problem.

No, it really isn't.

"Eat less calories than you burn". It's that simple. Even if we include various viruses and bacteria that help us lose weight or help us gain weight, and we include various disorders that help us lose weight or gain weight, the answer is still "Eat less calories".

Unless of course you're saying that getting people to change behaviour, for ever, is tricky. In which case I agree with you.