You don't really need to be obsessed though, you just need to be willing to commit to an appropriate caloric intake. You might need to look at boxes for a while to see how many calories are in your favorite foods, and you might even need to cut some of them out, but after a month or two you just kind of know what you can and can't eat, no unhealthy obsession required.

Calories, although the simplicity of the thermodynamics analogy seems simple are not the only factor at play here.

The basic reason is that your body can increase or decreased its energy expenditure drastically in response to increased or decrease consumption of calories.

I'm reading The Obesity Code by Dr. Jason Fung right now and he presents a very strong argument that the cause of obesity is insulin resistance.

In the book he cites both overfeeding studies where subjects were fed very large numbers of calories but did not gain weight, as well underfeeding studies where subjects ate only 500 calories a day but didn't lose weight.

After reading this I'm pretty damn convinced that the diet problems facing us are: highly refined carbohydrates, sugar and sugar substitutes, and alcohol (I haven't come across this in his work, but if you look at the stuff by Dr. Lustig you'll see sugar and alcohol are incredibly similar metabolically)

Think about this: for most of human history we did not count calories and yet we were not obese.

It's the highly processed western diet of breads, cakes, cereals, soda, etc that are the culprit.

I don't know. I read and really enjoyed this book, and even follow a mild version of intermittent fasting for a while. (only ate 12pm-8pm for a while).

Then a few months ago I started following some fitness YouTuber's advice, which mostly boils down to "count calories and consume less calories than your body uses". I started a basic course of counting calories and eating at a deficit, and dropped ~7kg in a few months (and hopefully am still going).

It wasn't even that hard - mostly counting everything and cutting out some of the stuff that is really high in calories. I still ate fairly well, e.g. I'd eat my favorite hamburger - just would skip the fries to be under the calorie count.

Of course I've only done this for a few months and it's hard to say if my body will eventually force me to expend less energy.

I take comfort in the fact that a lot of bodybuilders go to extreme lengths to drop down in body fat, so they've done anecdotal research on this area a lot. And most of them are not following intermittent fasting, or keto, or anything like that - they're just reducing calorie intake when needed, and going up and down in weight fairly consistently.

keep in mind a lot of body builders will also do unhealthy things to reach their aesthetic goals, like steroids.

congratulations on your cut

A great book as well is The Hungry Brain by Stephan J. Guyenet. It looks at the neurology of eating, overweight and obesity, and there is a ton there. Basically, most of the popular theories (insulin, microbiome, willpower, sugar, etc.) are only a tiny bit right, and the truth is predictably holistic, mostly driven by things that are not acting under conscious control. There are of very interesting studies covered in that book.

It is physically impossible to consume 500 calories a day and not lose body weight if you are making even a basic effort to exercise. That might work for a week, it won't for 6 months.

I see he's written a book. I don't see any peer reviewed papers or actual scientific studies that have been reproduced by others.

Yes that is simply incorrect, you will lose crazy amount of weight on 500 kcal a day. Maybe it was for rodents?

I think I saw somewhere on hackernews a calculation that for only maintaining you body temp it takes 800-900 kcal. That is not even taking into account breathing, blood circulation, etc.

The book cites somewhere between 20 and 100 peer reviewed scientific papers, maybe those pages aren't available in the preview you were able to find.

I can't find the exact part of the book where he mentions the guy who ate 500 cal/day and didn't lose weight, but when I find it again I'll note it. This person did have serious hormonal issues, though. Most people of course, 500 cal a day and also exercise weight will come off, how permanently is another question.

I fail to see how in any world underweight is worse unless its a baby.

This is coping, losing weight to a target healthy weight is always good,

Wow, no, stunningly wrong.

Being underweight is highly correlated with poor health outcomes in seniors. (https://pubmed.ncbi.nlm.nih.gov/16886095/) Obesity is obviously bad there, but being underweight is just as dangerous.

"In seniors" would be the key word there. For the average American they'd be far, far better off being slightly underweight than being obese.

The parent comment was “I fail to see how in any world underweight is worse unless its a baby.”

Pretty decent chunk of the world is seniors these days.

"is highly correlated". Correlated, not caused by being underweight.

Studies on actual cause has shown the opposite (eating to the point of being underweight raising lifespan).

I was denied life insurance once because I was underweight. Maybe, statistically, it's true.

I have since gained weight and now have life insurance.

Does anyone know if the thresholds for being "overweight" and "underweight" have changed over time? I mean, with so many people getting heavier and heavier has the standard crept up so that "underweight" isn't even skinny anymore?

Typically BMI (mass/height^2), which hasn't changed.

Excluding the fact that average height has increased gradually over time.

I believe they have changed the cut-offs because they noticed that cardiovascular issues started to occur at lower BMI than previously thought.

I didn't know this. Thanks!

It was lowered in July 1998 ("overweight" was reduced to 25 from men: 27 and women: 28)

https://www.nytimes.com/1998/06/04/us/us-to-widen-its-defini...

https://well.blogs.nytimes.com/2014/04/14/a-number-that-may-...

In fact being slightly underweight is one of the only sure ways to increase your life expectancy. Restrictive calories diet.

For many healthy people, losing weight to reach a government ideal of 'healthy' means dropping useful muscle mass. Which is not good.

What. 90% of people do not have any musculature worth talking about. Where are your sources? For 99% of people losing weight will be the problem

Brings to mind the MRI scans of the thighs of an elderly athlete versus an elderly sedentary man https://www.bettermovement.org/blog/2012/use-or-lose-looks-l...

The Army Sergeant Major of the British Army is 'overweight', for example. (He's done interviews about it.) That's obviously nonsense and he doesn't need to lose any weight at all. The idea of 'overweight' is meaningless.

Is he jacked, or fat?

If he's jacked, then yes of course he doesn't need to lose weight. That is a tiny proportion of the population though.

He's jacked, but the original comment was 'losing weight to a target healthy weight is always [ALWAYS] good'. It sounds like you agree that's a false statement?

The original comment was making a generalization that was pretty fair considering that the proportion of the population that has enough muscle mass to cause them to be 'overweight' is pretty small.

Obviously "always" is wrong. Almost nothing is absolute.

> Obviously "always" is wrong.

Bingo.

Since most people are average, there is an average "healthy weight" target. Of course individually, it's really about the ratio of lean mass to fat.

If you define many as like 2% maybe.

GP said 'losing weight to a target healthy weight is always good'. 'Always' is not true.

Well, encumbering "losing weight" with a bad method like losing muscle or breakfast cocaine or cutting fat off your belly with a knife to do it isn't an attack on losing weight, but a misunderstanding of their claim.

>Sure we all know (I think) that over- (or worse under-wight) is not health.

Anorexic is not healthy. Underweight within reason is. In fact the best way we currently know to live more is to eat much less...

https://gizmodo.com/how-living-near-the-starvation-point-can...

I think there are a few parts that are more problematic:

* Most layman diet advice is awful. There is scientifically backed advice. I think most people could understand it. It seems to not be common knowledge.

* A lot of people "backseat drive" other people's diets. Since most people carry awful advice, this is extremely unhelpful in practice.

* Some people have a crab bucket mentality towards others losing weight, and almost go out of their way to sabotage.