Energy expenditure and obesity across the economic spectrum, McGrosky et al. 2025

[Jonathan Edwards]

The intriguing thing is that even for people who gain a lot of weight - say four stone over five years - the excess of intake is a very small percentage. Since people are of different sizes and levels of activity this small percentage is much smaller than the likely difference in requirements between people. We don't expect everyone to eat the same amount at all. The problem is eating just a bit more than that particular person needs in the context.

 

[Trish]

I don't think we can ignore other factors than calorie intake. Calorie expenditure matters too. Someone who moves about more, even if they don't think of it as 'exercise' and someone who spend more time in cold environments so needs to use energy to retain body heat can gain or lose weight without changing their diet.

I have had to cut back my intake as my ME/CFS has become more severe and I can't move around as much as when well. According to my Fitbit, I'm burning about 1,100 calories a day. Less on crash days. When I was younger and fitter before ME/CFS that was a slimming diet.

At the extremes like endurance sports and polar explorers, calorie needs are huge. Tour de France male cyclists need to stuff in 6000 calories a day and have detailed diet and energy tracking by their teams.

But even comparing 2 people who seem to have the same calorie consumption and similar lifestyle may vary greatly in actual activity and exposure to cold.

On a different angle, I never blame people who can't stick to reduced calorie diets, as I've been there myself at various phases in my life where the harder I tried to diet, the more difficult and depressing it became. It's a complicated issue.

 

[Jonathan Edwards]

I don't think we can ignore other factors than calorie intake. Calorie expenditure matters too.

Yes, that is the equation. One has to equal the other. And weight gain is always due to a slight excess of intake over the needs at the time for that person.

But even comparing 2 people who seem to have the same calorie consumption and similar lifestyle may vary greatly in actual activity and exposure to cold.

So we shouldn't even start comparing two people. All that matters is the needs of the person in question.

On a different angle, I never blame people who can't stick to reduced calorie diets

I wouldn't want to blame people, but there is no need to go there. The problem I see is raising arguments that can be interpreted as meaning that deliberately limiting food intake is not the key to the solution. The exercise people do this. They tell people that to lose weight they should go out and exercise. There is no point unless you also limit your intake in the context.

The problem is a very slight imbalance on the homeostatic control mechanism for some people. Unless you override that it will simply respond to exercise by calling for more food. If you go on a hiking holiday where the food comes in rations that works but going to exercise classes once a week, or running round the park every evening will achieve nothing without deliberate limitation when you get home.

We constantly see articles in the Guardian saying that overweight is not about eating more than you need. It is unfair to suggest that because it isn't true and it encourages people to follow habits that will get them nowhere.

 

[Utsikt]

Losing weight and maintaining weight loss isn’t a one and done thing. It’s for the rest of your life.

Eating more than you have reason to believe that you need will never lead to lasting weight loss. It simply isn’t an option.

It’s incredibly demotivating to not lose weight when you restrict your calorie intake, and it’s incredibly difficult to essentially permanently change every aspect of your life because food is so ingrained in it and the social fabric.

But it is the only option that even has a chance or succeeding. Even if there are some metabolic factors that substantially lowers the calorie need for some, eating more than you’d normally need will guarantee a failure to lose weight. It’s an absolute requirement.

Without any further comparison, you can’t just quit hard drugs for a few month or years. You have to quite them for the rest of your life. Excessive food intake is no different and maybe equally challenging.

Which is why I believe that the focus on weight in the shorter term is misguided. The focus should be on maintaining a sustainable calorie intake and finding ways to make that work with your life (society needs to make that easier to achieve). And whatever happens happens wrt weight.

Unless we have studies over 5-10 years with perfect control over the food eaten that shows that they maintain the same weight when they were supposed to be in a not insignificant deficit, we can’t say that healthy weight loss isn’t possible.

It makes sense from an evolutionary standpoint that the body will try to preserve its energy reserves for as long as possible. But does it make sense that the energy reserves can’t eventually be used?

 

[jnmaciuch]

Losing weight and maintaining weight loss isn’t a one and done thing. It’s for the rest of your life.

Eating more than you have reason to believe that you need will never lead to lasting weight loss. It simply isn’t an option.

It’s incredibly demotivating to not lose weight when you restrict your calorie intake, and it’s incredibly difficult to essentially permanently change every aspect of your life because food is so ingrained in it and the social fabric.

But it is the only option that even has a chance or succeeding. Even if there are some metabolic factors that substantially lowers the calorie need for some, eating more than you’d normally need will guarantee a failure to lose weight. It’s an absolute requirement.

Without any further comparison, you can’t just quit hard drugs for a few month or years. You have to quite them for the rest of your life. Excessive food intake is no different and maybe equally challenging.

Which is why I believe that the focus on weight in the shorter term is misguided. The focus should be on maintaining a sustainable calorie intake and finding ways to make that work with your life (society needs to make that easier to achieve). And whatever happens happens wrt weight.

Unless we have studies over 5-10 years with perfect control over the food eaten that shows that they maintain the same weight when they were supposed to be in a not insignificant deficit, we can’t say that healthy weight loss isn’t possible.

It makes sense from an evolutionary standpoint that the body will try to preserve its energy reserves for as long as possible. But does it make sense that the energy reserves can’t eventually be used?

It’s a pervasive and unfalsifiable paradigm—tell someone all the things you’ve done to try to lose weight, and they will tell you that you forgot to account for calories somewhere. It’s so easy to miss some things, after all. Spend years doing diligent calorie counts, and they will doubt the truth of those numbers. Or tell you that the problem is exactly which foods you cut out this time around and you must have incurred a nutrient deficiency and taken supplements. Or that you have to do it for 5 years instead of 3 to see any results. Have someone follow you around 24/7 to double check your calorie counting, and when you’re still at the same weight they will accuse you of being a secret eater. And through all this they’ll tell you that they don’t blame you for being fat, it’s so hard to diet after all, but there’s simply no way that the truism about calorie restriction always leading to sustainable weight loss is incorrect.

If one is absolutely certain that their paradigm is correct, it’s always possible to blame the patient (even indirectly with no awareness that this is what they are doing) and come up with an alternative explanation for the contradictory evidence. Which is a pattern that we should all recognize from a different context.

 

[Utsikt]

I would like to see tested for years in a controlled trial. Will someone eventually have a lower fat percentage (I’m assuming that’s the weight we want to lose) if they stay at the lowest sustainable calorie intake for a very, very long time?

In other words, are the metabolic shifts, etc. permanent or just long lasting? So will it eventually lead to a deficit or not?

 

[Trish]

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