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The biggest losers: Metabolic damage or constrained energy?

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Re: The biggest losers: Metabolic damage or constrained energy?

#51

Post by arcticbull »

slothtrop wrote: post #30

The more frequent the dieting and steeper the caloric deficit, the worse metabolic adaptation gets, and the longer it takes to return to normal. As I understand it that's the result discerned from more than just one paper. Layne Norton explores this at length in his book Fat Loss Forever and yt channel. The interesting thing in this link was the impact of change in exercise regimen. We know that exercise in itself ca…

> It's possible to lose weight sustainably even without exercise, so perhaps it's fair to say that if you're going to exercise, you best sustain it.

Exercise is for muscle gain and general health, not for weight loss. You have to exercise a truly absurd about to burn enough calories to lose any meaningful amount of weight. You'd have to run from SF to LA to lose 10lbs, and that's assuming you eat nothing else to compensate which humans are notorious for doing. Your body has a very strong homeostatic drive, and will absolutely push you to eat more and to be more sedentary outside of work-out time to compensate for any additional exercise you do.

There's no studies or evidence whatsoever that shows it has a meaningful impact on weight loss. Weight loss comes from what you put in (or rather don't).

This write-up from 2016 references 60 studies and meta-analysis which all show the same. [1]

tl;dr: you should exercise for health and for muscle gain, not for weight loss.

[edit] Note that metabolic adaptation results from caloric restriction dieting too, which is why 95% of diets fail. Basically only GLP-1s and gastric bypass have been clinically shown to result in meaningful, sustained, long-term weight loss. Obesity is a dysfunction of the gabaergic central nervous system. That's why everyone's so excited about GLP-1s.

[1] https://www.vox.com/2016/4/28/11518804/weight-loss-exercise-...

Re: The biggest losers: Metabolic damage or constrained energy?

#52

Post by tech_ken »

belltaco wrote: post #6

> In 2016, Pontzer and colleagues published a study putting forward the constrained energy model: Energy expenditure does increase with more activity, but only to a point. Once physical activity gets really high, the body will adjust other components of the metabolism to keep your daily energy expenditure within a narrow range How do people who constantly repeat the mantra of thermodynamics in such threads explain th…

Seems in line with other phenomena such as resting heart rate decreasing after sustained cardio training regimens. Your body just starts expending less energy during resting periods. This doesn't entail loss of function because the body is capable of operating in a wide variety of energy expenditure regimes

Re: The biggest losers: Metabolic damage or constrained energy?

#53

Post by bodiekane »

thaanpaa wrote: post #18
SV_BubbleTime wrote: post #3

Earlier quoted context omitted.

I don’t understand how this needs anything beyond surface level complexity… you have fat people who for show reasons were tightly controlled on exercise and food intake - which works for well understood reasons - then they took that away and left the people to their lifelong established habits. Of course they regain the weight. These people didn’t magically create mass from nothing. They ate too much for their activi…

It requires that complexity because a metric shit ton of scientific research shows that it is more complicated than that. Permanent weight loss of more than ten pounds is nearly impossible from a scientific standpoint. The success rate after 5 years of weight loss is somewhere around 0.1%. You'd think that if it was as easy as everyone claims, more people would succeed. Heck, many people who have had gastric bypass s…

My weight floats in a range that's 40-50 pounds lighter today than I was a decade ago. It's because I eat less and move more.

Physically, weight-loss is utterly trivial. Literally everything that people say works, does. Eat less calories, eat less sugar, cut out snacking, cut out liquid calories, cut out processed food, reduce carbs, literally any and all of those work, choose whichever is most appealing to the individual.

The challenge to weight and diet in America is mental and cultural. Obese people remain obese because they have unhealthy relationships with food and eat addictively or emotionally, using food to soothe anxiety, depression, loneliness, disappointment, etc and because cultural norms and advertising have normalized obesity-causing diets.

Eat food. Not too much. Mostly plants.

Re: The biggest losers: Metabolic damage or constrained energy?

#54

Post by bluGill »

belltaco wrote: post #6

> In 2016, Pontzer and colleagues published a study putting forward the constrained energy model: Energy expenditure does increase with more activity, but only to a point. Once physical activity gets really high, the body will adjust other components of the metabolism to keep your daily energy expenditure within a narrow range How do people who constantly repeat the mantra of thermodynamics in such threads explain th…

Most people who quote thermodynamics don't understand it. They are just saying calories in = calories turned to fat + calories burned. Which is true, but not helpful. The body has many choices, including burning it and then using sweat to get rid of the extra heat. Since we have minimal control over if the body will do this there isn't anything more thermodynamics can input into weight.

Re: The biggest losers: Metabolic damage or constrained energy?

#55

Post by slothtrop »

arcticbull wrote: post #51
slothtrop wrote: post #30

The more frequent the dieting and steeper the caloric deficit, the worse metabolic adaptation gets, and the longer it takes to return to normal. As I understand it that's the result discerned from more than just one paper. Layne Norton explores this at length in his book Fat Loss Forever and yt channel. The interesting thing in this link was the impact of change in exercise regimen. We know that exercise in itself ca…

> It's possible to lose weight sustainably even without exercise, so perhaps it's fair to say that if you're going to exercise, you best sustain it. Exercise is for muscle gain and general health, not for weight loss. You have to exercise a truly absurd about to burn enough calories to lose any meaningful amount of weight. You'd have to run from SF to LA to lose 10lbs, and that's assuming you eat nothing else to comp…

You're confusing things. The real gains qua WL from exercise are what is lost from resting metabolic rate, not calories burned "during" exercise. Also: satiety, and other health benefits that have an impact.

> There's no studies or evidence whatsoever that shows it has a meaningful impact on weight loss.

Absolutely not true.

> Weight loss comes from what you put in (or rather don't).

It's energy balance. But just as increasing satiety helps (through food choices), exercise is a strong predictor of long-term WL success.

> This write-up from 2016 references 60 studies and meta-analysis which all show the same.

You're quoting a vox article, and it's making the aforementioned erroneous conflation about calories burned during exercise.

Re: The biggest losers: Metabolic damage or constrained energy?

#56

Post by arcticbull »

slothtrop wrote: post #55
arcticbull wrote: post #51

Earlier quoted context omitted.

> It's possible to lose weight sustainably even without exercise, so perhaps it's fair to say that if you're going to exercise, you best sustain it. Exercise is for muscle gain and general health, not for weight loss. You have to exercise a truly absurd about to burn enough calories to lose any meaningful amount of weight. You'd have to run from SF to LA to lose 10lbs, and that's assuming you eat nothing else to comp…

You're confusing things. The real gains qua WL from exercise are what is lost from resting metabolic rate, not calories burned "during" exercise. Also: satiety, and other health benefits that have an impact. > There's no studies or evidence whatsoever that shows it has a meaningful impact on weight loss. Absolutely not true. > Weight loss comes from what you put in (or rather don't). It's energy balance. But just as…

> Absolutely not true.

Please cite a study that shows that exercise results in long-term sustained, clinically meaningful (>5%) weight loss. I have looked extensively and found none. And that's not for a lack of extant studies.

> It's energy balance. But just as increasing satiety helps (through food choices), exercise is a strong predictor of long-term WL success.

As far as I can see, there aren't any successful long-term (>2y) weight loss studies that don't involve GLP-1s or bariatric surgery, so maybe that's where the issue lies.

> You're quoting a vox article, and it's making the aforementioned erroneous conflation about calories burned during exercise.

I don't think it is, I looked over the studies they link to, but I'm open to being wrong. I don't really have a horse in this race.

Re: The biggest losers: Metabolic damage or constrained energy?

#57

Post by pi-e-sigma »

awfulneutral wrote: post #33
pi-e-sigma wrote: post #21

Earlier quoted context omitted.

The only plausible explanation is that it's at a cost of other functions that are vital long-term but can be turned down temporarily? Such as reduced creation of new blood cells etc.

Couldn't your body burn more or fewer calories passively and release the energy as heat? Or you could make more or fewer micro movements throughout the day, in a way that adds up to whatever your body thinks energy expenditure should be?

Lowering body temperature would be precisely one of these things you can do short term to maintain the same calories expenditure but would be unhealthy if prolonged.

Re: The biggest losers: Metabolic damage or constrained energy?

#58

Post by waterheater »

A shift in understanding the metabolism has been gradually occurring since the 1990s with the isolation of leptin.

What is leptin? Discovered in 1994, leptin is a hormone that signals the availability of energy reserves in the body. "High leptin levels are interpreted by the brain that energy reserves are high, whereas low leptin levels indicate that energy reserves are low", the latter causing the body to enter a resource-minimizing starvation mode [1]. More recently, leptin has also been shown to regulate "neuroendocrine and immune function and [play] a role in development" [2].

Why is leptin so important to obesity? "Most obesity occurs in the presence of increased leptin levels", which suggests a form of "leptin resistance" in obese individuals [2].

Leptin changes our understanding of body fat, also called adipose tissue. We generally think of body fat as simply stored energy reserves, so fat can be burned by decreasing our caloric intake (diet) and increasing our energy usage (exercise), forcing our body to dip into its reserves. This approach is generally referred to the calorie-in/calorie-out (CICO) model. While true to an extent, this perspective is too simplistic, given one key fact: leptin is primarily produced in adipose tissue [1]. This fact means body fat is actually an endocrine system organ.

Consider this: an obese individual has elevated leptin levels. A decrease in adipose tissue causes a decrease in their leptin production. Due to leptin resistance, low leptin levels causes the body to enter starvation mode, and hardcore dieting causes leptin levels to drop further, which makes weight loss even more difficult. What they mean by "metabolic adaptation" may be understood as "leptin adaptation", though I'm just speculating there.

It's strange that so many articles talk about weight loss and "metabolism adaptation" without mentioning the hormone signalling energy availability. With leptin, we clearly see the body has an energy availability feedback loop, and fighting the intrinsic dynamics of a feedback loop rarely leads to good outcomes.

On this vein, I want to highlight slothtrap's comments:

>The more frequent the dieting and steeper the caloric deficit, the worse metabolic adaptation gets, and the longer it takes to return to normal.

>I wonder if those who sustained higher levels of exercise were actually in a steeper caloric deficit.

>perhaps it's fair to say that if you're going to exercise, you best sustain it.

These comments align with present understanding of leptin dynamics. A steep caloric deficit pushes the obese body into starvation mode, so net energy expenditure from high levels of exercise will be decreased. Weight loss will be maintained once the body adjusts its leptin production and usage, which, as of now, can only be accomplished with habit.

It's also worth mentioning here the hormone ghrelin, which was identified in 1999 and is nicknamed the "hunger hormone" [3].

[1] https://en.wikipedia.org/wiki/Leptin

[2] DOI: 10.1146/annurev.physiol.62.1.413

[3] https://en.wikipedia.org/wiki/Ghrelin

Re: The biggest losers: Metabolic damage or constrained energy?

#59

Post by vkazanov »

thaanpaa wrote: post #18
SV_BubbleTime wrote: post #3

Earlier quoted context omitted.

I don’t understand how this needs anything beyond surface level complexity… you have fat people who for show reasons were tightly controlled on exercise and food intake - which works for well understood reasons - then they took that away and left the people to their lifelong established habits. Of course they regain the weight. These people didn’t magically create mass from nothing. They ate too much for their activi…

It requires that complexity because a metric shit ton of scientific research shows that it is more complicated than that. Permanent weight loss of more than ten pounds is nearly impossible from a scientific standpoint. The success rate after 5 years of weight loss is somewhere around 0.1%. You'd think that if it was as easy as everyone claims, more people would succeed. Heck, many people who have had gastric bypass s…

I understand that you don't mean 10 pounds in a strict sense but even 20 pounds is an easily achievable and sustainable goal for fellow overweight 40-something HN readers.

It doesn't take more than restricted calorie intake and moderate excercise (walking, gym, etc). After a few cycles of gain/loss it becomes easier food consumption habits change

Re: The biggest losers: Metabolic damage or constrained energy?

#60

Post by paulpauper »

frankus wrote: post #41
SV_BubbleTime wrote: post #3

Earlier quoted context omitted.

I don’t understand how this needs anything beyond surface level complexity… you have fat people who for show reasons were tightly controlled on exercise and food intake - which works for well understood reasons - then they took that away and left the people to their lifelong established habits. Of course they regain the weight. These people didn’t magically create mass from nothing. They ate too much for their activi…

Do you have first-hand experience with being overweight and/or losing a significant amount of weight? I think you're vastly overestimating how much of this (particularly "calories out") is under voluntary control. We're discussing an article that showed that extra active calories burned tend to lead to a compensatory reduction in resting metabolism. And there are some very strong psychological/physiological drives th…

yup. many of these people who are on weight loss drugs already tried dieting and it did not work.
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