3 ms·

This actually isn’t entirely true. You’re operating under the “energy in-energy out” theory of weight loss, but human regulation of body fat is more complicated

This actually isn’t entirely true. You’re operating under the “energy in-energy out” theory of weight loss, but human regulation of body fat is more complicated than that. Specifically, we store energy in adipose tissue in the form of body fat after a meal (think of it like storing data on disk) and then when we are low on energy we burn that fat (load that data “in-memory”). However, a lot regulates when we burn fat. Blood sugar and insulin levels signal to the body not to burn fat and those come directly from carbohydrates. Additionally, carbohydrates are the initial energy source that is turned to fat. So with no carbs all your body knows how to do is burn fat for energy, and no additional intake of carbs means that there is no excess energy to store as fat to begin with. So, actually, even with a 5000 calorie diet you might see some weight loss... because your body has literally nothing (no carbs) to store as fat. However, keto and low carb diets do have the benefit of the fact that they are entirely sustainable (unless you’re really addicted to bread) so I agree in that way they are behavioral :P

superpermutat0r 7y ago
How can the body, given 5000 kcal in fat not store any of that fat in the adipose tissue?
- adamgluck 7y ago
  Your body responds to the intake of carbohydrates by creating insulin which regulates the storage of carbohydrates as “body fat” (see: glycogen). Overall, your body is 70% fat (cell membranes, for example). In other words, dietary fat != body fat and there is no reason that your body would store it as such (in adipose tissue), it actually, mechanistically, as far as I know, cannot.
  - superpermutat0r 7y ago
    But glycogen is not fat in the adipose tissue. Glycogen goes into muscles and is a ready fuel, fuel ready for fast metabolic burn. The metabolism to turn carbohydrates and protein into fat is insanely inefficient compared to just storing fat as fat. And fat is the first thing to get stored when there's an insulin spike, not to mention the carbs+fat combination is the thing that creates insulin resistance exactly because of the fat messing everything up. So I'm thinking, and please correct me if I'm wrong, that you are just repeating some keto "truth" that does not really make sense. Because when I googled that, the only sources were pretty much some keto promoting pages.
  - masonic 7y ago
    Is that a typo? Glycogen is not a lipid. Do you mean glycerol?
  - piva00 7y ago
    As other commenters have pointed out, the pathway of converting dietary fat to body fat is extremely efficient compared to the ones for carbs and proteins. The body has ways to store or convert most of the macro nutrients to fat when needed, insulin spikes help with that but aren't the only mechanism to trigger fat storage.
pen2l 7y ago
> You’re operating under the “energy in-energy out” theory of weight loss, but human regulation of body fat is more complicated than that. I hear the "energy in-energy out" being dismissed like this often, and while I do agree with you that our bodies are more complex than that, I want to say that in practice this adage more or less just works, indeed to the degree that it's valuable to have in common knowledge to inspire folks to lose fat. Particularly, if you want to lose fat, you reduce your caloric intake (and what you are consuming, shoot for higher protein intake and lower carb intake). In addition to this, do some aerobic exercises. This is really it. If you do this you're nearly guaranteed to lose fat. I did this, my peers did this, it's really simple, the only hard part is finding the motivation to start and having faithful long-term committal to a routine.
- awayfromhomenow 7y ago
  with high insulin, doing this nearly guarantees that your body will pull the calories from muscle tissue, versus pulling them from fat. So you can end up sabotaging your efforts.
- PeterisP 7y ago
  The thing is that "energy in-energy out" works if you make some changes while keeping everything else constant.... and we're really, really bad at keeping everything else constant. Add extra activity, and the natural effect will be an increased appetite that'll nudge you to eat more calories - and it's not a given the effect of that extra activity will be a calorie deficit, the increase in appetite can easily be more than what you spent in those exercises. If you try to reduce caloric intake, that's a very different beast than actually reducing caloric intake - if you try to reduce caloric intake by skipping carbs at lunch, it can result in reduced activity (so less calories out) and a strong nudge to "cheat" at other meals or snacks; and again it's plausible to get to a situation where the unintended compensation is larger (and opposite) than the behavior modification that you made. That is the problem with the "energy in-energy out" model - one does not simply change the 'energy in' or 'energy out' part and expect that other things will stay constant either magically or through sheer willpower.
JMTQp8lwXL 7y ago
One other practical aspect of this: it is largely unpalatable to eat exclusively protein and fats in large quantities. It is easy to load up on carbs.
thrwawayNutri 7y ago
>So, actually, even with a 5000 calorie diet you might see some weight loss... because your body has literally nothing (no carbs) to store as fat. I usually just lurk HN but I had to make a throwaway to respond to this unsubstantiated claim. Show me someone--who isn't a 300lb (136.1kg), 6'11" (2.11m) professional athlete who works out 3hr everyday, a morbidly obese, 600lb person at a normal height, or someone with a genetic/hormonal disorder--that loses weight on a 5000 calorie diet and I will personally send you $100 right now. I have lost weight on keto, so I understand the appeal of the diet. But that was more because I was in a calorie deficit. This idea that no carbs leads to no fat gain is a bit ridiculous. The body has multiple biological processes to create carbs, fat, and substitutes for carbs and fat. One of those processes is ketosis itself. Junk science like your claim leads to situations like a thread a few days ago in /r/fitnesscirclejerk where they found out that one of the mods in /r/keto is 400lbs.
silviogutierrez 7y ago
So, yes and no. That's why I said "primarily." It's wayyyyy more complicated than calories-in vs calories-out. But 90% of it does come down to that. More importantly though, you need to define what "calories-in" means. I like to think of a silly extreme. If I drink a gallon of gasoline, I've technically consumed what, a billion calories? But I won't gain a single gram.[1] Why? There's no metabolic pathway to convert gasoline to ATP. If you take that silly example and moderate it, you can see how different factors, including genetics, gut flora, adaptation, etc could affect what is even processed and thus part of the "in" variable. More concrete, well known examples: - If you consume 5000 calories of just protein, the metabolic pathway to convert to lipids is extremely inefficient. You will mostly excrete the excess. - Similar with pure ethanol. If you drank just alcohol (and nothing else), there is no metabolic pathway to convert this to fat. - Even carbs. If you just ate 5000 calories of pure carbs, de novo lipogenesis (metabolic pathway for carbs -> fat) is rather inefficient. You will gain weight but less than the 5000 - expenditure. A lot of it is burnt off as heat. - Sadly, for ketoers: the dietary fat to lipid pathway is extremely efficient. Almost 90% of excess will be stored as fat.[2] See a pattern here? The reality of the typical diet is that we don't just eat one macronutrient. We mix them. And specific ratios are what make food hyper palatable and thus so easy to overeat. Once you start mixing things up, it basically - and I mean basically - comes down to calories in vs calories out. [1] In fact, I would likely die. [2] As another commenter mentioned, there was one guy who just ate fat and well in excess of his BMR and apparently lost weight. I'm skeptical, but could believe it simply because it follows the trend: consuming just one can "bend" the rules.
- adamgluck 7y ago
  Would be curious about the evidence you have that dietary fat is stored as (noticeable) body fat? 70% of the body is fat. Specifically, what evidence is there that dietary fat stored in a way that makes it so that it appears as noticeable body fat and causes meaningful weight gain?
  - silviogutierrez 7y ago
    This is a great read: https://bodyrecomposition.com/fat-loss/how-we-get-fat.html/ https://bodyrecomposition.com/fat-loss/how-we-get-fat.html/ Never mind the clickbait-ey domain. Lyle McDonald is a nutrition authority and well respected. Though on forums he’s self-admittedly volatile.

superpermutat0r 7y ago

How can the body, given 5000 kcal in fat not store any of that fat in the adipose tissue?

adamgluck 7y ago
Your body responds to the intake of carbohydrates by creating insulin which regulates the storage of carbohydrates as “body fat” (see: glycogen). Overall, your body is 70% fat (cell membranes, for example). In other words, dietary fat != body fat and there is no reason that your body would store it as such (in adipose tissue), it actually, mechanistically, as far as I know, cannot.
- superpermutat0r 7y ago
  But glycogen is not fat in the adipose tissue. Glycogen goes into muscles and is a ready fuel, fuel ready for fast metabolic burn. The metabolism to turn carbohydrates and protein into fat is insanely inefficient compared to just storing fat as fat. And fat is the first thing to get stored when there's an insulin spike, not to mention the carbs+fat combination is the thing that creates insulin resistance exactly because of the fat messing everything up. So I'm thinking, and please correct me if I'm wrong, that you are just repeating some keto "truth" that does not really make sense. Because when I googled that, the only sources were pretty much some keto promoting pages.
- masonic 7y ago
  Is that a typo? Glycogen is not a lipid. Do you mean glycerol?
- piva00 7y ago
  As other commenters have pointed out, the pathway of converting dietary fat to body fat is extremely efficient compared to the ones for carbs and proteins. The body has ways to store or convert most of the macro nutrients to fat when needed, insulin spikes help with that but aren't the only mechanism to trigger fat storage.

pen2l 7y ago

> You’re operating under the “energy in-energy out” theory of weight loss, but human regulation of body fat is more complicated than that. I hear the "energy in-energy out" being dismissed like this often, and while I do agree with you that our bodies are more complex than that, I want to say that in practice this adage more or less just works, indeed to the degree that it's valuable to have in common knowledge to inspire folks to lose fat. Particularly, if you want to lose fat, you reduce your caloric intake (and what you are consuming, shoot for higher protein intake and lower carb intake). In addition to this, do some aerobic exercises. This is really it. If you do this you're nearly guaranteed to lose fat. I did this, my peers did this, it's really simple, the only hard part is finding the motivation to start and having faithful long-term committal to a routine.

awayfromhomenow 7y ago
with high insulin, doing this nearly guarantees that your body will pull the calories from muscle tissue, versus pulling them from fat. So you can end up sabotaging your efforts.
PeterisP 7y ago
The thing is that "energy in-energy out" works if you make some changes while keeping everything else constant.... and we're really, really bad at keeping everything else constant. Add extra activity, and the natural effect will be an increased appetite that'll nudge you to eat more calories - and it's not a given the effect of that extra activity will be a calorie deficit, the increase in appetite can easily be more than what you spent in those exercises. If you try to reduce caloric intake, that's a very different beast than actually reducing caloric intake - if you try to reduce caloric intake by skipping carbs at lunch, it can result in reduced activity (so less calories out) and a strong nudge to "cheat" at other meals or snacks; and again it's plausible to get to a situation where the unintended compensation is larger (and opposite) than the behavior modification that you made. That is the problem with the "energy in-energy out" model - one does not simply change the 'energy in' or 'energy out' part and expect that other things will stay constant either magically or through sheer willpower.

JMTQp8lwXL 7y ago

One other practical aspect of this: it is largely unpalatable to eat exclusively protein and fats in large quantities. It is easy to load up on carbs.

thrwawayNutri 7y ago

>So, actually, even with a 5000 calorie diet you might see some weight loss... because your body has literally nothing (no carbs) to store as fat. I usually just lurk HN but I had to make a throwaway to respond to this unsubstantiated claim. Show me someone--who isn't a 300lb (136.1kg), 6'11" (2.11m) professional athlete who works out 3hr everyday, a morbidly obese, 600lb person at a normal height, or someone with a genetic/hormonal disorder--that loses weight on a 5000 calorie diet and I will personally send you $100 right now. I have lost weight on keto, so I understand the appeal of the diet. But that was more because I was in a calorie deficit. This idea that no carbs leads to no fat gain is a bit ridiculous. The body has multiple biological processes to create carbs, fat, and substitutes for carbs and fat. One of those processes is ketosis itself. Junk science like your claim leads to situations like a thread a few days ago in /r/fitnesscirclejerk where they found out that one of the mods in /r/keto is 400lbs.

silviogutierrez 7y ago

So, yes and no. That's why I said "primarily." It's wayyyyy more complicated than calories-in vs calories-out. But 90% of it does come down to that. More importantly though, you need to define what "calories-in" means. I like to think of a silly extreme. If I drink a gallon of gasoline, I've technically consumed what, a billion calories? But I won't gain a single gram.[1] Why? There's no metabolic pathway to convert gasoline to ATP. If you take that silly example and moderate it, you can see how different factors, including genetics, gut flora, adaptation, etc could affect what is even processed and thus part of the "in" variable. More concrete, well known examples: - If you consume 5000 calories of just protein, the metabolic pathway to convert to lipids is extremely inefficient. You will mostly excrete the excess. - Similar with pure ethanol. If you drank just alcohol (and nothing else), there is no metabolic pathway to convert this to fat. - Even carbs. If you just ate 5000 calories of pure carbs, de novo lipogenesis (metabolic pathway for carbs -> fat) is rather inefficient. You will gain weight but less than the 5000 - expenditure. A lot of it is burnt off as heat. - Sadly, for ketoers: the dietary fat to lipid pathway is extremely efficient. Almost 90% of excess will be stored as fat.[2] See a pattern here? The reality of the typical diet is that we don't just eat one macronutrient. We mix them. And specific ratios are what make food hyper palatable and thus so easy to overeat. Once you start mixing things up, it basically - and I mean basically - comes down to calories in vs calories out. [1] In fact, I would likely die. [2] As another commenter mentioned, there was one guy who just ate fat and well in excess of his BMR and apparently lost weight. I'm skeptical, but could believe it simply because it follows the trend: consuming just one can "bend" the rules.

adamgluck 7y ago
Would be curious about the evidence you have that dietary fat is stored as (noticeable) body fat? 70% of the body is fat. Specifically, what evidence is there that dietary fat stored in a way that makes it so that it appears as noticeable body fat and causes meaningful weight gain?
- silviogutierrez 7y ago
  This is a great read: https://bodyrecomposition.com/fat-loss/how-we-get-fat.html/ https://bodyrecomposition.com/fat-loss/how-we-get-fat.html/ Never mind the clickbait-ey domain. Lyle McDonald is a nutrition authority and well respected. Though on forums he’s self-admittedly volatile.