5 ms·

The laws of thermodynamics don't change though. Calorie deficit over time will get you to lose weight. Exercise can ensure that can be done in a healthy manner

The laws of thermodynamics don't change though. Calorie deficit over time will get you to lose weight. Exercise can ensure that can be done in a healthy manner (besides hard dieting)

dan-robertson 4y ago
I think the idea that all of weight loss can be reduced to calories-in-calories-out is not favoured. A simple point is that the body can regulate its metabolism so increasing/decreasing calorie intake can just lead to a slightly higher/lower body temperature while maintaining the same weight. In some sense that metabolism counts as ‘calories out’ but the feedback loop means that you can’t easily control it independently of calorie intake.
- carom 4y ago
  It can be reduced to that with a lot of emphasis on how you reduce calories. Do you break your habits such as alcohol, sugar, and caffeine that hinder reduction? Do you cut out carbs or do keto? At the end of the day it is fewer calories, what matters is if it is sustainable. I bulked for lifting in the winter. Got to a body fat percent where I wasn't happy with how I looked. I then needed to decide to cut or continue gaining strength. This decision actually caused a lot of strife when before I realized I couldn't do both effectively. I looked at my calories and what I wanted to reduce. It didn't work well, I had a hard time tracking calories and making the correct cuts despite a simple diet. Now it is summer, it is hot, I'm not using AC. My body wants less food, I cut out rice, mostly on meat and dairy. Consistently losing weight now. I attribute it largely to the heat. My take away is that it is eating less, but eating less is hard.
- zihotki 4y ago
  The metabolic feedback loop there is not precise as you may think. There is a huge variability and even big thresholds of when it starts switching. That's why you need to measure your calories intake and results, and act accordingly. Small calories deficit won't slow down the metabolism, especially if you add a bit of excercise or physical activity to the list. Big calories deficit on the other hand could cause issues.
- n8henrie 4y ago
  This is not supported by metabolic ward studies. Metabolism per kg of lean body mass is largely maintained, the reductions in absolute basal metabolic rate during significant weight loss are almost exclusively due to having less tissue for which to provide energy.
- sn9 4y ago
  Body temperature in mammals is highly regulated and does not vary much outside of a very tight window. It's not a meaningful factor in any sort of weight change unless taking substances with dangerous side effects.
bawolff 4y ago
But starving to death is not a healthy way to lose weight.
JamesBarney 4y ago
If we had a drug that increased caloric expenditure by 5 calories but increased hunger by 500 calories, so that on average people who took it gained 10 pounds. Would you say this drug helped you lose weight? Or on the other end if you have a drug that decreases caloric expenditure by 5 calories but decreases hunger by 500 calories would you say this drug helps people gain or lose weight? We can look at these interventions through the very narrow lens of thermodynamics and say the first one will help with weight loss and the second will help with weight gain. Or we can just give people the drug and see what happens to their weight. It seems very clear to me the second approach is a better one.
layer8 4y ago
That’s not wrong, but as a counterpoint, the only way for me to lose weight is to count calories (intake), whereas just exercising doesn’t make me lose weight (presumably because then I also eat more if I don’t measure and limit how much I eat). So at least for me I’d say that restricting calorie intake is necessary for losing weight, whereas just exercising only helps in maintaining weight.

The laws of thermodynamics don't change though. Calorie deficit over time will get you to lose weight. Exercise can ensure that can be done in a healthy manner (besides hard dieting)

dan-robertson 4y ago

I think the idea that all of weight loss can be reduced to calories-in-calories-out is not favoured. A simple point is that the body can regulate its metabolism so increasing/decreasing calorie intake can just lead to a slightly higher/lower body temperature while maintaining the same weight. In some sense that metabolism counts as ‘calories out’ but the feedback loop means that you can’t easily control it independently of calorie intake.

carom 4y ago
It can be reduced to that with a lot of emphasis on how you reduce calories. Do you break your habits such as alcohol, sugar, and caffeine that hinder reduction? Do you cut out carbs or do keto? At the end of the day it is fewer calories, what matters is if it is sustainable. I bulked for lifting in the winter. Got to a body fat percent where I wasn't happy with how I looked. I then needed to decide to cut or continue gaining strength. This decision actually caused a lot of strife when before I realized I couldn't do both effectively. I looked at my calories and what I wanted to reduce. It didn't work well, I had a hard time tracking calories and making the correct cuts despite a simple diet. Now it is summer, it is hot, I'm not using AC. My body wants less food, I cut out rice, mostly on meat and dairy. Consistently losing weight now. I attribute it largely to the heat. My take away is that it is eating less, but eating less is hard.
zihotki 4y ago
The metabolic feedback loop there is not precise as you may think. There is a huge variability and even big thresholds of when it starts switching. That's why you need to measure your calories intake and results, and act accordingly. Small calories deficit won't slow down the metabolism, especially if you add a bit of excercise or physical activity to the list. Big calories deficit on the other hand could cause issues.
n8henrie 4y ago
This is not supported by metabolic ward studies. Metabolism per kg of lean body mass is largely maintained, the reductions in absolute basal metabolic rate during significant weight loss are almost exclusively due to having less tissue for which to provide energy.
sn9 4y ago
Body temperature in mammals is highly regulated and does not vary much outside of a very tight window. It's not a meaningful factor in any sort of weight change unless taking substances with dangerous side effects.

bawolff 4y ago

But starving to death is not a healthy way to lose weight.

JamesBarney 4y ago

If we had a drug that increased caloric expenditure by 5 calories but increased hunger by 500 calories, so that on average people who took it gained 10 pounds. Would you say this drug helped you lose weight? Or on the other end if you have a drug that decreases caloric expenditure by 5 calories but decreases hunger by 500 calories would you say this drug helps people gain or lose weight? We can look at these interventions through the very narrow lens of thermodynamics and say the first one will help with weight loss and the second will help with weight gain. Or we can just give people the drug and see what happens to their weight. It seems very clear to me the second approach is a better one.

layer8 4y ago

That’s not wrong, but as a counterpoint, the only way for me to lose weight is to count calories (intake), whereas just exercising doesn’t make me lose weight (presumably because then I also eat more if I don’t measure and limit how much I eat). So at least for me I’d say that restricting calorie intake is necessary for losing weight, whereas just exercising only helps in maintaining weight.