5 ms·

And good for getting rid of lean body mass...

by sdze 4y ago

_0w8t 4y ago
Fasting is not malnutrition. A typical human even lean one has enough fat to survive without food for 30-40 days without significant loss of lean mass. This sets us quite apart of other animals including apes. One starts to loose lean mass during prolonged calorie deficit which takes months.
- sdze 4y ago
  But in clinical trials they found that even intermittent fasting leads to LBM loss. > https://www.hawaii.edu/news/2020/10/09/intermittent-fasting-study/ https://www.hawaii.edu/news/2020/10/09/intermittent-fasting-... Considering Body Builders don’t fast, I tend to believe the study.
  - raspberry1337 4y ago
    >Considering Body Builders don’t fast, I tend to believe the study. There's entire bodybuilding schools (such as LeanGains) that build on intermittent fasting, and its increasingly more common when it comes to cutting fat. Where did you hear this?
  - virtual_void 4y ago
    Body builders don’t fast therefore fasting reduces lean body mass?
  - vidarh 4y ago
    Having done IF while lifting, the issue that stands out to me with this study is that it tested only IF with no advice on exercise or nutrition. Yes, if you fast without exercise, you will almost certainly lose muscle. And if you fast without nutritional changes, you likely won't lose much, because IF on its own does not equal a deficit over more than hours at a time. I gained muscle on IF with ease, and I also lost far more than in their study, with ease. I'm surprised, given the constraints of the study, that there was an average loss at all.
  - _0w8t 4y ago
    The study run for 3 months and people were under calorie deficit, which is typical time scale when the lean mass starts to shrink. In general intermittent fast is not a good way to loose fat precisely for this point. In Russia there are fasting resorts where people do not eat for 2-3 weeks under medical supervision. Most people do it not to loose weight but try to improve various medical conditions. Those who go there for weight loss typically gain the weight back since they do not change their eating habits. As for bodybuilders they do intermittent fasting but not to loose fat but to gain muscles. For some people this works as long as they eat sufficient calories.
  - lm28469 4y ago
    > The study only included recommendations to the timing of food intake and did not provide recommendations for calorie and macronutrient intake or physical activity. > 116 overweight and obese participants Yeah I mean IF isn't magic. If you sit in front of netflix and eat three 800cal bags of chips it doesn't matter much if you're doing IF or not. I'm doing IF for years and go to the gym every other day, most of the time fasted. I made good progress, lost fat, gained muscles, and most importantly I feel amazing. Eating schedule is only a part of the equation. You still need to eat proper food and exercise.
- Lio 4y ago
  As I understand it, based on books such as Faster[1] by Michael Hutchinson, it depends on the intensity of what you do. At low intensity exercise you can just burn just fat. The body can only get so much energy from fat in a given time, so at higher intensity levels it will try to get energy from both fat and stored carbohydrates. Once you run out of easily available carbs it will try to supplement energy from the next available store, which is protein. i.e. muscle. So this will happen well before you run out of body fat. You can apparently increase the amount of base energy you can get from fat by training cell mitochondria with lots of low internet exercise. Eg lots and lots of zone 1 or 2 on the Coggan zone system. 1. http://www.michaelhutchinson.co.uk/faster.html http://www.michaelhutchinson.co.uk/faster.html
  - TimSchumann 4y ago
    This is actually my understanding of it as well, though I kind of arrived at the conclusion on my own pulling from various sources and experience. People think about fat as if they have access to it all, but it's a surface area per unit time problem. Like all the chemistry in life, on some level, it's diffusion limited. What you should be thinking about while fasting is not letting your basal rate/time + exercise expenditure/time exceed your total energy available/time. I got pretty good at estimating this, but I wish there were an easy way to measure it. Everything is stream processing, not discrete units.
    - beagle3 4y ago
      The missing part in your description, to the best of my understanding, is fat to ketone conversion - you don’t use the fat directly, the process takes time, so ketones have to already be circulating when you need them. It can also explain why ketogenic diets work for many people - if you exercise every few days, your body will maintain sufficient blood ketone level for your exercise days, but unlike glucose, ketones that are not used get peed out eventually (and not stored/converted back to fat). Couldn’t find anyone knowledgeable enough to confirm I am right, but also no one to tell me I’m obviously wrong - still looking for one of those answers.
      - 4y ago
alecco 4y ago
That's controlled by total calories. Fasting improves body composition for diets with the same macros.
no1lives4ever 4y ago
I did a 7 day fast, and I mostly ended up losing fat. While I did not do any scientific measurement, i was able to exercise the same post the 7 day fast and my belly fat came down big time. Maybe body builders lose lean body mass when they fast, but it does not seem to hold true for the average human.
- sdze 4y ago
  You have mostly lost water to be precise. As well as muscle. You need an expensive Dual-energy X-ray absorptiometry scan in order to precisely tell the body mass composition.
  - aenis 4y ago
    How would you know, without the "expensive" densitometry scan? My anecdotal experience: I lost weight via alternate day fasting and did indeed shell out the 120 euro that two scans cost me. I lost mainly fat, my lean body mass after 6 months was down 4 pct, within error range I'd assume. I worked out normally through the entire period and even did things like a 200km bike trip during a 72hr fast. (I did a few of those to compensate for not fasting on holidays). Great experience, never felt better tbh. One thing I think I learned was the exact threshold of power that allowed me to keep burning fat. Its hard to describe the feeling but after doing this for months (over a year by now) I think I know exactly when I can still push and continue on fat, and when I need to slow down to prevent lbm loss. Doing sprints, short intervals etc. would likely cause me to break proteins in the body and indeed be counterproductive - but here more research is probably needed, and individuals will likely have different thresholds.
  - hsn915 4y ago
    Why would the body shed water instead of tapping into stored fat when there's no external energy coming it? This is delusional.
  - orangepurple 4y ago
    If you can't get a DEXA scan there is an equation published in December of 2021 which approximates it well: The new equation [%BFNew = 6.083 + (0.143 × SSnew) - (12.058 × sex) - (0.150 × age) - (0.233 × body mass index) + (0.256 × waist) + (0.162 × sex × age)] explained a significant proportion of variance in %BF5C (R2 = 0.775, SEE = 4.0%). Predictors included sum of skinfolds (SSnew, midaxillary, triceps, and thigh) and waist circumference. The new equation cross-validated well against %BF5C when compared with other existing equations, producing a large intraclass correlation coefficient (0.90), small mean bias and limits of agreement (0.4% ± 8.6%), and small measures of error (SEE = 2.5%). Generalized Equations for Predicting Percent Body Fat from Anthropometric Measures Using a Criterion Five-Compartment Model Zackary S Cicone, Brett S Nickerson 1, Youn-Jeng Choi 2, Clifton J Holmes 3, Bjoern Hornikel 4, Michael V Fedewa 4, Michael R Esco 4 Affiliations expand PMID: 34310492 PMCID: PMC8785250 (available on 2022-12-01) DOI: 10.1249/MSS.0000000000002754 https://pubmed.ncbi.nlm.nih.gov/34310492/ https://pubmed.ncbi.nlm.nih.gov/34310492/
ycombinete 4y ago
More like visceral fat
orangepurple 4y ago
Completely incorrect. Time-restricted eating and concurrent exercise training reduces fat mass and increases lean mass in overweight and obese adults https://pubmed.ncbi.nlm.nih.gov/34042299/ https://pubmed.ncbi.nlm.nih.gov/34042299/
- TimSchumann 4y ago
  Agree. I notice zero lean body mass loss while fasting. At least no more than I would just sitting on the couch doing nothing.

And good for getting rid of lean body mass...

by sdze 4y ago

And good for getting rid of lean body mass...

Fasting is not malnutrition. A typical human even lean one has enough fat to survive without food for 30-40 days without significant loss of lean mass. This sets us quite apart of other animals including apes. One starts to loose lean mass during prolonged calorie deficit which takes months.

sdze 4y ago
But in clinical trials they found that even intermittent fasting leads to LBM loss. > https://www.hawaii.edu/news/2020/10/09/intermittent-fasting-study/ https://www.hawaii.edu/news/2020/10/09/intermittent-fasting-... Considering Body Builders don’t fast, I tend to believe the study.
- raspberry1337 4y ago
  >Considering Body Builders don’t fast, I tend to believe the study. There's entire bodybuilding schools (such as LeanGains) that build on intermittent fasting, and its increasingly more common when it comes to cutting fat. Where did you hear this?
- virtual_void 4y ago
  Body builders don’t fast therefore fasting reduces lean body mass?
- vidarh 4y ago
  Having done IF while lifting, the issue that stands out to me with this study is that it tested only IF with no advice on exercise or nutrition. Yes, if you fast without exercise, you will almost certainly lose muscle. And if you fast without nutritional changes, you likely won't lose much, because IF on its own does not equal a deficit over more than hours at a time. I gained muscle on IF with ease, and I also lost far more than in their study, with ease. I'm surprised, given the constraints of the study, that there was an average loss at all.
- _0w8t 4y ago
  The study run for 3 months and people were under calorie deficit, which is typical time scale when the lean mass starts to shrink. In general intermittent fast is not a good way to loose fat precisely for this point. In Russia there are fasting resorts where people do not eat for 2-3 weeks under medical supervision. Most people do it not to loose weight but try to improve various medical conditions. Those who go there for weight loss typically gain the weight back since they do not change their eating habits. As for bodybuilders they do intermittent fasting but not to loose fat but to gain muscles. For some people this works as long as they eat sufficient calories.
- lm28469 4y ago
  > The study only included recommendations to the timing of food intake and did not provide recommendations for calorie and macronutrient intake or physical activity. > 116 overweight and obese participants Yeah I mean IF isn't magic. If you sit in front of netflix and eat three 800cal bags of chips it doesn't matter much if you're doing IF or not. I'm doing IF for years and go to the gym every other day, most of the time fasted. I made good progress, lost fat, gained muscles, and most importantly I feel amazing. Eating schedule is only a part of the equation. You still need to eat proper food and exercise.
Lio 4y ago
As I understand it, based on books such as Faster[1] by Michael Hutchinson, it depends on the intensity of what you do. At low intensity exercise you can just burn just fat. The body can only get so much energy from fat in a given time, so at higher intensity levels it will try to get energy from both fat and stored carbohydrates. Once you run out of easily available carbs it will try to supplement energy from the next available store, which is protein. i.e. muscle. So this will happen well before you run out of body fat. You can apparently increase the amount of base energy you can get from fat by training cell mitochondria with lots of low internet exercise. Eg lots and lots of zone 1 or 2 on the Coggan zone system. 1. http://www.michaelhutchinson.co.uk/faster.html http://www.michaelhutchinson.co.uk/faster.html
- TimSchumann 4y ago
  This is actually my understanding of it as well, though I kind of arrived at the conclusion on my own pulling from various sources and experience. People think about fat as if they have access to it all, but it's a surface area per unit time problem. Like all the chemistry in life, on some level, it's diffusion limited. What you should be thinking about while fasting is not letting your basal rate/time + exercise expenditure/time exceed your total energy available/time. I got pretty good at estimating this, but I wish there were an easy way to measure it. Everything is stream processing, not discrete units.
  - beagle3 4y ago
    The missing part in your description, to the best of my understanding, is fat to ketone conversion - you don’t use the fat directly, the process takes time, so ketones have to already be circulating when you need them. It can also explain why ketogenic diets work for many people - if you exercise every few days, your body will maintain sufficient blood ketone level for your exercise days, but unlike glucose, ketones that are not used get peed out eventually (and not stored/converted back to fat). Couldn’t find anyone knowledgeable enough to confirm I am right, but also no one to tell me I’m obviously wrong - still looking for one of those answers.
    - 4y ago

alecco 4y ago

That's controlled by total calories. Fasting improves body composition for diets with the same macros.

no1lives4ever 4y ago

I did a 7 day fast, and I mostly ended up losing fat. While I did not do any scientific measurement, i was able to exercise the same post the 7 day fast and my belly fat came down big time. Maybe body builders lose lean body mass when they fast, but it does not seem to hold true for the average human.

sdze 4y ago
You have mostly lost water to be precise. As well as muscle. You need an expensive Dual-energy X-ray absorptiometry scan in order to precisely tell the body mass composition.
- aenis 4y ago
  How would you know, without the "expensive" densitometry scan? My anecdotal experience: I lost weight via alternate day fasting and did indeed shell out the 120 euro that two scans cost me. I lost mainly fat, my lean body mass after 6 months was down 4 pct, within error range I'd assume. I worked out normally through the entire period and even did things like a 200km bike trip during a 72hr fast. (I did a few of those to compensate for not fasting on holidays). Great experience, never felt better tbh. One thing I think I learned was the exact threshold of power that allowed me to keep burning fat. Its hard to describe the feeling but after doing this for months (over a year by now) I think I know exactly when I can still push and continue on fat, and when I need to slow down to prevent lbm loss. Doing sprints, short intervals etc. would likely cause me to break proteins in the body and indeed be counterproductive - but here more research is probably needed, and individuals will likely have different thresholds.
- hsn915 4y ago
  Why would the body shed water instead of tapping into stored fat when there's no external energy coming it? This is delusional.
- orangepurple 4y ago
  If you can't get a DEXA scan there is an equation published in December of 2021 which approximates it well: The new equation [%BFNew = 6.083 + (0.143 × SSnew) - (12.058 × sex) - (0.150 × age) - (0.233 × body mass index) + (0.256 × waist) + (0.162 × sex × age)] explained a significant proportion of variance in %BF5C (R2 = 0.775, SEE = 4.0%). Predictors included sum of skinfolds (SSnew, midaxillary, triceps, and thigh) and waist circumference. The new equation cross-validated well against %BF5C when compared with other existing equations, producing a large intraclass correlation coefficient (0.90), small mean bias and limits of agreement (0.4% ± 8.6%), and small measures of error (SEE = 2.5%). Generalized Equations for Predicting Percent Body Fat from Anthropometric Measures Using a Criterion Five-Compartment Model Zackary S Cicone, Brett S Nickerson 1, Youn-Jeng Choi 2, Clifton J Holmes 3, Bjoern Hornikel 4, Michael V Fedewa 4, Michael R Esco 4 Affiliations expand PMID: 34310492 PMCID: PMC8785250 (available on 2022-12-01) DOI: 10.1249/MSS.0000000000002754 https://pubmed.ncbi.nlm.nih.gov/34310492/ https://pubmed.ncbi.nlm.nih.gov/34310492/

ycombinete 4y ago

More like visceral fat

orangepurple 4y ago

Completely incorrect. Time-restricted eating and concurrent exercise training reduces fat mass and increases lean mass in overweight and obese adults https://pubmed.ncbi.nlm.nih.gov/34042299/ https://pubmed.ncbi.nlm.nih.gov/34042299/

TimSchumann 4y ago
Agree. I notice zero lean body mass loss while fasting. At least no more than I would just sitting on the couch doing nothing.