The 1 percent rule - how much fat can we really metabolize per day/week?

Options
NovusDies
NovusDies Posts: 8,940 Member
edited July 2018 in Health and Weight Loss
Instead of bumping:

https://community.myfitnesspal.com/en/discussion/110668/how-much-fat-can-we-really-metabolize-per-week

I wanted to open the discussion up again since it is 8 years later and not all the links referenced still work. I assume there is new information that might help but it is hard to google it because there are so many quick losing schemes that junk up the search.

I am mostly curious about when it is safe to use the 1 percent rule, what that means, and when it is time to return to the standard recommendation of 2lbs per week?

This does apply to me directly because I am tired of second-guessing myself on my loss rate. I am planning on a doctor visit next week now that it has been 6 months but I want to be able to balance anything he says with my own research (or in this case your research).

This reply from the original thread caught my eye: (Please Click 'Show Previous Quotes' for the Science Portion)
cmw72 wrote: »
It turns out there a maximum value that the body can metabolize from fat per day.

This article by Lyle McDonald explains it pretty well:
http://www.mindandmuscle.net/articles/lyle_mcdonald/maximum_fatloss

From the article:
Based on a somewhat simplified analysis of what data exists (including the seminal Minnesota semi-starvation experiment), they conclude that the maximal rate at which fat stores can provide energy to the body is 290 +- 25 kj/kg which is approximately 31 kcal/lb of fat per day.
Say we have a 180 lb male at 15% bodyfat. He has 27 lbs. of fat, and his maintenance calorie intake is 15 cal/lb or 2700 calories. With 27 lbs. of fat, he should be able to sustain a caloric deficit, from diet alone, of 27 lbs. fat * 31 cal/lb = 837 calories/day. So he could reduce his calories to 1863 (ha! 10 cal/lb) and shouldn’t lose any LBM at that level of intake. He should get a weekly fat loss of just over 1.5 lbs./week.

So, it's quite possible for a seriously obese individual to lose a significant amount of fat per week. For somebody who has significantly less body fat, it would be much more difficult, if not impossible (mathematically).

«1

Replies

  • TavistockToad
    TavistockToad Posts: 35,719 Member
    Options
    i have nothing useful to add, but am tagging to follow
  • jemhh
    jemhh Posts: 14,261 Member
    edited July 2018
    Options
    Can't really speak much on the 1% part but as for the 31 cal/lb of fat, Lyle McDonald has said that he does not feel that it is relevant to dieting in an optimal manner. I can't give you direct links but he has a Facebook page on which he has repeated this several times. I would completely ignore the 31 cal thing.
  • try2again
    try2again Posts: 3,562 Member
    Options
    I started a similar thread last year. Not much else available then:

    https://community.myfitnesspal.com/en/discussion/10507624/limit-to-the-amount-of-fat-that-can-be-burned-in-a-day#latest
  • NovusDies
    NovusDies Posts: 8,940 Member
    Options
    jemhh wrote: »
    Can't really speak much on the 1% part but as for the 31 cal/lb of fat, Lyle McDonald has said that he does not feel that it is relevant to dieting in an optimal manner. I can't give you direct links but he has a Facebook page on which he has repeated this several times. I would completely ignore the 31 cal thing.

    I was wondering about that since it contradicts some of the current wisdom of slowing to 1lb and then .5lb per week as you get closer to your goal weight.
  • NovusDies
    NovusDies Posts: 8,940 Member
    Options
    try2again wrote: »
    I started a similar thread last year. Not much else available then:

    https://community.myfitnesspal.com/en/discussion/10507624/limit-to-the-amount-of-fat-that-can-be-burned-in-a-day#latest

    Thanks for the link. Your thread didn't come up in the google search and the search here is not worth much.

  • jasondjulian
    jasondjulian Posts: 182 Member
    Options
    try2again wrote: »
    NovusDies wrote: »

    I am mostly curious about when it is safe to use the 1 percent rule, what that means, and when it is time to return to the standard recommendation of 2lbs per week?

    I think the "standard recommendation" of 2 lbs/week is just a different expression of the 1% rule, assuming the majority of people will fall in a range where 2 lbs/week would be the high end of 1%.

    Agreed... probably also because we think of 2lb/wk as roughly 7000 calories per week deficit, whether that's accurate or seems debateable, but let's assume it's close enough.. I think to shoot for any more than 2 ACTUAL pounds per week would require even higher calorie deficits and that is just realistically too difficult for most people.

    I don't even know how I would make a 10-11,000 calorie per week deficit work for me, assuming I still had all of my weight to lose (I don't, I'm at or near target weight, just need to recomp some fat:muscle).
  • try2again
    try2again Posts: 3,562 Member
    Options
    jasondjulian wrote: »
    try2again wrote: »
    NovusDies wrote: »

    I am mostly curious about when it is safe to use the 1 percent rule, what that means, and when it is time to return to the standard recommendation of 2lbs per week?

    I think the "standard recommendation" of 2 lbs/week is just a different expression of the 1% rule, assuming the majority of people will fall in a range where 2 lbs/week would be the high end of 1%.

    Agreed... probably also because we think of 2lb/wk as roughly 7000 calories per week deficit, whether that's accurate or seems debateable, but let's assume it's close enough.. I think to shoot for any more than 2 ACTUAL pounds per week would require even higher calorie deficits and that is just realistically too difficult for most people.

    I don't even know how I would make a 10-11,000 calorie per week deficit work for me, assuming I still had all of my weight to lose (I don't, I'm at or near target weight, just need to recomp some fat:muscle).

    Yes, according to the rule, I could still "safely" lose 2 lbs/week, but it would give me a calorie allowance of close to 1000. Not happening.
  • kimny72
    kimny72 Posts: 16,013 Member
    Options
    In to see where this goes as well! I've seen articles on Mayo Clinic, the NHS, and other places I consider trustworthy that state the 1% at most guideline, but nothing to ever suggest where it comes from. I'm wondering if it just comes from an understanding that if you're in the 100's, you probably can't sustain more than a 500 cal deficit consistently, if you're in the 200's you can't sustain more than a 1,000 cal deficit consistently, etc based on averaged calorie needs.
  • try2again
    try2again Posts: 3,562 Member
    Options
    jemhh wrote: »
    NovusDies wrote: »
    jemhh wrote: »
    Can't really speak much on the 1% part but as for the 31 cal/lb of fat, Lyle McDonald has said that he does not feel that it is relevant to dieting in an optimal manner. I can't give you direct links but he has a Facebook page on which he has repeated this several times. I would completely ignore the 31 cal thing.

    I was wondering about that since it contradicts some of the current wisdom of slowing to 1lb and then .5lb per week as you get closer to your goal weight.

    Well, and the other part of the conversation is that even if 31 cals/lb of fat was accurate, even if 1% of bodyweight per week loss is accurate as far as being "safe", it doesn't mean that either one is necessarily optimal. What is optimal for a person is what is sustainable. For some people that could be 1% of bodyweight per week. For others it might be a half pound per week. People seem to look at 1% of bodyweight and 1-2 lbs per week as what they "should" lose when those are really just guidelines to what is considered to be a safe rate of loss.

    I was racking my brain trying to come up with that word! (optimal) Thank you! :)
  • steveko89
    steveko89 Posts: 2,217 Member
    Options
    Cmriverside's post got me thinking about my own experience and how I've gone about doing things since I started here back in 2012. For context, I'm male, currently 29yo, and stand 6'1".

    All in all, on day one of MFP I was only a few pounds heavier on the scale than I am now (178 vs. 173), however I was not in nearly the sort of shape I am now having really gotten into lifting since mid-2015. Not being as knowledgeable, like many I set my loss rate for 2 lbs/week which give me 1200 or just a little over and I was able to deal with that pretty well. However, at that time I wasn't using a food scale or logging exhaustively on weekends and didn't necessarily lose to match 2lb/week but dropped from 178 down to a low of 159 just before getting married in June of 2013. I estimate that period of weight loss occurred with a lean body mass of around 140 lbs, equating to going from ~20% body fat to ~12% but with not too much muscle mass to write home about. I had my goals set to a limit of 1240 calories for the longest time, convinced that I'd be happy with my body if I just kept losing weight. My adherence and logging consistency was lackluster and I floated around in the 160s until late 2014/early 2015.

    I'd gained fat back up to as high as 175. I knew how I could get back down into the low 160s but knew that I wasn't appreciably happy with how my body looked at that lower weight compared to how I looked then; I finally realized I needed to add some muscle to look the way I desired. I started lifting with adjustable dumbbells and a cheap bench in spring of 2015, but it wasn't until 8/3/15 (A Monday, surprise surprise), that I finally upped my calorie target to a more reasonable number of 2240 (+exercise). Being a few years ago I'm unsure of the origin of that target; probably in the ethos of "eat big, lift big" or something along those lines. Being overweight through adolescence and spending the last three years thinking about 1250 calories, 2240 seemed like a mountain of food. To make an excessively long story at least a little shorter, I've probably added at least 10 lbs of muscle since that point and sit a 173 lbs with decent-but-could-be-better definition. Presently, my target is set for 1800 calories but I generally shoot for just being in the window between that point and my TDEE (~2500) and typically average a little over 2100 when I'm on the ball as far as caloric compliance is concerned. Years removed from trying to hit 1250 (at least during the week), I don't remember, and can't imagine how I felt trying to eat that little at what I'd describe as similar levels of leanness.
  • middlehaitch
    middlehaitch Posts: 8,484 Member
    Options
    Ooh, thank you for starting this discussion. I was looking for this thread (below) the other day when someone was asking about a reasonable calorie deficit.
    https://www.ncbi.nlm.nih.gov/m/pubmed/15615615/

    Where I think the 30cal of fat per lbs body weight is useful is when you have a lean person trying to get leaner, fast, or an obese person wanting to eat at the very minimum calorie intake and holding on by the skin of their teeth.

    Pointing out that there is a limit to how much fat can be burnt before a more than acceptable amount of LBM starts to be burnt can give one more food for thought.

    Whether the equation is 100% accurate it is hard to know but, just like the 1or 2 percent rule, it is a good guideline.

    I do think @jemhh's post is spot on.
    Cheers, h.

  • pinuplove
    pinuplove Posts: 12,874 Member
    edited July 2018
    Options
    lorrpb wrote: »
    2 lbs/week is good if you have 75 lbs or more to lose
    50-75 lbs is 1.5 per week
    20-50 is 1 lb per week
    under 20 lbs to lose is .5 per week
    This makes a lot more sense to me than 1% of bodyweight. It's probably safe to say that no one under 175 should be aiming for 1% loss per week.

    This makes more sense to me as well. Maybe the 1% guideline works better at higher weights or those who have a bit more to lose.

    To lose 1% of my body weight per week I'd need a 700-calorie daily deficit off a maintenance amount of 1700. If I were more active I could achieve it by not eating all my activity calories back, but I'd still be netting under 1200 and hangry all the time, and that's just not pretty.
  • NovusDies
    NovusDies Posts: 8,940 Member
    Options
    lorrpb wrote: »
    2 lbs/week is good if you have 75 lbs or more to lose
    50-75 lbs is 1.5 per week
    20-50 is 1 lb per week
    under 20 lbs to lose is .5 per week
    This makes a lot more sense to me than 1% of bodyweight. It's probably safe to say that no one under 175 should be aiming for 1% loss per week.

    That works just fine if you are in the vicinity of 75lbs or under. The problem is what happens when your "or more" is substantially more? It seems like there should be a logical place where the 1 percent rule kicks above a certain weight.

    I personally don't use the rule. I think it is too aggressive regardless of my situation. I have been taking the 1 percent and substracting 1 from it. That might change to .5 at some point depending on how I feel when more of this weight is gone.



  • lorrpb
    lorrpb Posts: 11,464 Member
    Options
    NovusDies wrote: »
    lorrpb wrote: »
    2 lbs/week is good if you have 75 lbs or more to lose
    50-75 lbs is 1.5 per week
    20-50 is 1 lb per week
    under 20 lbs to lose is .5 per week
    This makes a lot more sense to me than 1% of bodyweight. It's probably safe to say that no one under 175 should be aiming for 1% loss per week.

    That works just fine if you are in the vicinity of 75lbs or under. The problem is what happens when your "or more" is substantially more? It seems like there should be a logical place where the 1 percent rule kicks above a certain weight.

    I personally don't use the rule. I think it is too aggressive regardless of my situation. I have been taking the 1 percent and substracting 1 from it. That might change to .5 at some point depending on how I feel when more of this weight is gone.



    Right, more than 75 to lose would be 2 lbs or up to 1%. Wish you the best in your journey.

Categories