Body fat percentage VERSUS Body Mass Index (BMI) for evaluating progress?

DvoycY
DvoycY Posts: 38 Member
edited November 29 in Health and Weight Loss
If my goal is to be lean and healthy, which one of the two is better? First, I went by BF but it appeared that to achieve a lean physique I would then be considered underweight by BMI; therefore, I went with BMI, attempting to stay about 19. Would you say it is sustainable to be considered underweight by BMI to have a lower body fat percentage? For reference, BMI is about 19 now and BF is 9%. IIRC, circa 8% is somewhat sustainable. However, it does seem to work out, as if I go below 8% BF my BMI will be considered too low, but I am still interested in your opinions and experiences which one is better to evaluate progress? Visual wise, I look good but there is always place to improve, so I go by numbers for further benefit.

Replies

  • countcurt
    countcurt Posts: 593 Member
    DvoycY wrote: »
    If my goal is to be lean and healthy, which one of the two is better?

    Better for what? I don't mean to be flippant, but on the surface, the answer here is obviously healthy. In the short term, however, many people don't prioritize long term goals.

    At 9% BF you are pretty lean. Which begs the question of how lean you want to be. You can also be very lean by adding some additional muscle. Which would also keep your BMI in the healthy range.


    It's true the BMI is an imperfect tool. It is, however, a pretty good tool for the vast majority of people. And, it's much easier to accurately track on a day to day basis.

  • jjpptt2
    jjpptt2 Posts: 5,650 Member
    Both can be fine measures. Both can be poor measures. It's up to you and how you use them.

    If you're trying to hit a number because it's what an industry or society or whatever else says is "normal" or "sustainable" or "acceptable" or whatever else, then you're probably going to run into problems.

    If you use it simply as a metric for gauging progress/change, then both are probably fine options for you. You know yourself and your body... you know what you want to look like, where you feel good, and what you can or can't sustain (and if you don't, you'll learn it pretty quickly). So use the number as a reference point, not as a comparison tool. If you want to be leaner, then work to get the number lower regardless of how that number compares to standards or normal or whatever else.
  • DvoycY
    DvoycY Posts: 38 Member
    Thanks, everyone. I agree that it is still necessary to be wary of any tool being used, appreciated! Don't have any recent pictures, as I am bloated after a cheat-day today but this is me a couple of days after the cheat-day last week: https://imgur.com/a/rCPlHxq I have to agree, 10% seems more closer than below. Cheers
  • jseams1234
    jseams1234 Posts: 1,219 Member
    DvoycY wrote: »
    Thanks, everyone. I agree that it is still necessary to be wary of any tool being used, appreciated! Don't have any recent pictures, as I am bloated after a cheat-day today but this is me a couple of days after the cheat-day last week: https://imgur.com/a/rCPlHxq I have to agree, 10% seems more closer than below. Cheers

    Ok, that's a much better picture. I'd agree that you are pretty close to 10%... I still don't think you look drastically "underweight". A bit slimmer than is my personal preference but you look fit, strong, and healthy.
  • MikePTY
    MikePTY Posts: 3,814 Member
    I think in this case both are trying to tell you the same thing, which is that having a body percentage of under 10% is probably underweight, especially if it gives you a low weight. Keeping it a little bit higher and trying to add some muscle would be a good thing.
  • Tic78
    Tic78 Posts: 232 Member
    Your in an ideal place to slow bulk and put some muscle on. You can still have as low bf at a higher weight. That’s assuming you want a little more size
  • CarvedTones
    CarvedTones Posts: 2,340 Member
    Except for very short, petite people, a BMI below 20 isn't generally considered healthy.

    Here is something I found on healthy body fat % for the general population (not elite athletes):
    Body Fat for Adult Males
    A healthy body fat percentage for an 18-year-old male falls between 10 and 19 percent, while a 19-year-old male should be between 9 and 19 percent. Men 20 to 39 years are in the healthy range at 8 to 19 percent. Adult males 40 to 59 years should strive for 11 to 21 percent body fat and those 60 and over want to have between 13 and 24 percent body fat.
  • ahoy_m8
    ahoy_m8 Posts: 3,053 Member
    It goes back to the question what "progress" are you trying to evaluate. If 10%BF is accurate, that is already quite lean. Is your goal to gain LBM? Or lose fat? Or maintain where you are?

    For evaluating progress, BMI is essentially equivalent to your body weight scale, and it is probably pretty accurate. If your goal is maintaining with no significant body composition changes, this is the simplest route.

    For evaluating progress, BF% is more difficult due to measurement error. DEXA scans can be +/-3%, and that is not accurate enough to track progress. It seems like people who are serious about measuring their bulk rely on frequent tape measure measurements, but skill is involved. If your goal is to change your body composition, you could get good advice on the Weight Gain/Bulk board.

  • countcurt
    countcurt Posts: 593 Member
    Well, you are indeed lean. And thin. If you like the way you look and can sustain at this level, go for it. You may wish to consider how sustainable it is and go from there.
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