Using body fat to find ideal weight

nmgu
nmgu Posts: 31 Member
edited November 16 in Getting Started
I was just curious if this was possible.

I'm 5'8". A few years ago I dropped to 155lbs. It was scary. My ribs stuck out, my hips were sharp angles. I was underweight. But my BMI was healthy. Now I'm at 227 with 36% body fat.

I did some quick calcs and found if I'm aiming for a body fat of 20% I should aim for a weight of 181. This assumes a stable amount of lean body mass. Can I trust this?

Replies

  • __TMac__
    __TMac__ Posts: 1,669 Member
    edited February 2017
    Maybe. How did you measure your current BF%?
  • TR0berts
    TR0berts Posts: 7,739 Member
    Generally speaking, yes. Just understand that it's likely that - while losing weight - you probably won't just lose fat. As such, when you get to 181, you might not be 20%, but slightly higher (like 22-23%). But it's a pretty good way to set an initial goal.
  • nmgu
    nmgu Posts: 31 Member
    edited February 2017
    Widest point on hips, around my navel, narrowest point on waist, wrist, widest part of forearm, widest part of bicep, widest part of thigh, and neck. Then put in height and weight.
  • cwolfman13
    cwolfman13 Posts: 41,865 Member
    nmgu wrote: »
    I was just curious if this was possible.

    I'm 5'8". A few years ago I dropped to 155lbs. It was scary. My ribs stuck out, my hips were sharp angles. I was underweight. But my BMI was healthy. Now I'm at 227 with 36% body fat.

    I did some quick calcs and found if I'm aiming for a body fat of 20% I should aim for a weight of 181. This assumes a stable amount of lean body mass. Can I trust this?

    Who knows...just start and let the details sort themselves out...don't worry about some specific number as your goal.

    I started at 220...I'm 180ish in the picture <<<...about 12-15% BF...I thought I was going to have to cut a lot more weight to be 12-15%
  • nmgu
    nmgu Posts: 31 Member
    TR0berts wrote: »
    Generally speaking, yes. Just understand that it's likely that - while losing weight - you probably won't just lose fat. As such, when you get to 181, you might not be 20%, but slightly higher (like 22-23%). But it's a pretty good way to set an initial goal.

    Thanks.

    Went back. Assuming a 7% reduction in lean body mass and a goal body fat of 20% (both are aggressive numbers) adjusted goal is ABOUT 169 ignoring significant figures.

    Yay math!
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