How to use the LBM calculator

#1

As I’ve mentioned I am severely underweight. I am small, the ideal weight for somebody of my frame and height is about 110 lbs.
I want to figure out a good amount of protein, so if I need at least 1g protein per LBM and I go to a site like https://www.calculator.net/lean-body-mass-calculator.html
should I be putting in my current weight which is far below what it should be, or my ideal healthy weight?

(You've tried everything else; why not try bacon?) #2

The choice is yours. Do what works best for you.

Dr. Phinney, in his books and at Virta Health, sidesteps the issue by referring to “reference weight.” The Virta Health site has a set of tables giving heights and target weights, with recommended protein intakes to go with them.

#3

No, you need 1g/lb of bodyweight. That going by LBM only exists here. You can’t calculate LBM, that’s make believe. You either measure it, or you’re making it up. Given that you’re underweight, if 110 is where you want to be, go for 110g as an absolute minimum protein intake. Track your intake and make sure you’re in a surplus at all times. Great time to start working out!

(You've tried everything else; why not try bacon?) #4

It is actually the recommendation of a number of experts, including Dr. Phinney. Though I must admit that Prof. Bikman recommends as high as 2.0 g/kg LBM. @richard has some thoughts on protein intake and ketogenesis, but hasn’t posted about it in rather a while. He is busy working on his doctorate right now, but perhaps he will have a moment in which to describe what the issues are.

All I know is the following: (1) Dr. Phinney has concerns about excessive protein intake limiting ketogenesis, but I don’t know the data on which he bases his concern. (2) Prof. Bikman is deeply concerned about muscle loss as we age, and he says there are data suggesting that our ability to assimilate amino acids declines as we age, so it is better to eat more when we are younger. Again, I am not familiar with these data. (3) @richard once calculated the protein intake at which ammonia toxicity becomes a concern, which was either 3.1 or 3.3 g/kg LBM, if memory serves. (4) Anything Ted Naiman says about protein intake should be taken with a shaker-full of salt, because he has a pronounced habit of enthusiastically reasoning far, far beyond the data.

#5

Yup, a lot of “experts” that don’t have any muscle on their bodies. I ignore anything that comes out of Phinney these days. I am a fan of Bikman, but don’t agree with everything either. People either love or hate Naiman, but unlike the others, although a smaller guy, he’s actually ripped up and has the power to get into the gym and move stuff, so he immediately gets more credit than the others. I’m still mixed on his P:E ratios, but people who can actually do things, automatically have more credit than those who say something else, and can’t, because the other one though it looked good on paper. Phinney can claim he proves his research all he wants, he works with bonebag runners, which if you’re a runner and want/need to look like that, that’s fine, I’d rather not look like I’m wasting away.

The 1g/lb of body weight became a standard for a reason, it works. On Ammonia toxicity, that’s completely dependent on the person, their muscle mass, and whether they can actually use the protein intake of if you’re going contributing to nitrogen wasting. At 3.1 3.3g/kg no way in hell I’d have that problem if going by LBM, been way over that before, and there’s no mistaking when you hit nitrogen wasting/toxicity, you literally smell like a litter box that hasn’t been cleaned in a week, as do your clothes from sweating it out.

#6

I wouldn’t use your actual weight. You actual LBM is way too low. I would use some number for your target LBM. Or even target full weight. A really fat one shouldn’t use the total weight, it’s okay but unnecessarily high for someone like me (maybe 40lbs extra) but your target body is still slim so the difference is small and some extra protein isn’t bad.

I would try to eat, like, 100g protein. Or a bit less if it’s so hard, your actual needs are probably lower. But as you need to gain and it’s usually not comfortable to eat super fatty with little protein, more protein sounds good to me.

#7

True. I consider guesstimations perfectly fine though. We don’t know our personal factors either. Some people even gain fat just fine eating 1g/kg protein for LBM, others need more than 2, normal people are in-between and 1.5-2 works for them. I personally like to be safe and go higher but I find it bad to force a probably unnecessarily high amount of protein. For some reason, some people need much effort and plan and whatnot for a more modest amount. They still shouldn’t go too low but using the highest numbers may be worse than doing, like, 1.5g/kg for guesstimated LBM. But goal weight is fine too as it’s usually close enough to LMB and eating a bit unnecessarily high protein is usually quite fine. At least if it’s not forceful.