“RMR can be estimated simply by multiplying body weight by 10-11 calories/pound (22-24 cal/kg).”

“… the amount of LBM appears to predict roughly 65% of the variance in RMR is attributed to differences in lean body mass.”

“I want to be clear that here I’m using lean body mass generally to include muscle. organs, brain, etc. ”

“Despite making up nearly 40% of your total body mass, muscles only contribute about 25% of your total RMR. In contrast, your organs account for nearly 60% of your total RMR because they are so much more active.

“… fat does use a small amount of calories and also contributes to RMR… maybe 3 calories per pound… ”

“at rest, a pound of muscle burns about 6 calories. ”

“A 10 lb muscle weight gain may only raise BMR by 60 calories or so.”

“Ignoring the adaptive component of metabolic rate (see next section), a 10 lb weight loss would only reduce metabolic rate by about 100 calories per day.”

So… my question is, if a person lost 10 lbs, why would you assume a reduction in metabolic rate of 100 calories? I get that you’re just multiplying 10 * the 10 lbs bodyweight lost.

However, you stated (skeletal, cardiac?) muscle makes up only about 40% of bodyweight, and 25% of RMR. Water/blood, bone, brain tissue, and smooth muscle/organs make up the other 60% (bodyweight), and also 60% of RMR, right? So why are you assuming that they too will be significantly reduced – by proportion – in weight & activity?

If 100% of that lost were skeletal muscle, would that not amount to just a 60 calorie reduction in RMR?
If 100% were fat, would that not amount to a 30 calorie reduction?
If 50% were fat and 50% were muscle, would that not amount to a 45 calorie reduction?

I admit I don’t know, but I would think that if a person is losing weight (hopefully) mostly in the form of fat, some carbs, and a small amount (above normal expenditure anyway) of protein – even in the amount of 10 lbs total bodyweight lost – the relative amount of active organ tissue reduction would be quite small or negligible.

Am I wrong in that assumption? I realize that in a much larger amount of bodyweight lost – say, 50-100 lbs – some of that would certainly be things like connective & organ tissue (since perhaps they’re able to work more efficiently due to less strain or demand on them), but is that still the case in smaller amounts of weight?

Thanks,

Rob

Awesome site, by the way.

You plan refeeds at a sufficient frequency to help offset the metabolic slowdown and hunger issues. So they only end up being on low calories for a short-period of time before an influx of calories.

Or use drugs.

Or both.

Lyle