How many grams of protein are in a pound of human muscle?
I don’t know. If you go to Fitday.com and put in different meats you’ll find a range between 82.6 grams protein per pound of chicken to 119.1 g protein per pound of turkey. Pork and beef fall in the middle of those two. For nutritional calculations if you figured 90 grams per pound of human muscle you’d probably be close enough. You could do Kjeldahl nitrogen to be really sure, but that’s a lot of trouble for a quick snack.
I’ll take a shot at it but will say at the outset that I am not even close to being knowledgeable about the subject. Rather, I think that using a few educated guesses and one or two articles I stumbled across, I may have an approximate answer to your question.
Note that I’m referring exclusively to human muscle in what I say below. Other animals may have different values.
Muscle contains glycogen but, in comparison to the much larger amount of protein and fat, the quantity is neglible. This is especially true after exercise when “all” the muscle glycogen has been used.
Muscle also contains some fat. Quantifying the precise amount seems to be a challenge and various methods have been used (CT, MRI, spectroscopy, . . . ) One study demonstrated that there was a range of about 50 to 70 mmol/kg muscle dry weight of intramyocellular lipid (IMCL)*. Since muscle is about 2/3 water (in men), that means there is approximately 17 to 23 mmol/kg wet muscle weight of IMCL. So, in one pound of wet muscle, there’d be about 7 to 10 mmol of ICML.
- whatever ICML really is
But, I have no idea what the molecular weight (MW) of ICML is. I doubt ICML is even homogeneous. Bottom line is that if we assume it’s entirely triglyceride, then we’d have 7 to 10 mmol of TG per pound of muscle. Since the MW of TG is about 860 g/mol, that translates to around 8 grams per pound of total muscle weight. OTOH, protein must make up the rest of the dry weight. Again assuming that muscle is 2/3 water and that one kg = 450 g, it means that there are about 150 - 8 = 142 grams of protein per pound of muscle.
BTW, note that some of the muscle protein is from connective tissue meaning that not all the protein in muscle resides in muscle fibres.
Bottom line answer: there are about 142 grams of protein in a pound of human muscle. Maybe.
Why are you measuring the protein in metric (grams) but the muscle in imperial (pounds). Wouldn’t it be a good start to adopt a consistent system of measurement? Or have I missed something?
The only reason I did was to be consistent with the OP’s question. Indeed, it was a pain.
One pound is 450g? Cause wouldn’t one kg be 1000g?
Yes. Though to be more precise, it’s closer to 454g in 1lb.
That’s how it’s done in the US. If you look at our nutritional labels, they all indicate grams per serving.
Yes, sorry, it was a typo - I meant to say that 1 lb is about 450 g
Well, human meat has been called “long pig” which seems to imply it tastes like pork. The official USDA Nutrient Data Laboratory is down (which is weird) but this site gives me 95 g of protein per pound for “Pork, fresh, loin, tenderloin, separable lean only, raw”. However, the table in the wikipedia article on meat give values of about 30 g per 4 oz or 120 g per pound.
These values are less than Dr. Gauss’ but I don’t see any meat that approaches 142 g per pound and the values in the food tables were determined through testing so I’d think they’d be more accurate. I’d guess most animal muscle is very similar in protein content but the actual protein content would depend on the fat content (or marbling) and what cut of meat you use.