# Well this is a silly question about calories...

So - in a pound of body fat there are 3,500 calories, give or take.

Suppose that a person, all other things being equal, were to add the ingestion of 1 pound of beef tallow (about 3,600 calores) to their daily food intake, for ten days.

Would they:

Gain some other amount of weight substantially different from 10 pounds (like 5 pounds, or 20 pounds, but not 10.5 pounds)

Or gain nothing.

Were I not vegetarian, I would try it myself and post the results. Really.

By all other things being equal, I’m assuming that you are adding the calories to your regular diet and that you are not changing your proportion of active and sedentary behavior.

And let’s just make the beef tallow an equivalent amount of digestible food in smaller doses, because that much extra pure fat or extra anything may cause violent diarrhea that would mess up the equation.

You may see a slight increase in metabolic rate as your body copes with the extra food, but it’s unlikely that over as short a time as ten days you would completely reset your metabolism.

I’d guess that you would put on something close to but under 10 pounds.

I expressly chose the beef tallow for it’s vomitious nature.

I suppose the person could put some beef tallow on their cereal, or spread it on a bagle or something. Also, they could spread it out over the day.

Just like anything else, beef tallow isn’t 100% bioavailable, and it requires energy to digest, so it would be less than ten pounds.

It varies according to the individuals metabolism.

http://content.nejm.org/cgi/content/abstract/322/21/1477

84 days of eating 1000 calories above maintenance and the weight gain varied from 9.46 to 29.26 pounds. I read in the book The Fat of the Land that 1/3 of the weight gain in this study was muscle.

There are other studies on overfeeding. I read in another book dealing with the vermont prisoner overfeeding experiment http://www.unu.edu/unupress/food2/UID08E/uid08e05.htm
that the number of fat cells a person has determines how much weight they gain with overfeeding. Genetically obese people create new fat cells when they are overfed, while Genetically non-obese people keep the same fat cells which can only be expanded so much before they can’t hold anymore fat.

I don’t know if this has anything to do with the answer you wanted but figured i’d throw it in anyway since I know it.

How accurately were they able to measure maintenance calorie needs?

I don’t know how detailed the study was about that. However I have read other studies that said some people unconsciously responded to overfeeding by fidgiting alot and becoming more physically active, resulting in more calories getting burned. That was in the same book and I can’t remember the title right now.