3500 Cal/lb?

[PERKDOUG]

I have been trying to find the science behind the idea that 3500 calories is equal to a pound of fat loss in the human. This "fact" clutters every diet book and every nutrition book I read. But how did they come up with the figure 3500 calories equals a pound of fat? Did they do experiments or use some theoretical calculation to determine this figure? I Googled and all I found was "diet garbage".

Perhaps one you, through reading has come across the answer.

Thanks for your help!

[fgummett]

Fats contains a little more than double the number of calories per ounce as carbohydrates and proteins: 220 Calories per ounce (9.3 Calories per gram).

16 ounces (oz) = 1 pound (lb)

16 * 220 = 3,520 Calories in 1lb of Fat

But (without wanting to start a debate)... I no longer consciously count calories, so I don't really have any practical use for this number :)

--

The kilogram calorie, large calorie, food calorie, Calorie (capital C) or just calorie (lowercase c) is the amount of energy required to raise the temperature of one kilogram of water by one degree Celsius.

[PERKDOUG]

Frank my math is different from yours: (I think your gram to ounce conversion is in error) 1 oz = 28.35 gr


I do it this way:

1 lb (of fat) * 454 gr/ lb * 9 cal/ gr = 4086 cal (of fat)

4086 calories is very different from 3500 calories. That is why I raise the question.

[fgummett]

Well math never really was my strong suit... maybe that's why I never had much success with Calorie counting :cool:

Perhaps they make an allowance for Calories "lost" as heat?

I got the 220 Calories per ounce from here: "www.exo.net/~pauld/activities/food/countingcalories.html" (link gets lost for some reason)

Like I said it's just a meaningless number to me now anyway ;)

[Grunch]

I think the misconception comes from assuming that our body has a 100% efficiency. Just like a car we can't use all of the energy from a fuel because some of it is lost in the process. So 1 lb has more than 4000 kcal, but you just need to burn 3500 kcal through exercise to burn 1 lb of fat.

This link is interesting and explains why high fat doesn't work for exercise. Calories per pound of fat body fat contains 3500 calories per pound (http://www.weightlossforall.com/calories-per-pound.htm)