wondering how or who came up with 3,500 cals in a pound of fat?

[Speizach]

The weight loss standard of today is 3500 calories to lose a lb of fat. that can be either through subtracting 500 cals/day from your diet or increasing your output 500 cals/day through exercise, or a combination of the two, which would equate to 7 x 500 = 3,500 calories deficit for a weak, supposedly equaling a pound of fat.

what I was wondering is this, 1 pound = 453.6g. And a gram of fat is 9 calories. So wouldn't that mean you need to burn 9 calories x 453.6g ? which if you round up to 454 about 4086, if you don't its 3920. take the about average, which is 4,000. Wouldn't that mean that to lose a pound of fat off one's body they need to have a calorie deficit of around 4,000 calories, not 3,500? I'm just wondering if there is some kind of caloric exchange I don't know about, or if there is another reason the magic number is 3,500?

[cldillmann1]

The weight loss standard of today is 3500 calories to lose a lb of fat. that can be either through subtracting 500 cals/day from your diet or increasing your output 500 cals/day through exercise, or a combination of the two, which would equate to 7 x 500 = 3,500 calories deficit for a weak, supposedly equaling a pound of fat.

what I was wondering is this, 1 pound = 453.6g. And a gram of fat is 9 calories. So wouldn't that mean you need to burn 9 calories x 453.6g ? which if you round up to 454 about 4086, if you don't its 3920. take the about average, which is 4,000. Wouldn't that mean that to lose a pound of fat off one's body they need to have a calorie deficit of around 4,000 calories, not 3,500? I'm just wondering if there is some kind of caloric exchange I don't know about, or if there is another reason the magic number is 3,500?

1) One pound equals 454 grams (decimal places aside, this is a fact);

2) Fat has nine calories per gram (this is the universally accepted conversion, but it is an estimate and significantly rounded down from even the original estimate);

3) Human fat tissue is approximately 87% lipid (this is a widely accepted conversion, but it is also an estimate).

Putting these together, we can derive the sum that 454 grams of body fat tissue has approximately the calorific energy of 395 grams of pure fat (454 grams x 87%), that is 3,555 calories (395 grams x 9).



source: google is the beast

[Spencer43783]

Really good question OP, need more people like you on this forum! Learn something new every day. Some more fat info if you're interested:

http://en.wikipedia.org/wiki/Adipose_tissue

[necon76]

It was decreed by Jesus.

[cldillmann1]

It was decreed by Jesus.

my gardener?

....brb going back to nmisc

[PR1MO]

I came up with it OP. Got a problem?

[Spencer43783]

my gardener?

....brb going back to nmisc

Post something informative, then make me laugh.

You sir, need to spread some Reputation around before you give any more to cldillmann1.

[Bonkies]

WAT in humans is composed primarily (anywhere from 80 to 95%) of lipid. By lipid, I
mean stored triglycerides (TG) which are simply a glycerol molecule bound to three free
fatty acid (FFA) chains. The remaining part of the fat cell is comprised of a little bit of
water as well as all of the cellular machinery needed to produce the various enzymes,
proteins, and products that fat cells need to do their duty. As it’s turning out, fat cells
produce quite a bit of stuff, some good, some bad, that affects your overall metabolism.

For the record, one pound of fat is 454 grams and let’s assume 90% lipid on average. So
about 400 or so grams are actual stored TG. When burned by the body, one gram of fat
provides 9 calories so 400 grams of fat contains about 3600 calories of stored energy. Now
you know where the old axiom of ~3,500 calories to lose a pound of fat comes from.

^^^

WAT = white adipose tissue, the primary type of fat in the human body.