One Pound of Fat - How many calories in 1 lb of fat?
Need to lose one pound of fat? Want to see what it looks like?...
Unless you've had the privilege of attending the dissection of an unembalmed human cadaver-- then chances are you might have never seen what body fat looks like just as it appears in the living body.
Your next best option then, is to take a close look at a realistic body fat 'replica'.
These replicas are specially designed to closely resemble in true colour what body fat looks like in the human body.
Of course, if you can't hold one of these models in your hands either, then your next best bet after that is to examine a photograph… much like the one provided here.
One Pound of Fat Represents 3500 Calories...
So, if this is what one pound of fat looks like in the body, how many calories does it take to burn that splash of fat?
Almost every fitness organization and health agency repeats the message that one pound of fat represents 3500 calories. This means to lose one pound of fat, you either have to:
1. Eat 3500 calories less,
2. Burn 3500 calories more through physical activity,
3. Or some combination of both by eating less and moving more for a combined total of 3500 calories.
First, let's get some quick math out of the way...
In America we weigh ourselves in pounds. In Europe we may weigh ourselves in kilograms. To convert pounds to kilograms we divide by 2.2 because there are approximately 2.2 pounds in one kilogram.
So a 150 lb person would weigh about 68.18 kilos.
The beauty of the decimal metric system is that all units are related by powers of ten. For instance, 1 kilogram is equal to 1000 grams.
So saying 1 kilogram is equal to 2.2 pounds is the same as saying 1000 grams is equal to 2.2 pounds.
Therefore, 1 pound is equivalent to 454 grams, i.e., 1000 g / 2.2 lbs = 454.54 g/lb.
But here's an interesting question...
If one pound is the equivalent of 454 grams, and one gram of fat contains 9 calories--
Then why is one pound of fat not equal to 4086 calories?
--454 g x 9 kcal/g = 4086 kcal
What happens to the missing 586 calories (i.e., 4086 - 3500 = 586 kcal)?
The Case Of The Missing 586 Calories!
Many people know that 1 pound of fat represents about 3500 kcal, but not many people know why or how that number is derived.
It turns out in the body, your fat cells are not 100 percent fat.
Adipose tissue contains about 5 to 10 percent water. Of course, water has zero calories. Another 3 to 5 percent is not absorbed from the digestive tract and ends up as excrement.
Therefore, a fat cell only contains approximately 87 percent fat:
454 g x 9 kcal/g x 0.87 = 3554.82 kcal
For the sake of simplicity, we round it off to 3500 kcal.
So, if we wanted to lose one pound of fat weekly, we would have to find ways of creating a caloric deficit equal to 3500 calories or 500 calories per day (i.e., 3500 kcal / 7 days = 500 kcal/day).
This means reducing our caloric intake by 500 calories, increasing our energy expenditure through physical activity by 500 calories, or by combining both, such as eating 250 calories less and burning 250 calories by moving more every day.
For optimal results, it's often recommended to combine both nutrition and physical activity to achieve your body fat loss goals.
But to give you an idea of how much exercise alone, you would need to perform to burn a pound of fat, let's use walking as an example and the very, very, rough estimate of about 100 calories expended per mile.
If you walked an extra 3.5 miles three days a week, it would take you about three and a third weeks-- or 10 walk days to melt off that splash of fat.
Of course, bear in mind that any activity requiring greater force production performed at higher intensities will always result in greater energy expenditure and thus, faster weight loss.
...Just be sure your physical activity level is commensurate with your own physical abilities, fitness experience, age, and exercise goals.
