If you want to lose weight, then you’ll need to create a caloric deficit. In other words, you have to burn more calories than you consume. The size of this deficit will determine how quickly you lost weight.
Generally, when people talk about losing weight, they’re talking about losing fat. So just how many calories are there in a pound of fat?
Calories in fat, protein, and carbohydrates
From a dietary perspective, there are 4 calories in a gram of protein and 4 calories in a gram of carbohydrates. In contrast, there are 9 calories in a gram of fat. Given that there are 454 grams in a pound, this means that there are 9 x 454 = 4086 calories in a pound of fat. Right? Well, not really…
Calories in a pound of body fat
As it turns out, body fat (also known as adipose tissue) contains more than just fat. It also contains protein, connective tissue, water, etc. Thus, a pound of body fat corresponds to “just” 3500 calories.
This is a bit of an oversimplification, but… If you consume 3500 more calories than you burn, you’ll gain a pound of body fat (more or less). Conversely, if you burn 3500 calories more than you take in, you’ll lose a pound of body fat.
So… If you’re looking to lose a pound per week, you’ll have to create a caloric deficit of 500 calories per day. This isn’t an easy thing to do unless you’re making smart choices in the kitchen. Yes, you can amp up your exercise regimen, but it take a lot of exercise to burn off junk food.
Get free updates via e-mail!
{ 5 comments… read them below or add one }
Hmm…the problem is that you don’t just lose fat when you lose weight. You drop water and muscle too so technically to lose a pound of fat you probably need to lose quite a bit more on the scale.
I’m still relatively new at the technicalities of intake/output.
@Andrew, are you losing the muscle or are you recreating or tightening the muscle that was already there?
nice post.
Is it also true (or along lines) that if you have calorie intake of more than 3500 that you’ll gain one pound?
Victore: More or less, though weight gain and weight loss is a complex issue.
@Victor — If you consume 3500 calories more than the calories exerted — it is theory that you may gain a pound. It makes sense — if you eat a lot more than you use…expect a gain.