# how much calories i need to burn to lost 1 lbs. of body fat?

by arabianights
Tags: body, burn, calories, lost
 P: 22 as title says
 P: 948 About 4000.
 P: 93 if you use energi and e= mgh and remember that the body is about 75% efficient. you can burn as much calories you want. just by lifting things over your head. which is about 2m.
Mentor
P: 24,989

## how much calories i need to burn to lost 1 lbs. of body fat?

One pound of fat is 3,500 calories. To lose a pound, in essense, you need to eat 3,500 calories less than you need.

In weight loss, other factors such as metabolism, water held in fat, etc... will affect how quickly and effectively you lose the weight.
P: 948
 Quote by Evo One pound of fat is 3,500 calories. To lose a pound, in essense, you need to eat 3,500 calories less than you need.
I saw 3500 on some pediatrics website, and wolfram alpha said about ~4000. Is there a better source?
Mentor
P: 24,989
 Quote by KingNothing I saw 3500 on some pediatrics website, and wolfram alpha said about ~4000. Is there a better source?
It has always been 3,500 calories since that unit of measurement came into use, to my knowledge.

 Because 3,500 calories equals about 1 pound (0.45 kilogram) of fat, you need to burn 3,500 calories more than you take in to lose 1 pound
http://www.mayoclinic.com/health/calories/WT00011

 It takes 3500 calories to make 1 pound of stored fat.
http://science.education.nih.gov/sup..._ref.htm#sec2c

I have no idea what wolfram alpha is doing to come up with a different value, I have never seen 4,000 calories.
 P: 22 i swim twice a week, hike 10 miles every weekend, but still not losing much weight. in fact, i gained 3 lbs since Thanksgiving, wtf trying to figure out a realistic workout schedule to stay fit and in shape, ideally i'd like to lose 5~10 lbs
Mentor
P: 24,989
 Quote by arabianights i swim twice a week, hike 10 miles every weekend, but still not losing much weight. in fact, i gained 3 lbs since Thanksgiving, wtf trying to figure out a realistic workout schedule to stay fit and in shape, ideally i'd like to lose 5~10 lbs
How many calories do you consume per day? How many calories do you estimate you burn per day? There are guides all over the internet that will help you calculate your calorie expenditure for certain activities based on your gender, height and weight. There are factors to consider such as metabolism, for example, a person with more muscle will normally burn calories more efficiently than a person with more fat.
 P: 22 my typical daily meal intake is like this: 1 cup of oatmeal in the morning 1 footlong sandwich with all the bells and wistles (sometimes buffet or hamburger) dinner i usually skip, just some fruits and maybe a ramen cup noodle i'm a guy in my 30s, weight about 155 lbs, height 5'7''
Mentor
P: 24,989
 Quote by arabianights my typical daily meal intake is like this: 1 cup of oatmeal in the morning 1 footlong sandwich with all the bells and wistles (sometimes buffet or hamburger) dinner i usually skip, just some fruits and maybe a ramen cup noodle i'm a guy in my 30s, weight about 155 lbs, height 5'7''
If you are more muscle than fat, that's not a bad weight for your height. Why are you concerned?
PF Patron
P: 10,394
 Quote by arabianights my typical daily meal intake is like this: 1 cup of oatmeal in the morning 1 footlong sandwich with all the bells and wistles (sometimes buffet or hamburger) dinner i usually skip, just some fruits and maybe a ramen cup noodle i'm a guy in my 30s, weight about 155 lbs, height 5'7''
I'm about your height, about the same weight, and I don't work out nearly as much as you do. I'm betting that you are mostly muscle, not fat. So no need to lose any weight!
P: 5,408
 Quote by arabianights as title says
Keep in mind that the human body stores energy as fat, which has a dietetic calorie content of 9 kcal/g. Thus, to 'lose a pound of fat' implies that 4032 kcal worth of stored fat is used.

Now: loss of fat also entails loss of water (the blood that supplies adipose tissue is decreased), 9 kcal/g is the energy content of some sort of fat burned in a calorimeter and may not be truly equivalent to the fat content of adipose tissue and the process of metabolism, energy is not only stored as fat but also glucose, glycogen, and ultimately ATP.

So, numbers between 3500 and 4000 kcal (or Calories) are *very* reasonable.
Mentor
P: 24,989
 Quote by Andy Resnick Keep in mind that the human body stores energy as fat, which has a dietetic calorie content of 9 kcal/g. Thus, to 'lose a pound of fat' implies that 4032 kcal worth of stored fat is used. Now: loss of fat also entails loss of water (the blood that supplies adipose tissue is decreased), 9 kcal/g is the energy content of some sort of fat burned in a calorimeter and may not be truly equivalent to the fat content of adipose tissue and the process of metabolism, energy is not only stored as fat but also glucose, glycogen, and ultimately ATP. So, numbers between 3500 and 4000 kcal (or Calories) are *very* reasonable.
When you lose weight, you lose glycogen first. You don't burn stored fat first, stored fat is actually the last thing you burn.
P: 5,408
 Quote by Evo When you lose weight, you lose glycogen first. You don't burn stored fat first, stored fat is actually the last thing you burn.
The body typically has a total of 700 g (3000 kcal) worth of glycogen at any moment- it is a tiny fraction of the total amount of stored energy. Although you do indeed catabolize glycogen first to extract energy, glycogen stores are then replenished by conversion of lipid stores.
Mentor
P: 24,989
 Quote by Andy Resnick The body typically has a total of 700 g (3000 kcal) worth of glycogen at any moment- it is a tiny fraction of the total amount of stored energy. Although you do indeed catabolize glycogen first to extract energy, glycogen stores are then replenished by conversion of lipid stores.
Correct,
Mainly I wanted the OP to know that contrary to all off the internet "burn fat instantly" hype that stored fat is the last to go. I'm a woman, we know these things.
P: 5,408
 Quote by Evo I'm a woman, we know these things.
I think I'm offended by your blatant sexism ;)
PF Patron
P: 10,394
 Quote by Evo Correct, Mainly I wanted the OP to know that contrary to all off the internet "burn fat instantly" hype that stored fat is the last to go. I'm a woman, we know these things.
 Quote by Andy Resnick I think I'm offended by your blatant sexism ;)
Be offended later...I need to write this down...Evo...Woman...Fat...got it.
Mentor
P: 24,989
 Quote by Drakkith Be offended later...I need to write this down...Evo...Woman...Fat...got it.
Drakkith...member...soon to be non-member...

 Related Discussions Introductory Physics Homework 3 Introductory Physics Homework 3 Introductory Physics Homework 1 Introductory Physics Homework 4 Biology 8