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# Are there really 7700 calories in a kilo of bodyfat?

Created November 07, 2012 at 12:01 PM

Google searches tell me that I need to burn 7700 calories to burn off a kilo of bodyfat. Is this right?

The reason I'm asking is that I'm trying to dial in my activity multiplier for TDEE calculations without spending weeks or months doing it (purely) experimentally. I'm currently using 1.2 and my diet has been barely below the resulting TDEE, but I've lost 230g of bodyfat per week for the past 7 weeks based on caliper readings and scale. This implies that I'm on a much deeper deficit than barely below TDEE.

Above would equate a deficit of 1760 calories per week if the 7700 cals per kilo of bodyfat statement is true. I would need to increase my TDEE to almost 1.4 to get the numbers to reconcile.

Am I doing it right?

37, male, 183cm, 72kg, calculated BMR 1716. Sedentary, home office, limited walking doing groceries, weight lifting three times a week.

(2957)

on September 07, 2013
at 01:28 AM

I acknowledged as much in my OP, and said this is to be used as a guideline to dial in actual TDEE by experimenting - hopefully faster than pure experimentation. And what thhq said, also talking from experience.

(2957)

on November 07, 2012
at 06:20 PM

I've lost 24kg already, just need to really get my TDEE correct before I start bulking, otherwise I'll balloon.

(10611)

on November 07, 2012
at 05:24 PM

On a long term program the water effect goes away and the calculation is pretty accurate using 7700, provided you count accurately. One nasty effect of weight loss is dropoff in both BMR and exercise effect in direct proportion to body wright. Biking a mile at 150 lbs burns 150/200 = .75 of biking the same mile at 200 lbs.

(10611)

on November 07, 2012
at 05:16 PM

I trusted my body and it told me to eat high glycemic carbs and get fat. Eating paleo is not intuitive. It's a conscious choice not a GUT reaction.

(2957)

on November 07, 2012
at 01:10 PM

The BMR formula you give comes within 10 cals of the one I'm using from rippedbody.jp, so I'm confident that's accurate enough. It's the activity multiplier I'm trying to determine as described in the OP. I mentioned that I'm losing fat at a faster rate then my estimated deficit would suggest. In other words, my calculated TDEE is lower than my real TDEE, and my recomp of -20%/+20% is actually closer to 0/-25% in reality, which is a cut. So I'm suspecting I need to increase my activity multiplier to get a higher calculated TDEE to match my actual TDEE.

(2957)
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1

(10611)

on November 07, 2012
at 05:11 PM

Yes it's right enough. Same thing with your calculated BMR. These provide you with approximate reference points only.

I used to be good at counting, and lost 50 lbs in 6 months doing it. It's never an exact science. I dispensed with activity factors and used BMR plus specific execise, because sitting bone-idle in front of a monitor all day is like REM sleep and doesn't deserve a factor higher than 1.0.

(2957)

on November 07, 2012
at 06:20 PM

I've lost 24kg already, just need to really get my TDEE correct before I start bulking, otherwise I'll balloon.

1

(11488)

on November 07, 2012
at 01:41 PM

You probably have to do less than 7700kcal of exercise, because your body fat won't be converted to mechanical work without some pretty significant losses (principly heat rejection). Off the top of my head, the efficiency is something like 20%.

However, the kcal number you get from gym equipment and HRMs is probably (very roughly) calibrated the amount of your energy reserve (glycogen and fat) that you use, rather than the actual energy you expend.

There is also water stored along with the fat, so if you burn exactly 7700kcal, then you'll lose more than a pound from the scales.

I think that short answer is "more or less yes".

(10611)

on November 07, 2012
at 05:24 PM

On a long term program the water effect goes away and the calculation is pretty accurate using 7700, provided you count accurately. One nasty effect of weight loss is dropoff in both BMR and exercise effect in direct proportion to body wright. Biking a mile at 150 lbs burns 150/200 = .75 of biking the same mile at 200 lbs.

0

(20898)

on November 07, 2012
at 05:11 PM

It's a true statement, but doesn't tell you anything useful. If you burn fat:

Fat + O2 --> CO2 + H2O

then 7700 kCal/kg of energy will be released.

Another true statement is that if you lose 1 kg of body fat then you have by definition had a net deficit of 7700 kCal of energy.

However, neither of those two statements tells you anything about losing weight by starving yourself or exercising more. Those are just true statements relating to physics.

Here are two links on PH where I have gone into more detail.

http://paleohacks.com/questions/143145/losing-weight-low-carb-and-getting-lean-question/143164#143164

http://paleohacks.com/questions/111598/can-u-burn-stored-fat-if-insulin-is-high/111614#111614

0

(2613)

on November 07, 2012
at 04:37 PM

A kilogram of body fat contains about that many calories (not counting water), but I think it's medical hubris to assume that you can dial in your specific caloric needs for the day. Each individual is far too different and each circumstance far too nuanced for any kind of categorical accuracy. I think you're overthinking this. Get some HIIT exercise in, eat Paleo, and trust your body to do the rest.

(2957)

on September 07, 2013
at 01:28 AM

I acknowledged as much in my OP, and said this is to be used as a guideline to dial in actual TDEE by experimenting - hopefully faster than pure experimentation. And what thhq said, also talking from experience.

(10611)

on November 07, 2012
at 05:16 PM

I trusted my body and it told me to eat high glycemic carbs and get fat. Eating paleo is not intuitive. It's a conscious choice not a GUT reaction.

0

(9402)

on November 07, 2012
at 12:11 PM

Yes, 7700 calories (3500 * 2.2) = 1 kg of bodyfat. Not sure what formula you're using, but you can get a more accurate estimate of TDEE if you include lean body mass, e.g. see this recent response:

http://paleohacks.com/questions/159894/how-many-calories-should-i-be-consuming/159899#159899

Bottom line though if you are losing weight (assuming you're trying to) and you feel good, you're probably doing fine it terms of calories.

(2957)

on November 07, 2012
at 01:10 PM

The BMR formula you give comes within 10 cals of the one I'm using from rippedbody.jp, so I'm confident that's accurate enough. It's the activity multiplier I'm trying to determine as described in the OP. I mentioned that I'm losing fat at a faster rate then my estimated deficit would suggest. In other words, my calculated TDEE is lower than my real TDEE, and my recomp of -20%/+20% is actually closer to 0/-25% in reality, which is a cut. So I'm suspecting I need to increase my activity multiplier to get a higher calculated TDEE to match my actual TDEE.