To clarify: maximum calorie deficit

I received both positive and negative responses concerning my topic on undereating.

I would like to clarify what a person's maximum calorie deficit should be.

It has been found in scientific work that a sedentary person can oxidize 31 calories from adipose tissue every 24 hours.

This means that the more fat you carry, the larger your deficit can be, without catabolized non-fatty tissues (muscle).

Example: A 200 pound man with 20% bodyfat carries 40 pounds of fat, thus he can maintain 40x31 calories = 1240 calorie deficit per day, without losing muscle tissue.

Example: A 200 pound man with 5% bodyfat carries only 10 pounds of fat, thus he can only maintain 10x31 calories = 310 calorie deficit per day.

This is assuming you are sedentary. Adding physical activity will likely increase the body's rate of fat oxidation.

My point is simple: the bigger and fatter you are, the bigger your deficit can be. Large, obese persons can maintain large deficits. The leaner you get, the smaller your deficit should be.

One more point: eating under your BMR will not INITIALLY halt weight loss, but if you continue to eat a very low amount of calories for a prolonged period, your body will fight back.

Link: http://www.bodybuilding.com/fun/core_march_8. htm

This is not something I made up, and I would prefer that this does not turn into an arguement like my other topic.

To help prevent problems, here is an article written along these lines, authored by Lyle McDonald, whose is generally credited to be one of the foremost experts in fat loss anatomy.

http://www.mindandmuscle.net/articles/lyle_mc donald/maximum_fatloss

 

This information was very helpful.  While I understand the effects of the concept explained I had never really understood the concept.  Thank you for sharing your information.

This is great information!  I just bought a scale that shows I am about 38% fat - 207lbs, 5'7... anyway, I was really scared to go over the standard 1,000 calorie deficit, but I'll try it out and see what happens!!

I know it's nit-picky, and it would probably help if I had a link to the study which concluded the 31 cal per pound of fat thing but, I think the study concluded that the maximum amount of energy you can get from a pound of fat is 31 kcals per day, so increasing activity/exercise wouldn't increase that number.  Also, just because you can get 31 kcals/pound of fat doesn't mean that you will get that much, if you aren't training the muscles your body could still decide that it would rather take the energy from the calorically expensive muscle tissue than from the cheap fat tissue.

Original Post by gingerkabureck:

This is great information!  I just bought a scale that shows I am about 38% fat - 207lbs, 5'7... anyway, I was really scared to go over the standard 1,000 calorie deficit, but I'll try it out and see what happens!!

 I'd recommend getting your BF% professionally tested before you make any changes to your diet based on an estimate from a potentially inaccurate scale.

I think you may be misleading people, really. According to your post I should be able to carry a deficit of 2500 or more. Not so!! I had a deficit of about 1500 a day over the summer and was stuck for 8 months.

You may be simply trying to help people but you are leading them in the wrong direction.

"My point is simple: the bigger and fatter you are, the bigger your deficit can be. Large, obese persons can maintain large deficits. The leaner you get, the smaller your deficit should be."

"One more point: eating under your BMR will not INITIALLY halt weight loss, but if you continue to eat a very low amount of calories for a prolonged period, your body will fight back."

When I read the above highlighted I was in awe. You are saying that if you are over fat you can have a huge deficit BUT if you undereat your body will fight back.

Wouldnt it be better if people didnt have HUGE deficits to begin with?!?!?!

 

 

that last article by lyle mcdonald was coarse and totally well informed.  thanks.

If I were to have my max deficit of 3125 I would be very active and burn 6625 calories and eat 3500 for ....sounds somewhat crazy or am I going about it wrong

I'm 6'0" 280 lb with 100.8 lb of fat so 31*100.8=3125

I'm not an expert but if I can actually handle doing that much exercise I suppose it couldn't hurt to try it for a bit ?  I mean if its too much than it should become obvious really quickly right?  Of course I'm not actually sure I can do 3125 in calorie burn a day I'm doing 1400 in 65 mins so 3125 would be a little over 2 hours of exercise

Original Post by raiken3712:

If I were to have my max deficit of 3125 I would be very active and burn 6625 calories and eat 3500 for ....sounds somewhat crazy or am I going about it wrong

I'm 6'0" 280 lb with 100.8 lb of fat so 31*100.8=3125

I'm not an expert but if I can actually handle doing that much exercise I suppose it couldn't hurt to try it for a bit ?  I mean if its too much than it should become obvious really quickly right?  Of course I'm not actually sure I can do 3125 in calorie burn a day I'm doing 1400 in 65 mins so 3125 would be a little over 2 hours of exercise

Am I missing something, why do you need to eat 3500?  And just because you can burn 3125 calories from fat doesn't mean that you will.  If you're doing ton's of cardio or if you aren't exercising, a lot of those calories will be taken from muscle reguardless of how many calories you could potentially take from muscle. 

Um, those links are to a bodybuilding site and I don't want to bulk up just reading it?

Original Post by floggingsully:

Original Post by raiken3712:

If I were to have my max deficit of 3125 I would be very active and burn 6625 calories and eat 3500 for ....sounds somewhat crazy or am I going about it wrong

I'm 6'0" 280 lb with 100.8 lb of fat so 31*100.8=3125

I'm not an expert but if I can actually handle doing that much exercise I suppose it couldn't hurt to try it for a bit ? I mean if its too much than it should become obvious really quickly right? Of course I'm not actually sure I can do 3125 in calorie burn a day I'm doing 1400 in 65 mins so 3125 would be a little over 2 hours of exercise

Am I missing something, why do you need to eat 3500? And just because you can burn 3125 calories from fat doesn't mean that you will. If you're doing ton's of cardio or if you aren't exercising, a lot of those calories will be taken from muscle reguardless of how many calories you could potentially take from muscle.

well i was going on the idea that if I had a calorie deficit of 3125 If most of it were in exercise  I would  classify myself as very active when i input my weight and height and gender along with very active it says I need 3500

If you input your height, weight, activity level, etc, and it says 3500 then it's estimating that you burn 3500 cals per day, not that you need to eat 3500.

Original Post by floggingsully:

I know it's nit-picky, and it would probably help if I had a link to the study which concluded the 31 cal per pound of fat thing but, I think the study concluded that the maximum amount of energy you can get from a pound of fat is 31 kcals per day, so increasing activity/exercise wouldn't increase that number.  Also, just because you can get 31 kcals/pound of fat doesn't mean that you will get that much, if you aren't training the muscles your body could still decide that it would rather take the energy from the calorically expensive muscle tissue than from the cheap fat tissue.

 I see your point. Restriction without weight training may still cause muscle loss.

The idea with exercise is that it will increase blood flow, macronutrient partitioning, and your metabolism, and thus may allow your body to oxidize more than 31 calories per pound of fat.

Original Post by kristinedaqueen:

I think you may be misleading people, really. According to your post I should be able to carry a deficit of 2500 or more. Not so!! I had a deficit of about 1500 a day over the summer and was stuck for 8 months.

You may be simply trying to help people but you are leading them in the wrong direction.

"My point is simple: the bigger and fatter you are, the bigger your deficit can be. Large, obese persons can maintain large deficits. The leaner you get, the smaller your deficit should be."

"One more point: eating under your BMR will not INITIALLY halt weight loss, but if you continue to eat a very low amount of calories for a prolonged period, your body will fight back."

When I read the above highlighted I was in awe. You are saying that if you are over fat you can have a huge deficit BUT if you undereat your body will fight back.

Wouldnt it be better if people didnt have HUGE deficits to begin with?!?!?!

 

 

 Someone that is extremely fat obviously carries alot of fat. Let's say a man is 200 pounds with 20% BF. He has 40 pounds of fat. Thus he can THEORETICALLY maintain a deficit of 1240.

His maintenance calories with moderate activity are about 3300 per day. His BMR is probably 2000 per day. 3300-1200=2100, which is still more than his BMR.

I am not saying people should eat under their BMR. I am saying, quite simply, that the more fat you carry, the faster you can lose it through calorie restriction.

Original Post by raiken3712:

Original Post by floggingsully:

Original Post by raiken3712:

If I were to have my max deficit of 3125 I would be very active and burn 6625 calories and eat 3500 for ....sounds somewhat crazy or am I going about it wrong

I'm 6'0" 280 lb with 100.8 lb of fat so 31*100.8=3125

I'm not an expert but if I can actually handle doing that much exercise I suppose it couldn't hurt to try it for a bit ? I mean if its too much than it should become obvious really quickly right? Of course I'm not actually sure I can do 3125 in calorie burn a day I'm doing 1400 in 65 mins so 3125 would be a little over 2 hours of exercise

Am I missing something, why do you need to eat 3500? And just because you can burn 3125 calories from fat doesn't mean that you will. If you're doing ton's of cardio or if you aren't exercising, a lot of those calories will be taken from muscle reguardless of how many calories you could potentially take from muscle.

well i was going on the idea that if I had a calorie deficit of 3125 If most of it were in exercise  I would  classify myself as very active when i input my weight and height and gender along with very active it says I need 3500

 Lyle McDonald himself says this research should be taken with a grain of salt. I'm not suggesting this is all absolute fact.

The point is that someone of your size can maintain a much larger deficit than a 125 lb female with 15% fat.

Original Post by spirochete:

Um, those links are to a bodybuilding site and I don't want to bulk up just reading it?

 You're kidding, right?

Original Post by imccarthy:

Original Post by spirochete:

Um, those links are to a bodybuilding site and I don't want to bulk up just reading it?

 You're kidding, right?

 Heh, yes. There's a T-nation article floating around here that I really like and I have heard that comment more than once when it's posted. Well, something close to it.

Original Post by imccarthy:

Original Post by raiken3712:

Original Post by floggingsully:

Original Post by raiken3712:

If I were to have my max deficit of 3125 I would be very active and burn 6625 calories and eat 3500 for ....sounds somewhat crazy or am I going about it wrong

I'm 6'0" 280 lb with 100.8 lb of fat so 31*100.8=3125

I'm not an expert but if I can actually handle doing that much exercise I suppose it couldn't hurt to try it for a bit ? I mean if its too much than it should become obvious really quickly right? Of course I'm not actually sure I can do 3125 in calorie burn a day I'm doing 1400 in 65 mins so 3125 would be a little over 2 hours of exercise

Am I missing something, why do you need to eat 3500? And just because you can burn 3125 calories from fat doesn't mean that you will. If you're doing ton's of cardio or if you aren't exercising, a lot of those calories will be taken from muscle reguardless of how many calories you could potentially take from muscle.

well i was going on the idea that if I had a calorie deficit of 3125 If most of it were in exercise  I would  classify myself as very active when i input my weight and height and gender along with very active it says I need 3500

 Lyle McDonald himself says this research should be taken with a grain of salt. I'm not suggesting this is all absolute fact.

The point is that someone of your size can maintain a much larger deficit than a 125 lb female with 15% fat.

 This I can agree with. I just know from personal experience that I cannot carry a deficit of more than 1000 for very long w/o my body fighting back.

The point I took from the 31 cals/pound research was this:  You can burn at most 31 cals of FAT per POUND of adipose tissue per day. Any deficit greater than that will cause you to catabolize muscle tissue.  That's bad, m'kay?

So, let's say a 200 lb man with 20% BF has 40 pounds of fat.  He can burn at most 40*31=1240 calories of FAT per day.  This is a "limiting factor" on fat burn.  But it's not the only one.

Let's say his metabolism is low and his activity is weak.  Since he has 160 pounds of lean mass, he burns 2215 calories per day.  His BMR is around 1850, and we don't want him to go under that.  So his allowed BMR deficit is just 365.  This is another "limiting factor".

Now nutritionists say as a general guideline that people should not attempt to lose more than 1% of body weight per week.  This is a pretty rough estimate, but it does give us another limiting factor.  1% * 200 * 3500 / 7 = 1000 calories.

So, now we have three limiting factors: 1240, 365 and 1000.  Think of them like "maximum speeds", and you can only go as fast as the slowest one.  In this case, that's 365.

So his max allowable deficit is 365 if he continues to do no exercise. (This is the one limiting factor that can be increased immediately, with exercise.)

I put all this in my calculator some time ago to make it easier to figure out.  I'm gradually adding explanation so it makes sense to people.  BMR/RMR Calculator

So I can have a daily deficit of 1400 if I'm very active without losing much muscle?

BMR/RMR Calculator

If I'm reading this right if I burn 1400 Calories in exercise each day 7 days a week I'll lose 2.8 lb a week So eat 2055 and Burn 1400 in exercise for max weight loss?

Extra active gave me the same amount of weight loss a week so theres no point in doing that cause it just has me eat more and burn more for the same weight loss. In case that link doesn't work for some reason the stats I put in are 280 for weight 6'0" for height male and Very Active

If I got something confused please let me know I don't want to mess up

EDIT(I think I'm confused the numbers just aren't working the difference between sedentary and very active is 1400 but when I add 1400 to sedentary which is 3080 it gives me 4420 so 4420-2055 is 2000 something I'm so confused...I really want to burn as much as I can without going overboard but figuring out what to eat and what to burn keeps seeming to get more complicated...I've changed my numbers at least 5 times in the last two days....)

EDIT(ok I noticed 2404 kcal is what its saying for Sedentary while CC says 3080 theres where the big discrepancy is...1452 kcal is a number it says for Activity Deficit which makes it sound like its including the exercise , but than it has 1051 kcal separately for exercise...this is confusing me
Now my thoughts are that I should eat 2055 and burn 1051 in exercise...is that right?)

Thanks for any clarification you can give me

My brain hurts.

I'm thinking we need to start teaching Theoretical Nutritional Math courses at colleges nationwide! It would be more useful than the College Algebra I was forced to take, and it would be only slightly more confusing.

Seriously, though, I appreciate the information.