Calorie deficit explained? Input needed

alexveksler

This is my first post, so please be easy on me. And if there is already one that is similar, please post a link.

There have been numerous topics about “calorie deficit”, “eat back my calories”, “BMR calculations”, etc… that pretty much got me more confused every time I try to make any sense out of it. So, I spent hours of the research and I think I got this figured out. Below are my findings, so PLEASE tell me if I am totally off course. The example below is my current diet and exercise

What we know: 3500 calories in stored pound of body fat. So, for every 3500 calories I will lose 1LB of fat. From this 1LB there is 75% of fat and 25% of lean tissue. We also know that it is recommended to have 500 calorie deficit in order to have a “good” weight loss.

What I am currently at: My BMR (Basal Metabolic Rate) is 1750 calories per day based on my current weight, activity and age

My current plan: I set my calorie goal to 1200 per day. That leaves me 550 calories deficit (1750 BMR-1200GOAL), which is enough to lose weight. So far I have lost 50LBs.
In addition, I burn 800 calories per day through cardio exercise. I work out every day. Which leaves me total of 1350 calorie deficit. This is where I am confused. I should be losing 1 LB every 2.5 days. 3500/1350 = 2.6 days. Correct? Why am I not losing weight at this rate?

Anyway, with this deficit, roughly every 2.6 days I will burn my 3500 calories, which is amount of 1LB loss. Again, 75% is fat. If you weight lift, you gain muscle back, so you not really losing full LB, only .75LB

Summary: For 15 LB of loss you will need to burn 52,500 calories.
With 500 calories of recommended calories deficit it will take 105 days (52,500/500)

Your input is appreciated.

3dogsrunning

BMR is what your body needs just to survive. On top of that you need to account for your activity using a multiplier.

Harris Benedict Formula
To determine your total daily calorie needs, multiply your BMR by the appropriate activity factor, as follows:

If you are sedentary (little or no exercise) : Calorie-Calculation = BMR x 1.2
If you are lightly active (light exercise/sports 1-3 days/week) : Calorie-Calculation = BMR x 1.375
If you are moderatetely active (moderate exercise/sports 3-5 days/week) : Calorie-Calculation = BMR x 1.55
If you are very active (hard exercise/sports 6-7 days a week) : Calorie-Calculation = BMR x 1.725
If you are extra active (very hard exercise/sports & physical job or 2x training) : Calorie-Calculation = BMR x 1.9


That is your TDEE (total daily energy expenditure). At this number you would neither gain or lose weight. It is this number you take your deficit from, not your BMR.

Also, what is your weight loss goal? The less you have to lose, the smaller your deficit should be.


Or you can just plug it all into MFP, choose the appropriate activity level and follow them. MFP is designed so the activity level does not include exercise, which is why it suggests you "eat back" exercise calories. Or you could choose a higher one that would e appropriate to your anticipated exercise and not "eat " them back.

3dogsrunning

Also the deficit of 500 isnt for everyone. The suggestion is 10-20% deficit from your TDEE. 500 is just an average number.


It is also recommended that you not eat below your BMR. Your deficits are huge. Not always a good thing in the long run.

3dogsrunning

Sorry your post is really long and its hard to read it all on my phone and make points.

Your BMR is 1750. Even if we choose moderate exercise 3-5 times a week, your TDEE would be 2712. You aren't even eating enough to provide your body what it uses just to survive.


For less than 20lbs left to go, your deficit should be .5 lb a week. And when you create huge calorie deficits you lose more muscle as well.

TheVimFuego

<snip>So, for every 3500 calories I will lose 1LB of fat. <snip>

Show me a study where this has been proven to work on a consistent basis in the human body.

I don't mean to be obtuse but that thing might work in theory but the body is more complex than that.

Energy In is not dependent on Energy Out so the premise is fundamentally flawed.

Mindfully eating whole, satisfying, natural foods until you are satisfied will get you closer to health than concentrating on a maths problem when it's actually biology we should be addressing.

reggie2run

bump.

mcarter99

"From this 1LB there is 75% of fat and 25% of lean tissue. We also know that it is recommended to have 500 calorie deficit in order to have a “good” weight loss. "

I've never seen that 75/25 theory. There is no set %.

The 500 calorie deficit recommendation is opinion. Authorities recommend 250-1000.

Your BMR and your exercise are not the only calorie burning you do. See your first response for the multiplier.

You don't lose it exactly as the math implies because (1) it's all estimates, your intake, your burn, all of it, and (2) we don't have a tool at home to measure 'fat loss', just scale weight, which is largely measuring water fluctuations.

I hope your research wasn't done in these forums. There's as much bad info as good. Please read some books or authoritative web sites!

alexveksler

Sorry your post is really long and its hard to read it all on my phone and make points.

Your BMR is 1750. Even if we choose moderate exercise 3-5 times a week, your TDEE would be 2712. You aren't even eating enough to provide your body what it uses just to survive.


For less than 20lbs left to go, your deficit should be .5 lb a week. And when you create huge calorie deficits you lose more muscle as well.

Thanks for all your points. Clearly need to review my plan. I am stuck in a 50LB loss for the past 3 weeks. If I could get to 185, that would be perfect. But I don't know if I can... Although my job is sedentary, I workout 7 days per week with 1 hour of cardio every single day.

And to my defense, I attempted to up my cals a while ago, which simply resulted in weight gain. Not much, but I was up about 5 LB and quit losing.

AnvilHead

If you're eating that far below your BMR and also exercising an hour a day, 7 days a week, you're in a deep hole. Your deficit shouldn't be calculated from BMR, it should be from your TDEE. You might want to read this thread to help you get a better handle on things: http://www.myfitnesspal.com/topics/show/654536-in-place-of-a-road-map-2-0-revised-7-2-12

mcarter99

Depending on how fast you lost that 50 lbs., your body might just be taking a little time and holding water or something. How much higher was your intake when you gained 5 lbs?

yarwell

I've never seen that 75/25 theory. There is no set %.

There must be something lurking in the definition of 3500 - a pound of fat or 454g equates to 4086 calories at 9 cals/g

454* ( 9x + 4(1-x)) = 3500 solves to x = 0.74 ie 74% fat and 26% carbs / protein

ladyraven68

This is my first post, so please be easy on me. And if there is already one that is similar, please post a link.

There have been numerous topics about “calorie deficit”, “eat back my calories”, “BMR calculations”, etc… that pretty much got me more confused every time I try to make any sense out of it. So, I spent hours of the research and I think I got this figured out. Below are my findings, so PLEASE tell me if I am totally off course. The example below is my current diet and exercise

What we know: 3500 calories in stored pound of body fat. So, for every 3500 calories I will lose 1LB of fat. From this 1LB there is 75% of fat and 25% of lean tissue. We also know that it is recommended to have 500 calorie deficit in order to have a “good” weight loss.

What I am currently at: My BMR (Basal Metabolic Rate) is 1750 calories per day based on my current weight, activity and age

My current plan: I set my calorie goal to 1200 per day. That leaves me 550 calories deficit (1750 BMR-1200GOAL), which is enough to lose weight. So far I have lost 50LBs.
In addition, I burn 800 calories per day through cardio exercise. I work out every day. Which leaves me total of 1350 calorie deficit. This is where I am confused. I should be losing 1 LB every 2.5 days. 3500/1350 = 2.6 days. Correct? Why am I not losing weight at this rate?

Anyway, with this deficit, roughly every 2.6 days I will burn my 3500 calories, which is amount of 1LB loss. Again, 75% is fat. If you weight lift, you gain muscle back, so you not really losing full LB, only .75LB

Summary: For 15 LB of loss you will need to burn 52,500 calories.
With 500 calories of recommended calories deficit it will take 105 days (52,500/500)

Your input is appreciated.

your deficit is too large -
http://davfitfitnessforum.forumotion.com/t56-muscle-retaining-factor-1-severity-of-calorie-deficit-by-tom-venuto-a-trusted-friend

your body doesn't like a combination of large deficits and lot's of activity
http://www.bodyrecomposition.com/fat-loss/why-big-caloric-deficits-and-lots-of-activity-can-hurt-fat-loss.html

Work out your total tdee and then take your deficit from there, not from your bmr.
http://www.fitnessfrog.com/calculators/tdee-calculator.html

alexveksler

If you're eating that far below your BMR and also exercising an hour a day, 7 days a week, you're in a deep hole. Your deficit shouldn't be calculated from BMR, it should be from your TDEE. You might want to read this thread to help you get a better handle on things: http://www.myfitnesspal.com/topics/show/654536-in-place-of-a-road-map-2-0-revised-7-2-12

Learn something every day, don't we? Thanks for pointing out this link. I've been reading this and all the supported articles for the past 12 hours.

alexveksler

Sorry your post is really long and its hard to read it all on my phone and make points.

Your BMR is 1750. Even if we choose moderate exercise 3-5 times a week, your TDEE would be 2712. You aren't even eating enough to provide your body what it uses just to survive.


For less than 20lbs left to go, your deficit should be .5 lb a week. And when you create huge calorie deficits you lose more muscle as well.

I have recalculated my goals based on TDEE and NOT the BMR. This was total misconception and thanks again for your input.

I want to take more aggressive approach to calculate more than 20% by selecting "Light activity level", which would put me to TDEE of 2420. With 30%, this will allow me to consume 1694 cals. The reason is, I have not lost any muscle and I have been on the diet since August 16, 2011.

Also, I upped my carb intake to 40 grams. The 30 gram limit was stuck in my head from old Atkins days.

I welcome your input. Thanks

wewon

<snip>So, for every 3500 calories I will lose 1LB of fat. <snip>

Show me a study where this has been proven to work on a consistent basis in the human body.

I don't mean to be obtuse but that thing might work in theory but the body is more complex than that.

Energy In is not dependent on Energy Out so the premise is fundamentally flawed.

Mindfully eating whole, satisfying, natural foods until you are satisfied will get you closer to health than concentrating on a maths problem when it's actually biology we should be addressing.

Agree.

Good post!

mcarter99

I've never seen that 75/25 theory. There is no set %.

There must be something lurking in the definition of 3500 - a pound of fat or 454g equates to 4086 calories at 9 cals/g

454* ( 9x + 4(1-x)) = 3500 solves to x = 0.74 ie 74% fat and 26% carbs / protein

http://www.caloriesperhour.com/tutorial_pound.php

I think it's all still referring to adipose tissue, though, not lean body mass.

"it is commonly said that a gram of fat contains 9 calories. But there are 454 grams in a pound, and 9 x 454 = 4086 calories, not 3500.

The reason for the discrepancy is that body fat, or adipose tissue, contains not only fat, but also other substances including protein, connective tissue, and water. The dietary fat referred to in the nutritional analysis of food is pure.

Looking at it another way, 3,500 / 454 = 7.7 calories. Thus a gram of body fat contains only 7.7 calories versus the 9 calories found in pure fat. It's easy to see that there should be a difference when you consider that body fat contains water, which has no calories.

Because of the differences in the two types of fat, it is appropriate to use the 3500 calories per pound figure when discussing fat "burned" by activity, and the 9 calories per gram figure when discussing the nutritional content of food."