Hey all. I have a question for the mathematically minded.

My BMR is 1401 calories

Exercising regularly means my daily calorie intake should be 2662 calories.

To lose 3lbs a week, I should eat 1162 calories. (-500 calories per day per lb of weight to lose per week)

Can anyone explain to me why eating only 238.75 calories a day less than bmr whilst exercising my ass off will burn 3lbs a week, when 3lbs of fat is 12273 calories? (12273 calories devided by 7 days = 1753 calories)...

1753 calories vs 238.75 is a huge difference when trying to work this out.

some of the fats are turned into muscles

some of the fats are turned into muscles

Fat doesn't turn into muscle....

I'm very good at math, but I'm afraid you've confused me. Why are you comparing your caloric intake with BMR? Your total caloric expenditure per day is 2662. Since you are eating 1162 calories, the deficit is 1500 calories per day. That adds up to a 10,500 calorie deficit per week.

Where did you get the 12,273 number?

OK -I'm gonna take a crack at this one.
First off, where did you get a BMR of 1400ish - that seems a bit low, especially since I believe you are over 6' -but I digress

1lb = ~3,500 cals (though there is some debate about this)

To lose 3lb a week (Personally, I would shoot for 2 max, personal experience talking here) requires a 10,500cal defecit.

IF you ate 1400 per day that works out to 9,807cal/week - I'm sure you can see the problem developing - BMR is what you body needs to live, usually it is associated with an activity multiplier, you need that number.

Basically, unless you are doing a ton of cardio, you are not going to lose 3lb of fat per week. The defiecits required are simply too big.

The 1401 BMR is exactly that, it's my stats without the activity multiplier. Would anyone like to explain why an activity multiplier is required? It seems to me that it only increases the amount of time you have to spend in the gym burning off the calories you just ate...

Ok, so for arguments sake 3500 calories = 1lb of fat, that is 10500 calories per week weve gotta burn.

Hmmm, could it be explained as the following:

I start with knowing that I want to burn off that 10500 calories per week, which is 1500 calories a day. I've got to burn AT LEAST that.

so 1500 calories, minus calories burned in the gym = deficit required if cardio session isn't enough?

How does that look?

OK, BMR = the minimum amount of calories necessary for your body to function; i.e. if you sat on the couch all day and didn't move a muscle, your body would burn 1400 cals. I am going to assume that this is not descriptive of your life.
Here is what I do: I generally just use the "light" activity multiplier because it describes performing general activity around the house/office etc - and doesn't really take exercise into the picture.
Say that that calculation came to around 2000 cals per day.
IF you ate 2000 cals and did 500 extra cals of exercise your "net calorie intake" would be 1500. Thus you run a 500cal/day defecit which will result in about 1lb fat loss per week and still give you enough cals to keep essentialy body functions running.

OK, BMR = the minimum amount of calories necessary for your body to function; i.e. if you sat on the couch all day and didn't move a muscle, your body would burn 1400 cals. I am going to assume that this is not descriptive of your life.
Here is what I do: I generally just use the "light" activity multiplier because it describes performing general activity around the house/office etc - and doesn't really take exercise into the picture.
Say that that calculation came to around 2000 cals per day.
IF you ate 2000 cals and did 500 extra cals of exercise your "net calorie intake" would be 1500. Thus you run a 500cal/day defecit which will result in about 1lb fat loss per week and still give you enough cals to keep essentialy body functions running.

so the activity modifier basically represents a normal days routine on top of the bmr and that is to maintain weight with neither gain nor loss. The defecit must come from exercise or reduction in calorific intake, preferably the exercise...

I get ya

:tu:

Craig

Hey all. I have a question for the mathematically minded.

My BMR is 1401 calories

Exercising regularly means my daily calorie intake should be 2662 calories.

To lose 3lbs a week, I should eat 1162 calories. (-500 calories per day per lb of weight to lose per week)

Can anyone explain to me why eating only 238.75 calories a day less than bmr whilst exercising my ass off will burn 3lbs a week, when 3lbs of fat is 12273 calories? (12273 calories devided by 7 days = 1753 calories)...

1753 calories vs 238.75 is a huge difference when trying to work this out.

You say you lose 3 lbs a week, right? That's about the same rate at which I'm losing weight now. But what says that weight is ALL fat? Not going into details (since I'm not sure of them), your body consists of a lot of other things than muscles and fat. Losing weight is far from losing fat. Maybe a pound or so is fat, and the other weight is water or other stuff. While exercising your body's composition changes; muscles grow, carbs are stored/used up, bones thicken...basically a lot of things. Eating less will cause your intestines to get smaller, since they react to getting less food. This will probably get some weight off your body, even though it's not fat.

Now I'm not quite sure exactly what BMR is, but I figure it's your "this is what you need to live" energy. It's just like Two Step says. If you lift your arm to take a pencil, you're burning more energy than you would not reaching for the pencil. Simple things like walking can burn a few hundred kcals every hour. You don't go to the gym to work off the energy you just ate, you eat to GAIN the energy you just worked off in the gym. That's how I see it.

OK -I'm gonna take a crack at this one.
First off, where did you get a BMR of 1400ish - that seems a bit low, especially since I believe you are over 6' -but I digress

Just noticed on a finetoothcombkindofinspection of all the formulas in my spreadsheet that I had actually made a mistake in the calculation of BMR...

To explain, what I had done is devided my height in inches by 2.54, or course, I should have multiplied it to get my height in cm.

:-)

All is good now... I was unsure about my caloric intake, at least now it looks a little normal!

HAHAHA

Just wanted to put my 2 cents in ....

In my experience, trying a 1500 calorie deficit is way too much for your body to handle properly. You'll probably find yourself with less and less energy as your program continues. This was a major mistake I made over the last year. The result is that while I lost weight, my strength significantly decreased and my body shape (while smaller) remained the same.

I'm now on a 1000 calorie deficit and things seem to be going much smoother.

Just wanted to put my 2 cents in ....

In my experience, trying a 1500 calorie deficit is way too much for your body to handle properly. You'll probably find yourself with less and less energy as your program continues. This was a major mistake I made over the last year. The result is that while I lost weight, my strength significantly decreased and my body shape (while smaller) remained the same.

I'm now on a 1000 calorie deficit and things seem to be going much smoother.

It's taken me some time but I've just figured something out.

I have noticed a hell of a lot that people are just multiplying their bodyweight by 10 and leaving their calorie intake at that. They're losing between 2 and 3lbs a week unless they have a strenuous job which entails burning off more calories...

Seems to me, that a very simple way of doing this would be to eat at the rate of bmr, (which seems to be about 10xbodyweight anyway), and burn the amount of calories that would equal the calorie deficit required for loss.

i.e. My calorie deficit appeared at 1500 when aiming for 3lbs a week. To maintain an intake of approx 10xbodyweight (around 220, or 2160 to be precise) I'd have to burn 1500 calories a day. This would seem to be taken up by a normal days routine plus a workout anyway as I seem to burn about 500/550 cals an hour anyway... While that way would require a 3 hour workout (which is exactly the reason why I believe people are only aiming for a lower figure...)

That's just a very simplified way of looking at it though.

1000 cals deficit applies to losing 2lbs a week, that sounds fair enough in anyones books. In answer to your reply though, while 3lbs sounds like a high aim, and in all honesty, yes it probably is, I was noting my intake and was going to adjust from there depending on losses and time in the gym or training at home...

I do like to know the math of things though as I'm a logically minded person... It would be nice to see the efforts 'add up' at the end.

Thank you for your opinion though, the more I learn the better!

This weekend I ate a cheat meal, and I ended up 4lbs heavier as a result. This occured, at least, by my deduction, in part because my metabolic rate was slowed by my heavy dieting for the past month. I've probably done a good deal to ensure starvation hormones were released into my body, and my metabolism was slowed.

As such, I've been interested in the varying equations and research available out there on the metabolic rate. Maybe you need to double check yours? I posted this thread earlier today.

In short, your metabolism changes depending on what you've eaten. You may be flying high at the moment.

Hey all. I have a question for the mathematically minded.

My BMR is 1401 calories

Exercising regularly means my daily calorie intake should be 2662 calories.

To lose 3lbs a week, I should eat 1162 calories. (-500 calories per day per lb of weight to lose per week)

Can anyone explain to me why eating only 238.75 calories a day less than bmr whilst exercising my ass off will burn 3lbs a week, when 3lbs of fat is 12273 calories? (12273 calories devided by 7 days = 1753 calories)...

1753 calories vs 238.75 is a huge difference when trying to work this out.

my metabolic rate was slowed by my heavy dieting for the past month

This is exactly what I think has happened to me. For the past 6 months or so, it turns out my calorie intake wasn't even close to my BMR. Now my metabolism is all messed up. I've been on a much better diet plan for the past two weeks and plan to keep it up. Hopefully I can fix what's been broken.