So all of the formulas to figure out your caloric deficits and BMR are based off of your weight.

But that is the weight that includes fat.

What I'm curious about is, doesn't it make more sense to figure out how many calories you need to sustain your internal functions, plus your lean mass and then eat for that, and exclude the fat? Wouldn't that help you burn that fat off faster? Doesn't it tell your body you're getting the calories you need for your general functioning (heart, lungs, etc. etc.) and for the energy your lean mass needs and it can get rid of the fat?

I really feel like you shouldn't be feeding yourself calories that include the BMR for your fat weight, too.

So I'm curious to know if anyone can answer that.

I have on case in point for my theory. Ca$on was fairly heavy before his cut and didn't he lose a massive amount of weight eating 1,600 calories? That's way less than a BMR for someone who was at his initial size. But it worked. It says to me that he was feeding his lean mass and providing the caloric energy he needed for his body to function properly and it burnt the fat off.

Just some thoughts.

I hope others will share their thoughts, too. I'm not a scientist, but I'm a journalist, so I'm a natural contrarian and always asking questions, even if it's only to get a right answer from my dumb thoughts.

So all of the formulas to figure out your caloric deficits and BMR are based off of your weight.

But that is the weight that includes fat.

What I'm curious about is, doesn't it make more sense to figure out how many calories you need to sustain your internal functions, plus your lean mass and then eat for that, and exclude the fat? Wouldn't that help you burn that fat off faster? Doesn't it tell your body you're getting the calories you need for your general functioning (heart, lungs, etc. etc.) and for the energy your lean mass needs and it can get rid of the fat?

I really feel like you shouldn't be feeding yourself calories that include the BMR for your fat weight, too.

So I'm curious to know if anyone can answer that.

I have on case in point for my theory. Ca$on was fairly heavy before his cut and didn't he lose a massive amount of weight eating 1,600 calories? That's way less than a BMR for someone who was at his initial size. But it worked. It says to me that he was feeding his lean mass and providing the caloric energy he needed for his body to function properly and it burnt the fat off.

Just some thoughts.

I hope others will share their thoughts, too. I'm not a scientist, but I'm a journalist, so I'm a natural contrarian and always asking questions, even if it's only to get a right answer from my dumb thoughts.

I was wondering the same thing for a while (im not of normal composition). i found a formula a while back that took body fat % into account but cant find it now :(

I was wondering the same thing for a while (im not of normal composition). i found a formula a while back that took body fat % into account but cant find it now :(

Katch-McArdle

So all of the formulas to figure out your caloric deficits and BMR are based off of your weight...

That's not a true statement--see above.

Although for just BMR, the bodyweight only formulas still do a pretty damn good job on average, with the "on average" being the key statement there.

It's when you start introducing arbitrary stuff like "activity multipliers" where thing are going to start getting whacky. And when you combine that with people who are on far ends of the spectrum (e.g. really high BF%, and maybe more importantly really high BF total), then it might get really whacky.

So that's why it's usually best to just start somewhere reasonable, stay consistent 4-6 weeks, and go from there based on results.

Personally, I went from 222 LB to 152LB sticking to 1200-1500 calories per day. I was bulking at 2500-3000 calories/day for a while, gained up to 165, cut for a little bit down to 161 at 1500-2000, and I'm now starting to get back into a bulk (around 2000 calories per day now, probably will get up to 2500 in a couple of weeks -- been too busy to eat more)

So that's why it's usually best to just start somewhere reasonable, stay consistent 4-6 weeks, and go from there based on results.
Precisely. If X calories/protein/fat whatever isn't working, try adding/subtracting from that number. Those formulas are just a guideline, a place to start. After a while, you will tend to find that the formula isn't the rule for you and most other people.

So all of the formulas to figure out your caloric deficits and BMR are based off of your weight.

But that is the weight that includes fat.

What I'm curious about is, doesn't it make more sense to figure out how many calories you need to sustain your internal functions, plus your lean mass and then eat for that, and exclude the fat? Wouldn't that help you burn that fat off faster? Doesn't it tell your body you're getting the calories you need for your general functioning (heart, lungs, etc. etc.) and for the energy your lean mass needs and it can get rid of the fat?

I really feel like you shouldn't be feeding yourself calories that include the BMR for your fat weight, too.



Makes a lot of sense.
This site calculates BMR based on lean mass:
http://www.naturalphysiques.com/tools.php?itemid=20

Personally, using the above site to calculate bmr has been more accurate than the conventional way for me.

Say you have 150 lbs of lean mass and weigh 170. Another person has 150 lbs of lean mass and weighs 200.

In a given day doing the same activity, walking the same distances, going up the same sets of steps, etc, who would require more calories to function?

The heavier person would because there is more work involved in moving the extra 30 lbs around.

Caloric burn is not linear based on lean mass when as has been said above you factor in activity. So the formulas should take into account some of these things.

But as has also been said above, formulas are just based on averages and we are all different not to mention the fact that depending on how you eat and what you eat you can effect metabolism as well. So experiment to find a good number. Experience is key over time.

This site calculates BMR based on lean mass:
http://www.naturalphysiques.com/tools.php?itemid=20

Interesting site. Here's my favorite part:
"So, what do you do with this? NOTHING! Really. The equation here is just an approximation. Some people will even say that you can take it and multiply it, say, by 1.65 and figure out how many calories you will burn if you are "active". This is still just a shot in the dark."

:)

I read an article that had a calculation that took BF into accunt. Or rather, it calculated a calorie deficit based off your body fat poundage.

The idea was that someone 20% bodyfat could "safely" eat less than someone with 10% bodyfat at the same weight, and this gave you the number. Safely meaning that they were still eating enough to sustain muscle and bodily functions.

So rather than cutting 500cals a day or a 1k or something equally arbitrary, this is the maximum number you can safely cut from your diet.

The equation I have listed in my spread sheet is poundage of fat * 31 = calorie deficit.

So, if sample man is 200 lbs, 6' tall, 20% body fat, we get a BMR of about 2033. Moderately active (x1.55) = 3151.

We apply this calculation to determine a good calorie deficit from this point. 20% of 200lbs = 40 lbs of fat on the body, so the calorie deficit would be 40 * 31 = 1240.

This sample individual, then, would burn the most fat by eating a (3151 active BMR - 1240 calories) 1911 calorie diet; anything less than that could impair health/muscle mass and anything more is suboptimal.

Just for comparison purpose, at 6', 200lbs, 10% body fat, the deficite is(20lbs of fat * 31) 620 calories, so while the active BMR is exactly the same (3151 cals) because height and weight are the same, the calculated deficit is much less and this individual should be eating 2531 calories for optimal weight loss.

Obviously, since his deficit is much less per day, he won't drop as much weight per week. But nor would anyone expect him to, since he's already at 10% bf.

How scientific this is, I don't know (multiplying by a static 31 doesn't seem too too scientific, but sometimes easy is nice). I really need to start saving links to things so I can at least show were I got the info.

...I really need to start saving links to things so I can at least show were I got the info.

Posting this more because I know how annoying it is to lose references, rather than saying this is "the answer" to all of this.

I'll bet you're thinking of this article:

Determining the Maximum Dietary Deficit for Fat Loss (http://www.mindandmuscle.net/articles/lyle_mcdonald/maximum_fatloss?page=0%2C3)


As mentioned above, the paper I’m basing all of this nonsense on was looking at non-exercising dieting of fasting men, not folks who were training...
...
Please keep in mind, however, all of these theoretical calculations sort of pale to real world results. If you’re losing strength in the weight room like crazy, your deficit is too big regardless of what the math works out too, increase them until you stop hemorrhaging strength (and probably muscle). And even if you have to trial and error it a bit, the above should at least give you a starting point


based mostly on this study:

A limit on the energy transfer rate from the human fat store in hypophagia (http://www.ncbi.nlm.nih.gov/pubmed/15615615)


My regurgitation stats are reaching unacceptable levels. :blank:

The idea was that someone 20% bodyfat could "safely" eat less than someone with 10% bodyfat at the same weight, and this gave you the number. Safely meaning that they were still eating enough to sustain muscle and bodily functions.

The equation I have listed in my spread sheet is poundage of fat * 31 = calorie deficit.Yeah, I definitely agree.

I always take goal weight into account when when trying to estimate calories. I think the 500 calorie deficit is a little too simplistic to work by for someone who's not looking to lose equal proportions of fat and lean body mass.

I haven't seen that 31 multiplier before, but it seems to work well in your example.

The science of larger people being able to sustain a larger deficit was discussed on these forums, but I don't remember if it took fat mass into account.

Give me a minute to look it up.

I'll bet you're thinking of this article:

Determining the Maximum Dietary Deficit for Fat Loss (http://www.mindandmuscle.net/articles/lyle_mcdonald/maximum_fatloss?page=0%2C3)That's the one I was thinking of too. It was discussed in the following thread, which I keep meaning to bookmark, but keep having to search for instead:
Good read on determining caloric deficit for fat loss (http://forums.johnstonefitness.com/showthread.php?t=30489&)