Metabolic Rate Calculation

[Mr. Bloom]

This may belong on Nutrition, but I'm hoping for a wider audience of informed folks (maybe a nutritionist???). I'm sorry this is a bit tedious.

Bottom line: I've calculated my metabolic requirement at 2,786 calories/day and this seems VERY HIGH to me. Could this be correct? Am I shrinking too fast?

Here's how I did it:

I've followed the direction of calorielab( http://calorielab.com/faq/idx/7/013/5_Nutrition_and_dieting/article/How_many_calories_do_I_need_per_day.html ) to determine my daily "breakeven" caloric consumption.

So, in the last 7 days, I've:

Consumed 8,915 calories or 1,273/day
Exercised 1,660 calories or 237/day
Lost 3.5 pounds.


Reseach indicates that 1 pound is 3,500 calories. So, to lose 3.5 pounds, I would burn 12,250 calories more than consumed over the 7 day period, or 1,750 calories/day.

My net consumption after exercise is 1,273-237= 1,036/day, but my weight lose implies another 1,750/day to break even.

SO, this implies that my metabolic rate requires 2,786/day which is 1,036+1,750.

The, thinking that 7 days was too short, I did the same thing over 14 days and got a similarly high 2,664/day.

Is this correct? Is it reasonable for a 43 yr old male who is now 175 lbs and 5'7"? My TANITA scale indicates 23% body fat.

[CycleChic06]

I'm trying to sort through your number and calculations, it's kinda confusing. The only thing I could think of, and it might seem a really simple answer, but could it be that the 3.5lbs that you lost would include normal fluctuations in your weight on a daily basis? I find my weight fluctuates between 134 and 137 on a daily basis, even if I weigh myself the same time everyday. Could it be that part of your 3.5lbs weight loss included some of this fluctuation and you actually lost less than you think?

[Mr. Bloom]

Thanks for trying to sort through the tedious math...

I suppose it could be part of a cyclical fluctuation, but when I ran the calculation over a 14 day period when I lost 6.5 pounds, the conclusion was similar.

To add to the confusion, I got my base metabolic rate tested yesterday, and it was measured at 1,610 calories/day (which is sitting in a chair and only breathing). So, this would mean that my normal daily activities (sleeping and a desk job) would have to burn an extra 1,000 calories/day for my calculations to be correct.

[Triskeliongirl]

Clearly your answer doesn't make sense. I think its because the 3.5 lb you lost isn't all fat, some of it is water weight, and your calculation assumes it is all fat. Especially in the early phases of a weight loss program, much of the 'rapid' weight lose is water weight. BUT, clearly your weight is coming done, and clearly 3.5 lb can't be all water weight, so you are losing fat and meeting your goals, so just keep doing what you are doing and BE HAPPY!

[Bluetree]

Mr. Silver,
Sorry if this has been covered elsewhere, but have you seen a doctor or nutritionist before you started dieting?

1200+ calories of intake per day seems very low for a 5-7 man, esp. since you are exercising on top of that. If your caloric intake is too low, your body could react by going into "starvation mode", thus trying to retain any weight it can.. i.e. leaching from muscles instead of fat, etc.

When I was injured and not able to exercise, I had to drop to 1200 calories to maintain my weight... and I was 105 lbs. at the time!!!

[Mr. Bloom]

Mr. Silver,
If your caloric intake is too low, your body could react by going into "starvation mode", thus trying to retain any weight it can.. i.e. leaching from muscles instead of fat, etc.


This is my biggest concern, although:

I don't feel hungry or deprived
I get mixed reactions on whether this should be a concern


At least I can acknowledge there is a good and a bad way...unfortunately, ask 20 people and you can get two 20 different opinions

Thanks for the thoughts and feedback...I think that a visit to the nutritionist would be helpful.

[Bikingmomof3]

This is my biggest concern, although:

I don't feel hungry or deprived
I get mixed reactions on whether this should be a concern



Following up with what Bluetree mentioned-1200 is very low. Some doctors will tell you never to dip below that and with exercise thrown in, you are consuming very few calories a day.

If your body decides it is starving (less food then it wants) your metabolism slows to a halt, you burn muscle, not fat-your body is programmed to keep fat on when it thinks it is "starving".
Yu mentioned not being hungry-this can be one of two things. You body is in starvation mode and that is why you do not feel hungry-slow metabolism, decreased hunger or you are doing everything right.

We are all different, at 5'4, I eat up to 2,000 calories a day, depending on my work outs. Average amount I consume is about 1800.

With your height, age, and most importantly gender-I personally think you are restricting yourself too much. I would strongly advise you seeing a nutritonist to figure out exactly how much you should be consuming a day.

Edited to add: My over priced Tanita scale will one day tell me my body fat is low (trust me, it is defintely not) other days it is just right. The only true body fat measurements I rely on are done by prfessionals. At least the scale function seams accurate. It is actually fun to mess with measurements. Take you body fat measurement, them drink a lot of water. Then do it again. Your water % increases and your body fat % decreases.

I no longer bother with scales unless I play around for geeky scientific reasons. In a given day, my weight alone flucuates to the point I could become seriously depressed. I go strictly by body measurements (thigh, calf, upper arm, etc.) and how my clothes fit.

[hellosunshine]

blimey!im 48.4kg and 5'5" and to maintain my weight i have to eat 3,300 calories a day,any less and i lose weight,so that makes me like a red hot rocket dog metabolic firework in comparison!


i train 2 to 3anda 1/2hrs a day,walk the dog 1 1/2hrs and work long hrs so apart from the internet im not ususally static.


just keep eating if thata what your body wants.fuel your passion!