I had a Resting Metabloic Rate Analysis done today. I started by fasting for eight hours prior (sleep time), and then went to the office where I stretched out on a cot and breathed into a mask for 20 minutes that was attached to a computer. You are supposed to be as relaxed "resting" as possible, so it was done at seven this morning. The computer scanned my exhalations to determine my daily caloric expenditure. I was expecting maybe 1200.

But here are my results:

Base metablic rate: 1446 C
Thermic/Digestion: 144.6 C
Activities: 289 C

I generally exercise about 30 minutes per day. Exercise: 145 C

Total calories needed: 2024 C

No matter what I do, my body needs minimum 1446 calories per day. I have been at about 1200, which I'm sure put my body in stress (and I wasn't losing weight). In fact, I was told that going under the base metabolic rate puts your body in the starvation mode, essentially slowing down your metabolism, which will cause your base rate to fall.

If I want to lose weight, I need to be between 1446-2024.

Obviously lots of other issues play into this such as body usage of carbohydrates vs. fat and protein. It is food for thought, however, to consider the importance of maintaining a caloric level. Starvation diets can cause a myriad of problems.

Now the only trick is having enough to eat. I'm stuffed and I still need at least 200 calories.

Add about a tablespoon or so of butter (1 tablespoon is a little over 100 calories) to up the calories without stuffing yourself!

yup, or 1 oz of macadamia nuts (about 10-12)

Pretty eye opening, isn't it? I'm really happy you had this done, shazzer and saved yourself a lot of heartache and grief. And I'm very jealous - this kind of testing appeals to the geek in me. I want a test too!

-Nat

Interesting how that RMR works out to about 11x your current weight.

Wow, that's very interesting. Where do you do to have these done? I want one :-)
I wonder if I'm taking in to few calories as well?

I went to this fitness place where they work with a lot of athletes to determine body fat, ideal workouts, and stuff. I think that a lot of larger gyms might know of a similar place or hospital that has one of these machines (all I know for sure is the test is called Resting Metabolic Rate Assessment). If I remember tomorrow, I can call and find out the exact name of the machine and if they know where else they can be found.

It is expensive to do. I paid $110 for the test, but half of that was for my own mask which I can bring the next time.

How excellent, a bit pricey, but to actually know exactly how many cals I need is something I'm dying to know. I'm a bit obsessed with calories!

What I want to know, and I'd love for anyones opinion on the matter, is do you think by 'banking' calories (i.e having less cals through the week and more on weekends) it would have a detrimental effect on the metabolism?

http://www.exrx.net/Calculators/CalRequire.html

found this calculator quite fun. Think mine was quite accurate, according to my observations.

Hello everyone,
Doesn't fitday calculates the amount of calories you need, use ? Or isn't that the same ?

very cool.

according to fitday, a woman of your height and weight has a bmr of 1425. so, i guess their calculations are pretty accurate, at least in the case of normal weight people.

4251 calories? there is NO WAY I could eat that many calories on this plan! I do already add bacon and mayo and ranch to everything trying to UP my calories... besides dont you need to eat jsut under the amount for your current weight if you want to lose weight? I am confused...

Hello Jessica,
Did you look at fitday?
Maybe I am wrong but I think if you look at calories burned / basal / that's the minimum amount of calories your body needs. That's 1987 for you
I could be wrong, so if anybody knows for sure please let us know !
Good luck !

Fitday uses a formula based on the information you give it. How active you are, how tall you are, what type of job you have. It gives you a number for Basal Metabolism and a number for Lifestyle. If you enter information in about activities it gives you that number as well.

I find it pretty accurate, however it can be off by 10-15%, it's just a formula, after all. I know when I first started off at +250 lbs it was on the high side and now it's on the low side, but it's still a good reference.

Keep in mind that the RMR part of fitday is the Basal number - not the total. The total of all the numbers in fitday is what they estimate you burn in a full day, not what your body needs to survive.

Wenzday, I agree, you don't need to eat that much, and good luck trying to! But if you have the odd higher calorie day, don't sweat it - it may actually be a good thing. Keep the body guessing.

In theory to lose fat you need to eat a few hundred calories below what you expend, in total, on any given day. The more you expend vs. the number you eat the more you should lose... but it doesn't always work this well. A deficit that is too great will put stress on your body and fat burning comes to a halt. This is why we often don't lose weight when we eat less calories, too much of a deficit, too much stress.

You have to figure out what works best for you. Trial and error and some calorie fiddling - but only if it's broke. If you're eating a reasonable amount of calories and you're losing, don't mess with it!

-Nat

Plum, thanks for the link to the calorie requirement calculator. Very informative! Now I know my minimum caloric intake (1778).