Getting Your Resting Metabolic Rate Tested - 3 Fat Chicks on a Diet Weight Loss Community

purplebanana · 05-12-2005, 01:36 AM

Hi everyone!

I read this article (http://www.msnbc.msn.com/id/5834219/) that talks about how you can get your resting metabolic rate tested either at the hospital or other health facility (or you can purchase your own for a hefty fee

). Testing your RMR will let you know exactly how many calories your body needs to maintain weight. What do you all think of this? Do you think it's accurate? Has anyone tried it? Please let me know!

Thanks!

Mel · 05-12-2005, 08:51 PM

I've had mine done several times using the Body Gem machine and I use it to do the RMR testing at my gym. We charge $45.00.

I just calculated my RMR based on the Harris-Benedict formula in the article and came up with 1252 calories. The last time I did my own BodyGem test (which is never as accurate as someone else doing it!) it came in at 1250. That's pretty darn close! I was surprised, since I haven't used the Harris-Benedict for myself in ages.

When I do the testing at the gym, I don't do the Harris-Benedict in addition; maybe I'll start, just to see the comparisons. What the machine does tell me is whether the RMR for an individual is higher or lower, and by what percentage, from the norm. If I see someone whose RMR is 20% lower, I suggest they talk to their doc about thyroid screening.

For myself, although the expected and and actual numbers match very closely, it really indicates that I have a pretty sluggish metabolism. My measured body fat is 15.5% giving me about 106 pounds of lean body mass. That's well above average for a 125 pound 50 year old. Based on my lean body mass, I should be burning more calories just sitting here, but...I'm not. I'm probably not burning as many while active as a similarly sized person who was not previously obese. See this thread for a discussion of that issue: http://www.3fatchicks.com/forum/showthread.php?t=51478

So...does all of this matter? If you have found an eating/exercising lifestyle that works for you, I really don't think you need to go to the expense of having any metabolic testing done. If you are TRULY eating and exercising in a healthy manner and think you should be in a caloric deficit but you haven't been losing weight for more than a month, maybe you should consider some testing. But you need to be really honest with yourself about your nutrition before you look for metabolic culprits.

Have you tried calculating your RMR based on the Harris-Benedict? I remember in a previous post you said you've been stuck on a plateau for a while.

Mel

tikanique · 05-13-2005, 12:25 AM

So let me see if I got this straight. You test for what a person's metabolic rate is at their current weight and that tells them how many calories they can eat? or do you calculate their rate at their target weight to determine how much they should eat to maintain that lower weight. I did the Harris-Benedict test and got 1336 as the number of calories I'd need for my goal weight and 1449 to maintain where I am now. Also is that calories after you calculate what you burned in exercise or before?

Tiki

purplebanana · 05-13-2005, 01:29 AM

Hi Mel,

I read that thread you put up...and WOW! It's a little depressing but very informative indeed! Well, I AM eating healthy and exercising everyday (or to the best of my ability!

) but am still interested in getting my RMR tested because I simply want to know...I mean, I've used numerous online calculators that give me a daily caloric requirement but have been given very different results, from 1200 calories to 2200 calories a day! I guess I'd just like to know if I'm eating the right amount of calories. I figure if I can't lose anymore weight, I can at least try my best to maintain it...and knowing how many calories my body needs would help.

I've never heard of the Harris-Benedict formula, but I will definitely look into it now! Thanks! I do have one more question: how long have you maintained your weight loss?! Talk to you soon...

Mel · 05-13-2005, 07:42 AM

Tiki and Purple: you have to keep in mind that the Harris-Benedict formula and the BodyGem or MetaCheck Machines predict your RESTING metabolic rate: the number of calories you burn doing nothing. The formula itself doesn't tell you how much you can eat; you have to add in theoretical amounts for activity. And those amounts are just as theoretical as your untested RMR unless you wear a heart monitor that measures caloric burn at all times! It really doesn't take long to get a "feel" for how your body works, though.

Purple, my guess from the wild variation is that some of the calculations are giving you total daily requirements to maintain (2000 sounds close for your age and body weight) and some are giving you RMR (1200 sounds low, but possible for your target).

I'd based your RMR calculations on your current weight- that's the body you live in now. RMR is not the number that you should be working with for your total calorie consumption, but it gives you a baseline.

I maintained my weight loss at 135 pounds for 3 years, then lost another 10-11 pounds 6 months ago.

Mel

techwife · 05-13-2005, 08:11 AM

Well, I don't know anything about this...but I can tell you that if I get a lot of sleep...8-9 hours, I'm down a pound in the morning. Is that a resting metabolic rate at work? Does this mean that mine may or may not be good? Just wondering...