Should I benchmark my body?

July 22, 2008 8:34 AM

Many MeFites are curious about metabolism, and so am I. I am particularly curious about metabolic rate testing: its accuracy, the experience, and whether it's worthwhile for me.

I am 40, female, 5'8", and a mesomorph with stellar bone density. I've struggled with my weight all my life, although I was not clinically overweight until college and not obese until my mid-20s. I then spiked up to 297; about five years ago, I dropped 50 pounds that have never come back. Three years ago, my doctor advised me to do medically-supervised liquid fasting; I got down to 185 and a size 12, but regained the weight over the next couple of years (I did not realize losing that much also lost my coping strategies for the insane amount of stress I had/have). Over the past few months, I have gotten back on track and am working out more regularly and strenuously than I have ever managed. I'm giving you this background info because I am teetering between confused and worried, thus my AskMe today.

As I said in this comment, I do about 7 hours of hard cardio a week and lift 3x, and have done so since April. I am also monitoring what I eat, primarily by doing Weight Watchers, but I've also started using FitDay to get a detailed breakdown. I range between 1400-1800 calories a day, most of it non-processed "real" food; I have maybe 2 drinks or glasses of wine a week. I have lost two pounds in three months, although I'm down 3 sizes. I swing between worrying that I've completely ruined my metabolism over the past 27 years, and wondering whether I'm actually undereating and triggering starvation mode (again). My gym network offers metabolic testing with the BodyGem tool, and I'm thinking about doing it to get closer to my body's truth than the 10kcal/pound formula. This article (refereed journal) indicates that the BodyGem is more accurate than the formulas.

So, after all that... have you had metabolic testing done? Did the results surprise you, or was it what you thought? Did you use the results to change your eating successfully? Does it need to be done regularly (quarterly/yearly/etc) to be truly useful? I appreciate any info you can pass along - anecdotal, scientific, practitioner stories, you name it.

posted by catlet to health & fitness (7 comments total)

I swing between worrying that I've completely ruined my metabolism over the past 27 years,

You most likely did not "ruin" your metabolism. It's hard to ruin your metabolism. It's also quite difficult to "raise" your metabolism, contrary to what you read and hear. You must build a considerable amount of muscle just to raise it a smidgen. Do you like my technical terms? I read an article in a respected journal about three years ago about the subject of metabolism. I'm trying to find it.

I work in outpatient cardiac rehab. Currently, our hospital is participating in a "Biggest Loser" type weight loss contest for employees. It's multi-faceted. Our facility is the place they use for personal training and exercise. The participants regularly consult with a dietitian and a bariatric nurse. At the start of the program their metabolism was measured. 9 out of 10 people thought their metabolism was "shot" or "low". To their surprise it was normal, or in some people's words, "high". I'll find out what tool our hospital is using to measure metabolism and I'll send you a Mefi mail this week.

Congratulations on going down three sizes. That is quite the accomplishment.
posted by LoriFLA at 9:15 AM on July 22, 2008

I used the BodyGem once. The results were pretty much identical to most online calculators, so I'm not sure if that's a coincidence or what. (My thought at the time was that the BodyGem was crap. It was new then, and I figured it wasn't really testing anything, but was using the same formula as an online calculator. But that was just my personal experience - I don't know anything about its true accuracy.) My stats were 63" height, 140 pounds, BodyGem results: 1420. It wasn't particularly useful for me; I mostly did it out of curiosity.

Maybe you'd find tracking your body fat percentage more helpful, especially if you're losing inches but not pounds. I'd recommend having an expert (i.e. maybe not at the gym) do it, and having it repeated by the same person at regular intervals, maybe quarterly?
posted by peep at 10:20 AM on July 22, 2008

About three years ago, after my dad (successfully) underwent triple bypass surgery, I decided I needed to do something about my weight (5'9", female, > 40, > 300#). I signed up to work with a trainer 1x/week at a local gym. One of the first things they did was use the BodyGem to assess my RMR. It was higher (by about 10% or so) than the online calculators. The initial recommendation from my trainer was to eat around 2000-2200 cal/day. I was astonished since I had previously done "Body for life" and I think my daily calorie consumption was around 1200-1500. Over the next several months, I ended up losing around 65#.

As others have pointed out, if you are losing inches, but not pounds, you are probably losing fat at the same time you are gaining muscle. Since muscle is denser than fat, a pound of muscle is going to take up less space in your body, thus you can have less inches with the same pounds.

A forum I have found to be very useful for weight loss is "3 Fat Chicks" -- a self-help web site started by three sisters who wanted to lose weight. Although it is targeted towards women, men also post and are welcomed. You may want to search on BodyGem over there too.
posted by elmay at 12:57 PM on July 22, 2008

I have lost two pounds in three months, although I'm down 3 sizes.

This is great news! Congratulations on losing fat while becoming stronger and more fit.
posted by ferdydurke at 5:18 PM on July 22, 2008

I work in an exercise physiology based fitness center. We conduct metabolic tests and body composition tests every day. To conduct the metabolic tests we use a metabolic cart and for body composition we use something called a Bod Pod.

I think that knowing your RMR (resting metabolic rate) could only help you. Because you may actually be over eating. When I had my metabolism tested I was a little disappointed in how many calories I should be taking in. I kinda thought I could probably eat more, but was wrong. Keep in mind in order to lose weight you need to take in about 500 calories less than your actual RMR. Increasing your muscle mass and fitness can help your metabolism as well.

As someone suggested above you should test your body composition since you are losing inches and not necessarily pounds. At the facility where I work we usually will do the body composition testing every 6 to 9 weeks to keep track of the progress. We focus more on losing fat mass more so than pounds. We also typically recommend retesting your RMR about every year or so.
posted by peperoxors at 7:10 PM on July 22, 2008

peperoxors: "Keep in mind in order to lose weight you need to take in about 500 calories less than your actual RMR. ."

Er, not really. Unless you are completely and utterly sedentary. Your RMR is the number of calories you burn by EXISTING, and doing nothing more. Not even getting out of bed to pee.

If a person consumed 500 cals less than their RMR, plus lived a moderately active lifestyle (walking around at work, doing a little gardening), plus exercised daily, they would be consuming TOO FEW calories. This is terrible advice.
posted by peep at 9:05 PM on July 22, 2008

Thanks, everyone (including the folks who MeMailed), for the good advice and experiences. I am going to make the BodyGem appointment; if nothing else, extra data points are always welcome! I'd like to baseline my RMR so I can get a handle on caloric expenditure/intake.

I am tracking my bodyfat percentage just on my scale (i.e. not immersion-worthy, but consistent even if not accurate) and it is definitely dropping, so that's something to take to my annual doc visit, even if the scale number isn't changing while I keep buying new jeans.
posted by catlet at 12:48 PM on July 23, 2008