Another weight myth bites the dust in today’s daily research fix. (Of COURSE you were jonesing for another study. There, there, now. Settle down. I’m a gonna take good care of you.) Right after “I’m big boned” the most common excuse for being overweight is “I just have a slow metabolism.” But is it true? What does the research say?
We can all cite a Jack Sprat & His Wife example (side note: why does she not have a name?? I vote for Sybill, I love a good alliteration) from real life. Doesn’t everyone have a friend like my old yoga buddy Kelly who can eat cheeseburgers and candy bars all day every day and not gain an ounce? [insert appropriate skinny-fat warning here] And we probably all know people who subsist on a meager 800 calories a day and yet still battle their weight. But does the research support the idea that obese people have slower metabolisms than lean people?
Nope. Sorry. According to this study
from the Pennington Biomedical Research Center, obese women and lean women have almost the same resting metabolic rate (less than a 100 calorie difference). Your RMR is how many calories you burn just exisiting every day. Any activity on top of that, like exercise or work, requires additional energy and therefore more calories.
The study also examined the women’s activity levels and discovered that the obese women sat 2.5 hours more each day and spent half as much time in activity as lean women. This equaled out to about a 300 cal/day difference.
Problem 1: This study was in no way comprehensive. The sample size was a whopping 20 women (10 in each group). Small sample sizes = less accurate results and less generalizabilty to the greater population.
Problem 2: It’s a chicken and egg thing – were the obese women less active because they were obese? Or were they obese because they were less active? Actually, I suppose it’s more of a vicious cycle with the obesity and the lack of activity feeding into each other. So forget the chickens and eggs. If you still need a mental picture go with cows. They’re much cuter. But still irrelevant. And now you’re hungry. You’re welcome.
Stuff you already pretty much knew: move more, eat less. Rocket science, people! But drop the old adage of a slow metabolism because, barring a health condition like hypothyroidism, chances are it isn’t your metabolism that’s slowing you down.