Biomarker#4: Fat-to-lean

What’s the scariest number you can imagine? The cost of good health insurance? The number of messages in your inbox after a week’s vacation?

No. It’s your percentage body fat at mid-life.

Of all the biomarkers of age, of all the stats that determine how old you really are, biologically, percentage fat and its slender sibling, percentage lean, are among the most significant. The average American loses 6.6 pounds of lean body mass every decade from young adulthood into middle age. At age 45, the rate accelerates. The body of the average 25-year-old woman is 25 percent fat. The body of a (sedentary) 65-year-old woman is, gulp, 43 percent fat (men: 40 percent).

This increase in fat is accompanied by a decrease in muscle mass, which leads to a decrease in strength and general vitality. This condition even has a name – and it’s NOT “getting older.” It’s sarcopenia, Greek for reduction of flesh. It is a game-changer, or a paradigm shift, to consider that something we are accustomed to blaming on chronological age might be a “condition” caused not so much by the number of years we have lived but how we have lived those years.

The fat/ lean ratio is not just about appearance, although it goes without saying that, chunky-thighed, pudgy-cheeked babies notwithstanding, less fat and more muscle can make a body look decades younger than its calendar years. So appearance matters, yes. But there’s far more going on here. The high fat/ low lean thing – sarcopenia – causes, triggers or is closely linked to other markers of aging. Metabolism, for example. Young people, with lower percentages of fat have higher metabolisms. That’s because one pound of fat burns two calories a day, and one pound of muscle burns 35. We’re not slowing down because we’re older. We’re slowing down because we’re, well, fatter.

In addition to slowing down the metabolism – making it, need I add, easier to gain even more fat – high body fat is related to increased glucose intolerance which leads to insulin resistance on the path to type 2 diabetes. Not a road one wants to travel. High body fat ratio is also implicated in elevated bad cholesterol and “old” arteries (ones that do not dilate fully).

But wait! There is a cure for sarcopenia!

And no it is liposuction. No, it is not Human Growth Hormone or DHEA. And, sorry, the cure cannot be found in the supplement/ nutriceutical/ pharmaceutical/ anti-aging commercial marketplace, which is chockful of products that tout “extreme muscle builders” that “mobilize fat” to give “the best body ever.”

If you take moment to follow up those claims like I did, you’ll discover that the top-selling fat-busting/ muscle-building supplement, Hydroxycut, has encountered some major problems, like: jaundice, seizures, cardiovascular problems, liver damage and one documented death. The FDA ordered a recall back in 2009, but the product line is still available everywhere. Don’t buy it.

So what’s the cure? You know what I’m going to say…

Exercise. Movement. Physical activity.

The results are astonishing. And documented.