Tag: weight loss

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My new Sweat Science columns are being published at www.outsideonline.com/sweatscience. Also check out my new book, THE EXPLORER'S GENE: Why We Seek Big Challenges, New Flavors, and the Blank Spots on the Map, published in March 2025.

- Alex Hutchinson (@sweatscience)

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Fitness or fatness: which is more important in determining your health? As I discussed in this Jockology article, some researchers (most notably Steven Blair at the University of South Carolina) believe that most of the health problems we associate with obesity are actually a consequence of poor aerobic fitness. In other words, they argue, it’s okay to be a little portly as long as you’ve exercised enough to have good endurance.

This challenges the basic tenet of old-school, keep-it-simple nutritional thought — that good health is simply a matter of matching the calories you eat to the calories you burn. Can your body tell the difference between a calorie burned through exercise and a calorie avoided through dieting? Well, a really interesting and excruciatingly careful study from researchers at Louisiana State University has just tackled this question.

Here’s the gist: 36 moderately overweight subjects, divided into three groups. One group was the control, and stayed exactly the same during the six-month study. A second group cut their calorie intake by 25 percent, while the third group cut calories by 12.5 percent and increased calories burned through physical activity by 12.5 percent.

As expected, the two intervention group lost exactly the same amount of weight (about 10 percent of their total), and they both shed roughly the same amounts of total fat and visceral fat. This makes sense, because they were both operating under identical calories deficits. Here’s the rub, though: only the exercise group had significant improvements in insulin sensitivity, LDL cholesterol and diastolic blood pressure.

This tells us that a calorie is not just a calorie — it matters how you cut calories. And, as Steven Blair is constantly pointing out, being thin is no guarantee of health if you’re not active. (And, as a nice bonus, it also tells us that it’s possible to drop 10 percent of body mass through a combination of diet and exercise — though it probably helps to have a team of researchers cooking your meals and supervising your exercise!)

THANK YOU FOR VISITING SWEATSCIENCE.COM!

My new Sweat Science columns are being published at www.outsideonline.com/sweatscience. Also check out my new book, THE EXPLORER'S GENE: Why We Seek Big Challenges, New Flavors, and the Blank Spots on the Map, published in March 2025.

- Alex Hutchinson (@sweatscience)

***

A couple of weeks ago, the Globe’s Margaret Wente published an article called “Get fat, live longer,” spurred by a recent Statscan study suggesting that overweight people live longer than normal-weight people. It launched a bit of an Internet firestorm as people forwarded the article around with glee. The article itself was reasonably good, with the exception of one major clunker: she said that “obese” people (BMI 30-35) lived longer, whereas in fact it was just “overweight” people (BMI 25-30) who demonstrated the effect. Still, the message many people took from the article — “get fat, live longer,” — wasn’t quite what the research suggested. So I decided to address a couple of points in this week’s Jockology column:

The question

Statistics Canada says being overweight makes you live longer. Should I stop exercising?

The answer

Let’s start with the facts. In June, Statistics Canada researchers did indeed publish a study in the journal Obesity based on a 12-year analysis of 11,326 Canadian adults in the National Population Health Survey. They found that subjects who were overweight (body mass index of 25 to 30) were 17 per cent less likely to die during the study period than those of normal weight (BMI of 18.5 to 25).

Now on to the interpretation.

These results fit right in with a growing amount of evidence that body weight is not the absolute indicator of health we once thought.

But that doesn’t mean exercise isn’t important. In fact, it turns out that physical fitness is a far better barometer of your long-term health than weight is – and that holds true even for thin but inactive people who thought their fabulous metabolism meant they didn’t need to exercise at all. [read the rest of the column…]

For another very detailed take on this research, check out this post by obesity researcher Travis Saunders on the blog ObesityPanacea.