Lifestyle not a Determinant of Obesity in Teens?

Now here is a counter intuitive finding from Catherine Sabiston, of McGill University, and P.R.E. Crocker, of the University of British Columbia (UBC) published in the Journal of Adolescent Health earlier this year.

In their study of 900 Vancouver-area 16-18 year-old teenagers in Grades 10 through 12, neither was there a link between body mass index (BMI) values and levels of physical activity nor did the physically active teens eat a markedly healthier diet than their less-active counterparts.

If anything, the heavier teens were actually the ones making healthier food choices while the teens with “healthier” BMI values were no more likely to be physically active than those with higher, “unhealthier” values.

According to Dr. Sabiston (quoted in a press release from McGill University)

“A lot of people are surprised, but when you think about it, BMI doesn’t have a huge impact on physical activity. And in terms of diet, it actually makes sense that someone who is not happy with their body might try to eat more healthily. What this study really says, is that one cannot assume that someone who is physically active necessarily eats a healthy diet – or the reverse, that someone who is more sedentary or has a high BMI by definition eats a diet of junk food.“

To me the findings aren’t all that surprising. I have always maintained that health cannot be simply deducted from the number on your scale and that for every overweight kid who eats mostly junk food and spends every spare minute on his Xbox, there’s a skinny kid out there who’s no better.

The simple truth is that eating healthy and exercising is important at any weight!

On the other hand, just as simply eating poorly and not exercising by no means guarantees weight gain – simply eating healthy and exercising does not guarantee a so-called “healthy” weight.

When everyone eats too much and no one moves, it’s likely the poor kids with the “wrong” genes that pack on the pounds – the kids with the “right” genes are simply lucky and can apparently get away with their lousy lifestyles – who says life has to be fair!

Of course, the words “wrong” and “right” in the previous sentence refer to these genes in today’s world. Until not all too long ago in the history of mankind, the “wrong” genes would have been just “right” and vice versa (talking of thinking in circles).

AMS
Edmonton, Alberta

[Hat tip to Michael Dwyer of CIHR for sending me the McGill press release]