It’s Not The Fat That Matters…

By: David A Fein, MD
Medical Director

‘Tis the season to be eating. And, it’s no secret that most of us put on a little weight around the holiday season. Along with that weight comes a little more guilt and a little more worrying about our health.

We assume that being overweight means more health problems and a shorter lifespan. While there is clearly a link between obesity and many health problems, new research suggests that your weight is not the most important determinant of your health. In fact, almost regardless of your weight, there is something else that is a far more important factor in predicting your longevity.

So, maybe you can go ahead an indulge in a bit of eggnog and some holiday treats provided you focus on what the research shows really matters.

A study published in the December 6, 2011, issue of the medical journal Circulation suggests that your level of physical fitness is a much stronger predictor of longevity that your weight. In fact, in this study, weight had very little effect on overall mortality.

Researchers followed more than 14,000 men for more than a decade. They found that men who were physically fit in their 40’s and maintained their fitness over the next 10 years had nearly a 30% lower risk of dying than men who were out of shape.

Those who improved their fitness level over that time had a 44% lower risk of dying of cardiovascular disease and 40% lower risk of dying from any cause compared with those who stayed unfit.

Body weight, on the other hand, had little impact on the risk of death, especially in those who remained fit. Among the men who became even less fit over time the risk of dying was higher regardless of whether their weight, as measured by BMI, went up or down

Once changes in fitness levels over time were taken into account, there was no significant association between weight gain and mortality. Conventional wisdom, and prior medical studies, suggests that there is a connection between increasing weight and cardiovascular disease.

Prior medical studies have shown being overweight or obese to be a predictor of mortality risk. However, the ability of changes in weight to predict future health is controversial. Some studies have shown that weight loss alone does not significantly alter the risk of early death. Other studies have shown that weight loss may actually be associated with a higher mortality risk. This could be because the weight loss in those studies may have been associated with the onset of other diseases rather than being caused by intentional dieting. In that case, the damage related to being overweight may have already been done. In other cases it is possible that much of the observed weight loss was due to loss of muscle rather than fat.

This study indicates that association between being overweight and increased risk of some health problems, particularly cardiovascular disease, is significantly modified by changes in fitness. . In other words, losing weight doesn’t help if you don’t also become more physically fit at the same time.

So this holiday season you may be able to feel a little less guilty about indulging in a bit of overeating- provided you also keep that New Year’s resolution to finally start getting some exercise.