As is so often the case, the popular press has run off half-cocked with a complicated statistical study. AP reports, “Fit and fat: US study shows it’s possible.” But it’s not and we already know that. The study that sparked this sensational, if anaccurate headline is abstracted here and appears in full in this week’s Archives of Internal Medicine. The study done at Albert Einstein University shows not that fit and fat are compatible but instead looks at a snapshot from the lives of approximately 6000 adults over 20 as collected by survey and lab reports from 1999-2004. These people were then looked at for the presence of various cardiometabolic risk indicators like systemic inflammation, insulin resistance, high blood pressure and elevated cholesterol and trigycerides.

So, it was found that there is a population of overweight and obese people that do not demonstrate these indicators of risk. There are several points to consider:

• The study population was chosen for their statisical validity and snap-shotted, not observed over time, we know from numerous other studies that it’s not so much a matter of if, but when obesity starts tipping the scales toward high blood pressure and other risks like insulin resistance.
• This study says nothing at all about morbidity (risk of developing disease) or mortality (risk of death) between the study populations.
• The study concludes that there is a high prevalence of the risk factors amongst those that are of normal weight as well as those that are heavier. It does not discount the risks that excess weight carries with it itself.
• The definition of high prevalence needs to be considered since the study itself demonstrates far higher risks among the obese than the normal weight of the risk indicators (> 60% vs. 20-30%).
• Even the authors admit in their conclusion that more study is needed to determine why their findings are as they are.
• Finally, the authors unfortunately chose the turn of phrase “metabolically healthy” and “metabolically abnormal” to represent their categories. This creates confusion especially for lay people and the press when trying to interpret the study findings.

This study does little to change the idea that obesity is itself a risk factor for metabolic diseases. Further, it does underscore the idea that intervening for risk factors such as blood pressure and cholesterol is important in even normal weight individuals as those risk factors can be significantly prevalent.

Aging against the machine requires controlling risk factors for metabolic disease and part of that is keeping weight in a healthy range.