Does weight determine health?

I almost titled this post, “Oh, here we go again.” That’s exactly how I felt when I saw the news last week of the latest study to take a stand on the question of whether it’s possible to be both obese and healthy.

This latest systematic review and meta-analysis, published in Annals of Internal Medicine, used the results from eight studies that looked at death from all causes and/or cardiovascular events (such as heart attacks) in a total of about 61,000 subjects over a 10-year follow up period. Participants were divided into groups by both weight category (normal weight, overweight, obese) and metabolic health (healthy or unhealthy). So, six groups overall.
The metabolically healthy normal weight group had the lowest rate of death or cardiovascular events during follow up. Each of the other groups was compared to this group, and the metabolically unhealthy groups were compared with each other. In general terms, metabolic health was defined as having blood pressure, cholesterol and blood sugar within a normal range. Several things come to mind:
First, population health and individual health are often very different things. For example, body mass index (BMI) was developed by a mathematician many decades ago as a way of assessing the weight distribution of a population. It was not meant to assess the health of an individual person. Yet here we go again, implying that if you have a BMI of 30 or higher, then you are going to die earlier than someone who has a BMI below 25. You, dear reader, are not a statistic. As a society, we need to be focusing on behaviors that promote health instead of placing so much focus on weight. Most weight talk has little to do with health.
Second, the study found that while subjects in the metabolically healthy obese group had almost three times the risk of dying or having a cardiovascular event, compared to the metabolically healthy normal weight group, the metabolically unhealthy normal weight group had almost four times the risk. When all three metabolically unhealthy groups were compared (normal weight, overweight, obese), they had essentially the same risk of one of those unfortunate outcomes.
Third, if the above is true, then why do the media headlines focus only on the metabolically healthy obese group? I saw this time and time again, in headline after headline. In most cases, if you read the full article you saw mention of the risks of being metabolically unhealthy regardless of weight, but you and I both know that a lot of people never get past the headlines. In a few egregious cases (New York Times, I’m looking at you), the article never gave the full context. A shameful example of weight stigma in the media.
Fourth, the study did not account for physical activity or smoking. Regular physical activity is fundamental to good health and disease prevention, for people of all shapes and sizes. Similarly, smoking is incompatible with good health and disease prevention. One reason that you can’t tell how healthy someone is by looking at their size is that size does not necessarily correlate with activity level, especially since exercise does not always lead to weight loss.

Fifth, I find it interesting that blood pressure tended to increase with weight category. Given the prevalence of weight stigma and bias in this country, whether overt (as in job discrimination) or subtle (as in sidelong glances and “helpful” comments), I wonder if the social-psychological stress of living life in a larger body is driving up blood pressure. After all, it’s pervasive racism (overt and subtle), that is likely responsible for the fact that African Americans are at increased risk of high blood pressure (there is no genetic explanation).

Finally, we don’t know what kind of healthcare the subjects were receiving. Considering that more than 69 percent of obese people (in a study conducted through Yale Rudd Center for Food Policy and Obesity) report having been stigmatized by doctors, it’s well within the realm of possibility that the study subjects who fell within that weight category were not getting adequate care for prevention or treatment of health problems that lead to cardiovascular disease and other serious health problems. They may be more inclined to simply avoid the doctor, or they may receive subpar care due to bias. Sad, but true.

And that’s all I’m going to say about that (for now).

Photo Source: Yale Rudd Center for Food Policy & Obesity