Can you be obese and healthy?
By Ross Walker
There are an estimated 600 million obese people across the globe. It is estimated that 2.8 million deaths per year are attributed to obesity. There is a clear link between obesity and cardiovascular disease, type 2 diabetes and cancer - not to mention the significant trauma to weight bearing joints.
It’s been suggested, however, that certain people can experience what is known as ‘healthy obesity.’ Healthy obesity refers to obese people who have no evidence of underlying metabolic abnormalities such as insulin resistance, or any cardiovascular risk factors.
Is healthy obesity possible?
A new study from Sweden raises some doubts about the concept of healthy obesity. Although not a large study, this was a very intensive, well-designed protocol that looked at 15 healthy people and then compared them to 50 people who were obese and about to undergo gastric bypass surgery. On testing, 21 of the 50 people were insulin sensitive and the remaining 29, insulin resistant. A technique known as the insulin clamp technique (which is a very intensive and research based analysis for insulin resistance) was performed on all of the subjects in the trial. They also had biopsies of their white abdominal fat. The conclusion of the trial was that all obese people, regardless of their insulin status, showed abnormal gene expression within the white fat, predisposing them to all the above described health concerns.
Another recently published study performed by the International Agency for Research on Cancer (IARC) showed there was a clear link between the duration and severity of obesity and cancer risk. The study looked at just under 74,000 postmenopausal women. Two thirds were overweight or obese and followed up for 12 ½ years. Disturbingly, 60% of the women in this trial who were significantly overweight or obese at some stage during the trial showed that the length and intensity of obesity was linked to cancer risk (and in particular, breast and endometrial cancers).
A recent study has also looked at the link between gallstone disease and cardiovascular disease. Although thin people can suffer gallstones, this is typically related to obesity, and studies show a 23% increase in risk for coronary heart disease in people with gallstones.
The obesity paradox
This brings us to a discussion of the obesity paradox. There has been a large meta-analysis of 2.9m people from 97 trials, with an average follow up of 15 years. This meta-analysis looked at the BMI in varying groups and the associated death risk. Those with a BMI between 20 and 25 had the same death risk as those with a BMI from 30 and 35, or so-called grade 1 obesity. Those with a BMI between 25 and 30 (considered overweight) had a 6% lower death risk compared to the group with a BMI of 20-25, and those with grade 1 obesity. So, once you got to a BMI of between 35 and 40 (considered grade 2 obesity) the death risk increased by 30%. My explanation for the benefits of being slightly overweight includes having somewhat more fat in your cell membranes, which acts as a protective coating against outside toxins.
Another aspect of the obesity paradox is that once obese people develop cardiovascular disease, they seem to fare better than those who are thin. My explanation for this is very straightforward. Thin people who develop cardiovascular disease typically have a much stronger genetic predisposition to the disease, and tend to be younger as well. The more genetic your cardiovascular disease, the more dramatic the presentation, and the worse the outlook. Lifestyle changes do not appear to make as much of a difference in this situation, and therefore, more intensive medical therapy is necessary. When an obese person develops cardiovascular disease, there is obviously so much more room to move, so to speak.
Finally, to give the analogy of cigarette smoking, there are occasionally people who are lifelong smokers who do not appear to come in the way of harm. In the same way, you may occasionally see an obese person that appears relatively healthy. The vast majority of smokers and obese people, however, are at risk for many and varied diseases, and there is no doubt that if any of these people lose a significant amount of weight, their long term health outlook would be so much better.
Published: Thursday, September 01, 2016
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