Can you be obese and healthy — at least metabolically healthy? Probably not, suggests the latest review of the research, which finds even people who are metabolically healthy and obese are at increased risk for an earlier death and risk for cardiovascular disease.
The study — published in the Annals of Internal Medicine — did not look at cancer specifically, but metabolic health is a big topic in cancer risk these days.
Many signs of poor metabolic health are factors for increased cancer risk, as well as type 2 diabetes and heart disease.
If you read this blog you probably know that the heavier you are, the more your risk increases for many cancers, including postmenopausal breast, colorectal, and pancreatic. And obesity brings metabolic issues.
Signs of poor metabolic health include a large waist, high blood pressure, inflammation and high glucose levels. Lately, scientists are working to tease apart how weight and metabolic health affect cancer risk – AICR Nutrition Advisor Karen Collins, MS, RDN, wrote about this a few months ago.
And early in the year, a study made headlines by finding that being pudgy may actually lengthen your life. Obesity did not. We wrote about that here.
This new analysis searched for studies on both metabolic health and weight, looking at the link to death and cardiovascular events, including heart surgery and stroke. The authors found a dozen relevant studies, eight that lasted over ten years and included approximately 61,000 people. The studies used a set of measures to evaluate whether participants were metabolically healthy or not. They used BMI to categorize whether people were at a normal weight, overweight or obese. BMI is a common — but imperfect — measure of body fat.
For studies that lasted only a few years, there was little difference among those at different weights who were metabolically healthy and mortality.
But when the authors focused on studies that lasted over ten years, they found obesity does make a difference. Those who were metabolically healthy and obese had an increased risk for dying earlier and heart disease compared to the metabolically healthy people at a normal weight.
And whatever people weighed — normal, overweight, or obese — the metabolic unhealthy were at increased risk. Compared to people at a normal weight and metabolically healthy, the metabolically unhealthy had from two to three times the risk of premature death or heart disease, even people who were at a “healthy” BMI.
Th authors note that these findings may not apply to everyone, such as the elderly. And the studies did not take into account healthy behaviors, such as being active.
This study will likely add to the debate on whether a person can be healthy and overweight. In this analysis, those who were overweight and metabolically healthy had a similar occurrences of heart disease and death compared to those at a normal weight and who were metabolically healthy.
For now, research is clear that excess body fat increases risk of seven cancers. And obesity increases the risk a person will have poor metabolic health. Overweight and obesity is a cause of approximately 120,000 cancers each year in the United States — that translates to about 320 cancers every day.
For more information on metabolic syndrome, the journal Circulation has a definition paper.
And if you want to know your BMI, use you use our BMI calculator.