You've probably seen the headlines about a new study that shows being overweight is actually healthier than being "normal" weight. In short, the study showed that people who are overweight or mildly obese (measured by the Body Mass Index, or BMI) were 6% less likely to have died by the end of a study than those with normal weights.
But does that really mean that overweight people are healthier? A report at NHS Behind the Headlines, a project of the UK health service that analyzes the science behind popular health stories, suggests that there are other factors to take into account. Yes, it's true that several studies have shown that being overweight or mildly obese to not cause higher risk of death than obesity does. Still, being overweight can cause long-term health problems like diabetes that erode quality of life.
In a summary of the findings, NHS explains:
The finding that overweight individuals were at slightly less risk of dying than their normal-weight counterparts had been reported in research before (this is often referred to as the obesity paradox).
Possible explanations why a bit of extra weight may extend life include:
* People with more fat reserves to rely on may survive better if they lose weight due to ill health as they get older.
* Problems associated with being overweight (high blood pressure and diabetes) are picked up and treated earlier in overweight people compared with normal weight, as doctors are more vigilant of risk factors in overweight people. This treatment improves their health overall.
However, it is important to note that these are largely unsubstantiated theories and have not been further explored or proven.
The bottom line is that being obese (all categories combined) increased the chance of dying compared to those with a normal BMI. This was not the case for overweight individuals or the lowest category of obesity (grade 1) on its own.
It is important to consider that individual risk factors for developing disease and death will vary person to person and BMI is only one of many measures used to assess the risk of developing disease in the future.
Even if you choose to ignore the limitations of this research, it would be unwise to interpret its findings as proof that being overweight is ‘healthy' – rather it may be slightly less unhealthy than perceived.
In other words, we should view this study (and any study about health and weight) with a skeptical eye. Still, it does indicate that being overweight is only one risk factor among many when it comes to longevity. People who are overweight can lead long, healthy lives as long as they engage in other healthy activities like regular exercise and include a good proportion of fresh vegetables and fruits in their diet.