Overweight people don’t live less long, they have more years with impairments

People who are slightly overweight live just as long as people with a normal weight. However, they have to live much longer with impairments. Only serious obesity (a BMI of 35 or over) results in earlier morbidity. This has been revealed by research conducted by demographer Mieke Reuser. She will be awarded a PhD by the University of Groningen on 28 October. Reuser: ‘People who want to get old do not have to diet. However, if you want to be old and healthy, you should keep an eye on your BMI.’  

In the twentieth century, life expectancy in Western Europe, the United States and Japan increased by about thirty years. In recent decades this increase is mainly the result of less morbidity at an advanced age. We are all getting older. The question is, though, are we getting many more ‘good years’, years without illness and impairments? Funnily enough, not much research has been done on this aspect. Demographer Mieke Reuser of the Netherlands Interdisciplinary Demographic Institute (NIDI) and the University of Groningen analysed data from the American Health and Retirement Study for about 30,000 Americans whose health was closely monitored between 1992 and 2004. 

Chubby people getting older

The most surprising result is that overweight and slight podginess do not result in increased morbidity. Life expectancy with overweight (BMI 25-29.9) is even significantly higher for men than if their weight is normal (BMI 18.5-22.9). Only serious obesity (BMI 35 or more) increases morbidity and thus lowers life expectancy. Podgy, well-built men live on average 2 years longer with impairments after they turn 55 than men with normal weight. The difference with women is as much as 3.2 years. 

US: a look at Europe’s future

Given that the percentage of obese people is relatively small, even in the American situation, the effect on the life expectancy of the population as a whole is limited. Mieke Reuser: ‘The US offers us a look into our own future. In Europe, too, we are gradually getting fatter, but we’re not getting any less old. This is leading to an enormous increase in the costs of healthcare. If we want to keep care affordable, we will have to tackle overweight and obesity.’ 

Higher educated people healthy for longer

The research has revealed that more highly educated people live longer and suffer less long from physical and cognitive impairments. Highly educated men aged 55 live on average for 1.1 years with cognitive impairments, less well-educated men 2.7 years. The figures for women are 1.9 and 3.8 years respectively. This research confirms the hypothesis of the ‘cognitive reserve’, that states that more highly educated people can postpone cognitive deterioration and memory loss for longer, by being better able to compensate for damage to the brain cells. The hypothesis states that once more highly educated people are diagnosed with clinical dementia, the stage of brain cell decay is more advanced and they will then die more quickly than people who are less highly educated.

Smokers: impairments for less long

Finally, the research reveals that smoking has the opposite effect to being fat. Because smokers die younger on average, they live for fewer years with physical impairments. Male and female smokers live for 1.3 and 1.4 years less with impairments respectively than men and women who have never smoked. So, if you want to get old, you should stop smoking but you do not have to go on a diet. People who want to get old and stay healthy for a long time should keep an eye on their BMI. Mieke Reuser: ‘With regard to keeping healthcare affordable, it’s not smoking but obesity that is the problem. Smoking will kill you, overweight and obesity make you dependent on others.’ 

Curriculum Vitae

Mieke Reuser (Wamel, 1977) studied economics at the University of Maastricht. She conducted her research at the Netherlands Interdisciplinary Demographic Institute (NIDI) in The Hague and the Population Research Centre (PRC) of the University of Groningen. The research was partly financed by the KNAW and a research grant from Netspar. Reuser will be awarded a PhD by the Faculty of Spatial Sciences of the University of Groningen. Her supervisors were Prof. F. Willekens and Dr L. Bonneaux. She currently works as an actuarial analyst for health insurance company UVIT. The title of her thesis is ‘The effect of risk factors on disability’.  

For more information

Mieke_Reuser hotmail.com