A study in the US indicates that elderly people may benefit from carrying extra weight.
Researchers from UC Irvine and University of Southern California believe that the body mass index (BMI) should not be followed as a guide to the perfect weight for those over the age of 80.
The scientists claim in the American Journal of Epidemiology that those in their 80s and 90s who posted an 'overweight' 25 to 29.9 BMI score had lower mortality rates than those in the 'normal' range of 18.5 to 24.9.
"We found that what's recommended for everyone else with body mass index measurements isn't necessarily the best for the elderly," commented Maria Corrada, an epidemiologist UC Irvine's School of Medicine.
"It seems that if you are in your 80s or 90s, you may live even longer if you are a bit overweight by BMI standards."
The study also found that those with a BMI of less than 18.5 had the highest mortality rate of the elderly people tested.
Worryingly for those in their 20s who have an "eat now get fit later" attitude, the research found that those who were overweight at the age of 21 had increased mortality rates even if they had lost the weight by later life.