India, Sept. 19 -- We all hear a lot about how being overweight can affect your health, but being too skinny isn't always harmless either. Going to extremes and trying to stay super lean can actually take a toll on your body. A new study published on September 14 in the European Association for the Study of Diabetes (EASD) challenges much of what we thought we knew about health and body weight.

Researchers followed nearly 86,000 people, mostly women in their mid-60s, over five years, comparing their BMI to mortality rates. (Also read: Woman who lost 18 kg says 'I started losing weight much faster when I changed this 1 thing in my diet'; shares her tips )

The findings revealed that the "upper-normal" BMI range of 22.5-25 is the sweet spo...