For a long time many have assumed they can tell how healthy a person is because of their weight. Now, a major global collaboration of experts is challenging that. 

A Lancet commission has recommended changing the criteria for clinical obesity to move away from BMI as a sole measure of health. 

Also, why a recent review into fluoride in drinking water is flawed — and a higher quality study done in our own backyard. 

And how a genetic study of depression could unlock new treatments for people who are struggling to find medications that work.