The stereotype: the jovial fat man (like Santa). Is it true?
A team was looking at obesity and depression. They analyzed 17,200 DNA samples from participants in 21 countries and discovered that people with the FTO gene, associated with obesity, are less prone to depression. The difference is only 8% but it is significant.
The link is presumably in the brain – which regulates body weight and mood.
More evidence of the heritability of both body shape and personality type.