[joeythibault]

there's a correlation between depression and food, but there are also correlations between food and socio economic status. So being low income might also be contributing to mental health (which isn't addressed in the article at all; though they do point out that if there are a lot of takeaway joints near by then the problem is exacerbated...might those areas also be lower income?).

[bpyne]

I'd need to read the article again but I think the study was done on civil employees. I don't know how broad the pay range is for civil employees nor if the authors sampled the full range.

The thing to keep in mind is that Western science made a dichotomy between the mind and body for religious reasons. In reality, they are completely interrelated. Eating unhealthy food will eventually affect your mind: right now it's just not predictable how or to what extent.