I’m a big believer in doing the basics first. They are the building blocks of everything from building a house, writing an essay or driving a car. Without the basics you can get lost constantly chasing your tail. Eating, for me, is one of those basics. Despite little emphasis on the utter importance of eating properly, it’s what we should be doing. It isn’t just about weight and subsequent health issues. A common misconception is to just focus on weight so if you “look” OK and the scales indicate you are at the “right” weight for your height etc. then you must be more or less fine.
Here is an article giving more evidence on the link between diet and depression. Really, why would anyone consider medication before eating the right foods first?