I had no idea how strong the link between diet and mental health was until recently. A month ago I eased up on my diet - started introducing a little processed sugar and crappy fast food but still what most would consider a decent diet (still lots of good proteins, fruits and veg) and started to see my mental health deteriorate with thoughts of doubting self worth and feelings of loneliness - however just chalked up to normal fluctuations in the mind. Had a normal check up with the doctor and showed my liver tests had gotten a bit worse so I completely cleaned up my diet (cut out all processed sugar and shit and started intermittent fasting) and within a few days my mental health improved dramatically. The change was almost automatic with mental health as soon as I started the completely clean diet. Look after your diet guys!