I'm no expert, but from personal experience, when you only manage to eat toast and a hot dog at lunch, or a granola bar + yogurt and some pasta at dinner along with multiple liters of water for a day because "you just don't feel hungry" and you end up losing so much weight you need to buy new jeans and t-shirts (which you're too depressed to pick out, so your wife buys them for you)- there's something going on.