Hmmm. Well, I eat quite healthy. I mostly only eat what I make from single ingredients. I rarely eat beef, pork, sugar or gluten. I only use extra virgin olive oil and low heat for cooking. Breakfast is usually made with nut flower, along with walnuts, an egg, cinnamon, and a half of a banana. I then finish it up with some cottage cheese. For lunch I mostly eat vegetables with some skinless chicken breast and gluten free brown rice / corn noodles. I use lots of jalapenos, garlic, onions, and pepper for seasonings. I skip dinner but have a snack which includes slightly soaked raw steel cut oatmeal with some cinnamon. I eat plain dry Cheerios or sauerkraut straight from the can as if they are deserts. It's surprising how your taste buds will adjust once you stop eating sugary crap. I really like my food now. I use zero sugar in any of the flavorings. I only drink water ever, which means no pop, coffee, alcohol, etc, etc, etc. I stay clear of caffeine too.
I also make sure I regularly exercise. I probably should be depressed but I don't seem to be. Sometimes I fell pretty **** good and think to myself, why do I feel good. Life sucks! Ha! ha! Maybe you can be depressed and feel good at the same time as TheRealCallie pointed out. Either way, it's better to feel good.
About a decade I gave up on working and the rat race. I basically quit the normal life. That meant severely tightening up my budget, which meant zero health care until 67. So, I decided at that point to do what I could to be healthy as far as eating and exercise goes. Mentally, according to all that I have read, I'm rotting my brain. I never socialize with anybody. Sometimes I miss it. I miss having a companion. But, mostly I have gotten used to it and prefer to be a hermit now. People just aren't worth all the trouble and drama they cause.
So, it's kind of a long term experiment to see if my mind will rot even though I'm physically healthy. I'll find out at some point. Maybe I'll just hit Alzheimers at an earlier age, which won't matter because I don't have any friends or family to forget. Ha! Ha!
In conclusion, I believe that regular exercise and eating healthy does keep depression away. My self talk and views on life are usually negative, due to experiences, but it doesn't seem to cause me to be depressed. Or, maybe I am depressed but I'm in denial? Is that possible? ****. Maybe I am depressed. Ha! Ha! I should get on the government gravy train and get social security disability. But, it'll be hard when I'm asked how I feel and I say great while I'm thinking about stabbing the guy in the neck and running out of the office to the safety of my home all along with a smile on my face. Ha! Ha! Denied!