There is a great deal of info on the web about health, diet, etc. Here's my two cents. Dr. Greger authors
www.nutritionfacts.org . He reads every scientific medical study published in English and summarizes them in 5-minute videos. I have seen several hundred such videos. To qualify to be on his site, the study must be large-scale, placebo-controlled, peer-reviewed, double-blind, and in English. In other words, it's scientifically valid. To date, here's what the science says:
1. No meat or animal products. No meat, no cheese, no ice cream, no yogurt, nothing from animals. Honey is OK. It's from an insect, not an animal.
2. ALL plant-based products are good for you. The more variety, the better. Potatoes, grains, green veggies, peppers, fruits, nuts, seeds, nuts, etc.
3. No processed food. NONE. If it is packaged in cardboard or cellophane, it's probably not on your menu.
4. Drink only water or green tea. No juices, no sodas, no coffee, no lattes.
5. No free oils. The veggies that contain oils are fine, but not the oil separated from veggies.
If you stick to this, you can eat as much as you want, and you cannot gain weight. It is also recommended you get at least a little exercise every day. Going for a walk about 30-40 minutes each day should do it, although if you want to be healthier, you can go further or do a little weight lifting.
Another good site is
www.drmcdougall.com