Often, researching and strictly adhering to a list of things to avoid is orders of magnitude more important and much simpler than researching what to do.
For example, regarding diet, the list of things to avoid includes:
1. Abstain from smoking and alcohol. All forms of tobacco and alcohol are harmful, without exception. Claims that red wine is good for the heart are purely marketing hype and lack rigorous clinical data.
2. Avoid cola and fruit juice (plain water is best), sweets, pastries, and various sauces and condiments.
3. Minimize takeout and dining out. Restaurant food contains more sugar and many uncontrollable, unseen, and harmful ingredients.
4. Allow at least three hours between dinner and bedtime.
5. If unsure, the default option is to eat less or not at all.
Only by doing these things can we meaningfully discuss nutrition; otherwise, it's putting the cart before the horse, self-comfort, and scratching the surface.