Education. Many people don't realize that kiwis have more potassium than bananas or that lean meats need less to consume (ie 6 oz a serving instead of 10-16oz). There are many books and resources that help you figure out what food choices are best for you.
Water. Most of us don't drink enough. During the chemical break down of all macros (carbs, fats, proteins), water is going in and out of the cell to utilize the nutritional values. It's necessary to proper digestion too. The rule of thumb is half your weight in ounces but if you are outside or increasing physical exercise, you should consider more intake.
Fiber. OMG! Fiber is lacking so bad with the majority of us... it helps the small intestine absorb the nutrients and large intestine push the feces out peacefully. You can supplement with it or get it naturally in foods like beans, berries, broccoli, nuts, some grains.
If you're fasting - smart food choices to break the cycle. IE - protein rich snack that is not too high in overall calories.
Mediterranean diet is one of Dr. Dani's favorites. >>> link: https://my.clevelandclinic.org/health/articles/16037-mediterranean-diet
If keto or keto-like, please have blood work done prior, especially cholesterol. And to not complete this plan for more than 60-90 days.
Sugar... needs to be limited but be aware of "sugar free substitutes" as sometimes you're picking the lesser of evils with the sugar source.
Fruits and vegetables! Eat some form with every meal but have fun with it and try cooking some differently or adding seasonings to increase flavor.
Color your plate - rainbow. I have a goal for my patients and family to eat every color every day.
Don't eat late. Your pancreas likes to stop producing insulin and digestive enzymes after dinner or based on your circadian rhythm, so eating another snack at 11pm is typically stored as fat.