1. Eat fruit on its own.
And in between meals (except lemon/limes and very low-glycemic sour fruits, which can be eaten with other food).
2. Pair fats only with nonstarchy vegetables.
Fats like avocados, olives, seeds, and nuts are good options. Small amounts of unrefined virgin oils can be paired with everything.
3. Avoid eating more than one protein at a time.
No steak and eggs, no beans and chicken, no surf and turf.
4. Avoid combining starch and proteins.
No rice with chicken, no quinoa with fish, no pasta with meat or dairy.
Note: Beans and legumes are inherently a combination of protein and starch so are often difficult to digest. They are best eaten in small amounts, after proper soaking, and paired only with nonstarchy vegetables.