I was surprised to learn that when you eat, your body does not digest all foods with the same efficiency. The speed or efficiency depends on the types of foods you are eating when you are eating them and the combinations in which you are eating them. If you eat foods that don’t digest well before foods that do, the latter will stay longer in your digestive tract and cause harm. There are simple truths to eating the right things at the right time.
Fruits should ideally be consumed in the morning and by themselves. The reason for this is because fruits digest quickly and combining them with carbs or protein delays their digesting. Fats, in general, combine well with other food types but should be eaten in moderation as they are dense foods and therefore calorie rich.
Starches or carbohydrates can be eaten with vegetables but preferably not with protein.
Proteins take the longest to digest and therefore should not be eaten with starch [the heap of potato that you have with your meat]. Proteins are therefore best eaten with non-starchy vegetables like leafy green vegetables. Proteins can even be eaten just by themselves.
It is best to eat foods like fruits, juices, soups earlier in the day, carbohydrates and vegetables for lunch and proteins for dinner.