Often different diets will suggest combining foods in combinations to get the most nutritional value out of your meal. The principle behind this is not only to provide you with all the necessary nutrients in one meal but also to make sure that foods are efficiently digested so that your digestive system does not have to work in overdrive for proper assimilation of nutrients.
The basis for food combining rests on the argument that the human body is not able to digest more than one concentrated food in one meal.
Typically a concentrated food is something that is not a fresh fruit or vegetable but rather a starch or protein.
Enzymes needed to effectively digest concentrated starches like grains or potatoes require an alkaline environment to do so. On the other hand, protein digestive enzymes need an acidic environment.
So if a concentrated starch along with a concentrated protein, such as potatoes and meat are consumed at the same time, then the resulting enzymes neutralize each other and nothing gets digested effectively.
Effective food combining aims at correcting this problem.
This is done by consuming concentrated proteins, such as eggs and fish with non-starchy vegetables. Non starchy vegetables such as spinach, broccoli, or carrots can be digested in either an acid or alkaline environment so they happily digest with everything.
Another rule of food combining recommends eating grains and concentrated starches with non-starchy vegetables.
In this way grains like quinoa, brown rice, buckwheat or millet combined with starches like potatoes, butternut squash or corn may be eaten with non-starchy, leafy green vegetables. This combination also allows for easy digestibility of food and can be combined successfully with many delicious combinations.
Likewise protein fats such as avocados, olives, seeds, nuts and cheeses should be combined with non-starchy vegetables and acid fruits. Some ideas include putting avocados in green smoothies, nuts and seeds in either desserts or in salads with non-starchy veggies.
As far as fruits are concerned, it is recommended to eat these by themselves without combining with any other food.
This is so because fruits are easily and quickly digested by the human body and when they are eaten with other foods that take longer to digest, the fruit gets caught in the digestive system and ferments, leading to all sorts of digestive complications. Instead eat fruit alone or on an empty stomach.