The ability to absorb food is the main strength of the digestive tract. There are many gastrointestinal diseases that can affect the diet. Inclusion and supplementation are discussed elsewhere. Special attention is given to the liver which controls the energy of starch and lipids and ensures that the peripheral tissues receive the most important supplies. Clinical signs of poor nutrition and the specific impact of poor diet on the digestive tract and liver are addressed with calorie counting treatment for digestive disorders. Finally, a healthy eating approach is presented that includes health assessment and appropriate use of integrated health care and parenting.