Cancer cells multiply uncontrollably and rapidly in the body. One of the most important causes of cancer diseases is nutrition. Unhealthy diet, excessive consumption of unhealthy fats and inactivity increase the risk of cancer. For these reasons, a regular and healthy diet and an active life are prerequisites for a healthy life. Sweeteners and unhealthy sugars used today cause cancer cells to be fed. The spread of cancer cells, which are already proliferating uncontrollably and rapidly, is thus accelerated. Nutrition and diet are also very important after the emergence of cancer. Most of the cancer treatments applied cause loss of appetite. For this reason, the patient begins to be malnourished and the already weak immune system becomes even weaker. While cancer treatment continues, it is necessary to have an adequate, healthy and balanced diet in order to strengthen the body's immunity and make cancer treatment more effective.