As the prevalence of smoking continues to decline, dietary factors are rapidly becoming the leading preventable cause of disease. Diet and obesity are also leading to a shift in cancer prevalence with increases noted in breast, liver, pancreas, and uterine cancers. Once cancer is detected, obesity is also associated with poorer outcomes with therapy as well as higher morbidity and mortality. Key factors are associated with the link between obesity and cancer including chronic inflammation, change in sex hormones, alteration in insulin-IGF-1 axis, alteration in adipokines, as well as cancer stem cells that are derived from adipose tissue. Because of these associations, a great deal of effort is being placed in implementing lifestyle changes that mitigate obesityassociated factors that contribute to development of cancer, reduce side effects of treatment, and improve survival. Ketogenic diet is emerging as an attractive option in countering obesity-related tumor-promoting factors, as it is associated with weight loss as well as a reduction in insulin resistance and inflammation. Ketogenic diet can also deprive cancer cells of glucose, a fuel source that is predominantly used by many cancer lines through aerobic glycolysis in the setting of dysregulated mitochondria.Current manuscript reviews the theoretical benefits for use of ketogenic diet in cancer as well as the data available from clinical trials.
K E Y W O R D Scancer, ketogenic diet, nutrition, obesity tion in incidence of certain cancers such as lung and colorectal cancer. Unfortunately, in women this decline has been offset by increasing rates of other cancers such as breast, liver, and uterine cancer, thus keeping the overall incidence rates stable. 1 Similarly, in men, reduc-© 2021 American Society for Parenteral and Enteral Nutrition tions in prostate, lung, and colorectal cancer have been noted, whereas rates of cancer of the liver, bile duct, pancreas, and melanoma have increased. 1 Additionally, although cancer mortality has declined, the cost of diagnosing and managing cancer continues to increase and is estimated to account for 7% of all healthcare spending, outpacing all other sectors of healthcare. 3 These changes in cancer trends are leading to an urgency to identify and reverse the increase in incidence of certain types of cancer and reduce overall costs of managing an ever-growing population of cancer survivors. With the decline in tobacco use, dietary factors and obesity are becoming one of the leading causes of cancer. 4 In fact,