The increased incidence and survival after treatment contributes to a rising number of people living with a previous cancer diagnosis. Cancer-survivors have an increased risk of developing other lifestyle diseases compared to an age-mathed general population. The aim of this study to examine whether a dietary changes affects health and development of lifestyle diseases after treatment for colorectal cancer. The diet in the study is based on the new Norwegian food-based dietary guidelines, and in addition focus is placed on foods which have been shown to inhibit inflammation or oxidative stress in epidemiological and experimental studies, as well as Norwegian and Nordic foods. The dietary intervention is combined with intensive follow-up to ensure high compliance to the diet.