Colorectal cancer (CRC) is one of the most common cancers in Western countries and remains the second most common cause of cancer death worldwide. Many studies show the importance of diet and lifestyle in the incidence of CRC, as well as in CRC prevention. However, this review summarizes those studies that analyze the impact of nutrition on tumor microenvironment modulation and cancer progression. We review the available information about the effects of specific nutrients on cancer cell progression and on the different cells within the tumor microenvironment. Diet and nutritional status in the clinical management of colorectal cancer patients are also analyzed. Finally, future perspectives and challenges are discussed, with a view to improving CRC treatments by employing nutritional approaches. These promise great benefits and will eventually improve CRC patients’ survival.