The association between metabolic syndrome and cancer continues to be acknowledged. Metabolic syndrome is a common long-term complication in cancer survivors; on the other hand, findings from several recent meta-analyses suggest that the presence of metabolic syndrome is associated with increased risk of future cancer at specific sites. Approximately one-third of cancer deaths occurring in the USA each year may be caused by unhealthy lifestyle habits, including poor nutrition. Worldwide, diets low in fruits rank third for deaths attributable to individual risk factors. Metabolic syndrome may be a surrogate marker for dietary risk factors for cancer, a sentinel for the deleterious effect of unhealthy diet in susceptible individuals, who may first manifest metabolic consequences (visceral obesity, dysglycemia, hypertension, and dyslipidemia), and then an increased risk of cancer. From the standpoint of preventive oncology, people with the metabolic syndrome should be encouraged, more than sex- and age-matched counterparts, to undergo appropriate cancer screenings.