Epidemiologic evidence associating obesity and cancer accumulated over last two decades pointing to potentially preventable forms of cancer disease. Observational prospective analyses point to breast and colon cancer as most influenced by obesity-linked lifestyle habits. Other tumor-types can comprise to this group as well (endometrium, esophagus, liver, stomach, thyroid, pancreas, and prostate cancer), according to epidemiological data, but with lesser level of certainty. Randomized studies of lifestyle interventions are still scarce in this area of research, despite being urgently needed. Different pathophysiological mechanisms for obesity-cancer link are proposed in literature. Endocrine factors, deregulated signaling cascades, oxidative stress, and chronic inflammation are implicated as obesity-related carcinogenic processes. Considering growing prevalence of obesity, expert recommendations for lifestyle change (healthy nutrition, physical activity) are widely suggested as a main strategy in primary and secondary prevention of adiposity-related cancers.