Excess adipose tissue in the body is a prevalent public health problem in many parts of the world. Sedentary lifestyle and obesity are among the risk factors that isolated or associated with other risk behaviors, which increase chance of developing of cancer, type 2 diabetes and cardiovascular diseases and can reduce life expectancy. The purpose of this literature review was to analyze evidences for the effects of obesity, of physical activity and cancer. Were searched English-language Medline and PubMed publications about the involvement of the effects and mechanisms that obesity, comorbidities and sedentary lifestyle may contribute to the development and progression of cancer. Scientific evidence shows that exercise has beneficial effects on disease prevention and has also become an important adjuvant in health promotion. Therefore, imbalances of proinflammatory and anti-inflammatory molecules linked to adipose tissue are positively associated with risk of chronic diseases. Physical exercise used as a therapeutic approach is a strategy that will contribute to primary and secondary prevention of diseases, especially if combined with other therapies that control risk factors for the development of cardiovascular and oncological diseases in overweight or obese individuals.