Osteoarthritis (OA) is a progressive, age-related disease characterized by the degradation of the cartilage, abnormal bone remodeling, and joint pain eventually leading to disability. The occurrence of clinically diagnosed OA and the incidence of disability show geographic variations, which suggests that lifestyle and factors such as diet play a vital role in the formation and progression of OA. Obesity is associated with a state of low-grade inflammation and increased plasma concentrations of fatty acids such as the saturated fatty acids (SFA). Importantly, obesity is a major risk factor for the development of OA in both weight-bearing and non-weight-bearing joints. Further, obese individuals bear the full brunt of OA which poses a huge health, social and economic problem, and hence it is essential to increase our understanding of OA and obesity to improve patient care and decrease disease progression. Hence, the current state of knowledge on the relationship between obesity and OA is reviewed, especially the influence of different diets. In particular, we emphasize the role and mechanisms of SFA to cause or worsen OA