Overweight and obesity are defined by the WHO as abnormal or excessive fat accumulation that presents a risk to an individuals health.

Overweight and obesity are major risk factors for a number of chronic diseases, including diabetes, cardiovascular diseases and cancer and while it was once an issue only in high income countries, overweight and obesity has now dramatically risen in low- and middle-income countries.Such countries are now facing a "double burden" of disease, for while they continue to deal with the problems of infectious disease and under-nutrition, they are also experiencing a rapid upsurge in chronic disease risk factors such as obesity and overweight, particularly in urban settings.