The underlying cause of obesity and overweight is an energy imbalance between calories eaten and calories consumed.
Globally, there is:
• Increased intake of energy-rich foods high in fat
• An increase in physical inactivity as a result of the increasingly sedentary nature of many job positions, changing modes of transport and increasing urbanization. Changes in diet and physical activity are often the result of changes in the environment and society related to development and lack of support policies in sectors such as health, agriculture, transport, urban planning, environment, food processing, distribution, marketing and education.
What are the common health consequences of overweight and obesity? Elevated BMI is a major risk factor for non-communicable diseases such as:
• Cardiovascular diseases (mainly heart disease and stroke), which were the leading cause of death in 2012;
• Musculoskeletal disorders (especially osteoarthritis – highly disabling degenerative joint disease);
• Some cancers (including endometrial, breast, ovarian, prostate, liver, gallbladder, kidney, and colon).
The risk for these non-communicable diseases is increasing, with increasing BMI. Childhood obesity is associated with a higher chance of obesity, premature death and disability in adulthood. But despite the increased future risks, obese children experience difficulty breathing, an increased risk of fractures, hypertension, and early markers of cardiovascular disease, insulin resistance and psychological effects.