What causes obesity? In its simplest sense, the body gains fat when it stores excess energy, and this excess energy arises from consuming more food energy than is burnt in physiological metabolism.
This imbalance in energy consumption and expenditure has several causes: in some cases it may be a genetic disorder but in most cases it arises from living in an environment that allows and encourages low levels of physical activity, extended sedentary behaviour and plentiful consumption of food, especially food rich in energy (e.g. in the form of fats, oils, sugars and starches).
In such ‘obesogenic’ environments it is hard to resist weight gain as we are naturally programmed to minimise effort and store excess food as body-fat. Once we have gained weight, however, it can be difficult to lose it.
Consequences of obesity
People who live with obesity find it stressful and demoralising. Efforts to lose weight are frequently unsuccessful, and there is a continual feeling of hunger. While it is possible to experience apparent good health, excess bodyweight is well-known for increasing the risk of having a stroke or getting heart disease, of developing diabetes, of liver disorders and certain cancers. It also leads to orthopaedic problems with joints and back pain.
In both children and adults, obesity can lead to social stigma and isolation, reducing attendance at school and making it harder to find work and keep a job. In some countries a person with severe obesity may be registered as disabled, and be protected by anti-discrimination legislation.
"Across the world, obesity rates have increased in the last two decades in nearly all age groups. By 2025 it is estimated that 2.7 billion adults and 268 million school-age children will be overweight or obese."
What needs to change?
We need to educate, challenge and raise awareness in order to halt the growth in global obesity.