In my post ‘What is Obesity – is it merely about BMI? I had discussed the definition of obesity, as laid down by the WHO, as “A condition of abnormal or excessive body fat accumulation, to the extent that health may be impaired.” People who are obese are at increased risk for many serious diseases and health conditions, compared to those with a normal or healthy weight. However, in my post “Normal weight obesity – a myth or a reality?” I had discounted a widely prevalent myth amongst the general populace that ‘normal body weight always equals healthy weight’. There I had discussed a subset of individuals, among individuals with normal body weight, who develop and suffer from complications of obesity similar to individuals with a more ‘overt’ obesity.
Obesity affects almost every aspect of health, from reproductive and respiratory function to memory and mood. It decreases both the lifespan and the quality of life and increases costs of health care, both at the individual as well as at the national level. It does this through a variety of pathways; some as straightforward as the mechanical stress of carrying extra weight and some as a result of excessive secretion of certain products by enlarged fat cells and ectopic fat depots. The mechanisms by which obesity gives rise to its various ill-effects on health were discussed in my post “Is obesity a disease or a risk factor for other complications?”
However, the good news is that weight loss can reduce some of the risks associated with obesity. Loss of as little as 5 to 10 per cent of body weight provides substantial health benefits to people, and even if they begin to lose weight later in life.