Despite current levels of malnutrition across the planet, the World Health Organization (WHO) warns that obesity is a major public health problem worldwide. A global epidemic, obesity is spreading in several countries and, without immediate action, is feared to cause serious health problems over the next few years. Overweight is a condition characterized by excessive body fat accumulation, usually resulting from poor diet and sedentary lifestyles. Behaviours regarding nutrition and physical activity are heavily influenced by social, economic and cultural factors. Contrary to a widespread myth, obesity is not a “problem of the rich”. Not only of the rich, at least: socially and economically disadvantaged people tend to consume more meat, fats and carbohydrates and less fruit and vegetables, and take less care of their appearance and physical health.
The psychological impact of obesity can be devastating: obese people are often isolated and socially stigmatized, which makes social interactions particularly challenging. In particular, overweight children tend to have a difficult relationship with both their bodies and peers, which causes them to shy away from others and lead increasingly sedentary lives.
Several studies have addressed the genetic component of obesity. Given the multifactorial nature of obesity, however, there may also exist combined genetic factors that can positively or negatively affect the ability to lose weight and keep it low.