September 3, 2013
The increasing prevalence of obesity in the USA and its medical, social, psychological and economic implications has made it a national health crisis. Obesity is predicted to be the number one health problem globally by the year 2025. Although men have higher rates of overweight, women tend to have higher rates of obesity. For both, obesity poses a major health risk for diabetes, cardiovascular disease, hypertension and certain forms of cancer. Obesity is defined as a condition of excess body fat and is associated with a large number of debilitating and life threatening disorders. It is conventionally measured as a body mass index (BMI). The BMI charts classify patient's weight as: underweight if smaller than 20, healthy 20 - 25, overweight 25 - 30, obese 30 - 40, and super-obese 40 and above, signifying increased risk of medical co-morbidities.
Studies indicate that BMI varies for different races. Mortality and Morbidity vary with the distribution of body fat, with the highest risk being linked to excess abdominal fat also known as 'central obesity'. A study by Gopalan revealed that nearly 20% of adults who were not overtly obese still had central obesity, putting them at a greater risk of developing non-insulin-dependent diabetes (NIDDM), hypertension and coronary heart disease (CHD).
With the use of WHO standardized classification of obesity the following data about the worldwide prevalence of obesity was obtained. The prevalence of obesity ranges between 5% in rural China to 75% of adults in Samoa. 22 million children under 5 years of age are overweight. Many countries have experienced a startling increase in obesity over the last 10 - 20 years, and based on current trends predictions have been made that the level of obesity would be 40 - 45% in the USA by 2025, 30 - 44% in Australia, England and Mauritius, and 20% in Brazil. The prevalence of obesity varies between socioeconomic groups as well as between developed versus 'developing countries'. The higher prevalence of obesity in lower socioeconomic groups is thought to be a measure of health awareness and education as well as cost of 'health/diet foods' or joining a gym. The higher educated have the financial stability to maintain their healthy weight.
There also exits a difference in obesity prevalence in developing versus developed countries. In developed countries, lower socioeconomic groups have a higher rate of obesity; however, in developing countries, an increased prevalence of obesity is seen in higher socioeconomic groups. This could be explained by the lower cost of fast foods, higher costs of health clubs and possibly a more sedentary life style in developed countries. In developing countries, the lower socioeconomic groups have to be more physically active, e.g. walk or take public transportation, their diets also tend to be low calorie and they have limited access to fast foods.