Obesity...A Global Issue?

Obesity is a condition in which the natural energy reserve, stored in the fatty tissue of humans and other mammals, exceeds healthy limits. It is commonly defined as a body mass index (weight divided by height squared) of 30 kg/m2 or higher.

Although obesity is an individual clinical condition, some authorities view it as a serious and growing public health problem. Some studies show that excessive body weight has been shown to predispose to various diseases, particularly cardiovascular diseases, diabetes mellitus type 2, sleep apnea and osteoarthritis.

A large number of medical conditions have been associated with obesity. Health consequences are categorised as being the result of either increased fat mass (osteoarthritis, obstructive sleep apnea, social stigma) or increased number of fat cells (diabetes, cancer, cardiovascular disease, non-alcoholic fatty liver disease). Mortality is increased in obesity, with a BMI of over 32 being associated with a doubled risk of death. There are alterations in the body's response to insulin (insulin resistance), a proinflammatory state and an increased tendency to thrombosis (prothrombotic state).

Disease associations may be dependent or independent of the distribution of adipose tissue. Central obesity (male-type or waist-predominant obesity, characterised by a high waist-hip ratio), is an important risk factor for the metabolic syndrome, the clustering of a number of diseases and risk factors that heavily predispose for cardiovascular disease. These are diabetes mellitus type 2, high blood pressure, high blood cholesterol, and triglyceride levels (combined hyperlipidemia).

Apart from the metabolic syndrome, obesity is also correlated with a variety of other complications. For some of these complaints, it has not been clearly established to what extent they are caused directly by obesity itself, or have some other cause (such as limited exercise) that causes obesity as well. Interesting causes must be needed for this global issue.

Most researchers have concluded that the combination of an excessive nutrient intake and a sedentary lifestyle are the main cause for the rapid acceleration of obesity in Western society in the last quarter of the 20th century.

Despite the widespread availability of nutritional information in schools, doctors' offices, on the internet and on product packaging, it is evident that overeating remains a substantial problem. For instance, reliance on energy-dense fast-food meals tripled between 1977 and 1995, and calorie intake quadrupled over the same period.However, dietary intake in itself is insufficient to explain the phenomenal rise in levels of obesity in much of the industrialized world during recent years.

Eating too many calories for our enery needs must be a major candidate for the main cause of the modern obesity epidemic. According to Dr. Marion Nestle, Professor and Chair of the Department of Nutrition and Food Studies at New York University, US agribusiness now produces 3,800 calories of food a day for every American, 500 calories more than 30 years ago — but at much lower per-calorie costs. Increases in consumption of calorie-dense foods, as evidenced by the growth of fast-food chains and higher soft drink consumption, also point to a higher energy-intake.

The type of food eaten may also play an important role in the rise of obesity. Researchers continue to discover more metabolic and digestive disorders resulting from overconsumption of trans-fats and refined white flour carbohydrates, combined with low fiber intake. These eating patterns are known to interfere with food and energy metabolism in the body, and cause excessive fat storage. Associated health disorders include insulin resistance, type 2 diabetes as well as obesity. Incidence of these "modern" diseases is increasing worldwide.