Overweight and Obesity

Overweight and obesity are defined as abnormal or excessive fat accumulation that may impair health.

Body mass index (BMI) is a simple index of weight-for-height that is commonly used to classify overweight and obesity in adults. It is defined as a person’s weight in kilograms divided by the square of his height in meters (kg/m2).

The WHO definition is:

BMI greater than or equal to 25 is overweight.

BMI greater than or equal to 30 is obesity.

BMI provides the most useful population-level measure of overweight and obesity as it is the same for both sexes and for all ages of adults. However, it should be considered a rough guide because it may not correspond to the same degree of fatness in different individuals.

What causes obesity and overweight?

The fundamental cause of obesity and overweight is an energy imbalance between calories consumed and calories expended. Globally, there has been:

  • An increased intake of energy-dense foods that are high in fat, salt and sugars but low in vitamins, minerals and other micronutrients;
  • A decrease in physical activity due to the increasingly sedentary nature of many forms of work, changing modes of transportation, and increasing urbanization.

Changes in dietary and physical activity patterns are often the result of environmental and societal changes associated with development and lack of supportive policies in sectors such as health, agriculture, transport, urban planning, environment, food processing, distribution, marketing and education.

How can overweight and obesity be reduced?

Overweight and obesity, as well as their related noncommunicable diseases, are largely preventable. Supportive environments and communities are fundamental in shaping people’s choices, making the healthier choice of foods and regular physical activity the easiest choice, and therefore preventing obesity.

At the individual level, people can:

  • Limit energy intake from total fats;
  • Increase consumption of fruit and vegetables, as well as legumes, whole grains and nuts;
  • Limit the intake of sugars;
  • Engage in regular physical activity;
  • Achieve energy balance and a healthy weight.

Individual responsibility can only have its full effect where people have access to a healthy lifestyle. Therefore, at the societal level it is important to:

  • Support individuals in following the recommendations above, through sustained political commitment and the collaboration of many public and private stakeholders;
  • Make regular physical activity and healthier dietary patterns affordable and easily accessible too all – especially the poorest individuals.
  • The food industry can play a significant role in promoting healthy diets by:
  • Reducing the fat, sugar and salt content of processed foods;
  • Ensuring that healthy and nutritious choices are available and affordable to all consumers;
  • Practicing responsible marketing;
  • Ensuring the availability of healthy food choices and supporting regular physical activity practice in the workplace.

In simple terms, obesity is being more than one-fifth overweight as compared to the normal weight range Obesity can be defined as excessive enlargement of body’s total quantity of fat. There is no biologic reason for men and women to get fatter as they grow older. Therefore the standard for over fatness for adult men and women should probably be established as men above 20% and women above 30% body fat. The location of adipose (fatty) tissue in the body should also be considered’, fat distributed in the abdominal region poses a greater health risk compared to fat deposited at the thigh, buttocks and over fatness.