What is obesity?

Obesity is the medical term used to describe the state of being overweight to the point where it is harmful to your health. The condition is a disease of prosperity; obesity is five times as common now in Europe than it was after the Second World War, when food was rationed. One in five European adults are now considered obese, compared to nearly one in two Americans. Levels of obesity are rising rapidly in Ireland.

Obesity can cause health complications, but perhaps the most damaging aspects of being overweight are psychological — a feeling of inferiority, self-consciousness and shyness, a sense of being unattractive and a lack of confidence. Though many people feel a new lease of life and energy when they lose weight, it is important to remember that there is no such thing as the perfect body.

The most convenient way of measuring obesity is to compare a person’s weight with their height, and this is done using the body mass index. Body mass index is your weight in kilos divided by your height in metres squared. The number for adults should be between 20 and 25, in order for your weight to be considered ideal for your height. Under 20 is underweight, and over 25 is overweight.

The World Health Organisation defines obesity as having a body mass index of 30 or greater, because health problems that are caused by excess weight appear above this level of BMI. Above 35 is serious - or what is known as morbid - obesity, and your chance of dying is significantly increased with a BMI at this level.

Discover your body mass index here.

How does obesity affect health?

There are many physical problems related to obesity, including back problems, skin problems, breathing difficulties, pain in the knees and other joints that have to take the weight (see illustration above). Obese people are more likely to have high blood pressure and diseases related to hardening of the arteries. Obese people are at a far greater risk of developing non-insulin dependant diabetes, gallstones, some types of cancer and an overall increased risk of dying prematurely.

What causes obesity?

Because obesity tends to run in families, many people believe that obesity is hereditary. It can be, but this only increases the chance of someone being obese. It does not dictate that they will be. Obesity develops from a sedentary lifestyle of overeating and lack of exercise. If the calories we receive from eating are not used up, the body stores them in fat. Genes may play their part, but anyone who regularly exercises and eats a healthy diet will stay a healthy weight.

How can I tell if I am obese?

If your BMI level is 30 or higher, then you are obese. While any excess weight is likely to be detrimental to your health, being seriously overweight may require medical attention. If your BMI is over 30, or you are unsure about your weight, consult your GP.

How is obesity treated?

Obesity is caused by lifestyle choices, and these habits need to be broken if an obese person is to stand a good chance of losing weight. There are no quick fixes. Your GP can refer you to a dietician or a nutritionist who will draw up a personal diet plan to help you lose weight. In order to lose weight successfully, it is essential to take up some regular exercise. This need not involve hard and repetitive work in the gym. Walking briskly for 20 minutes each day will help to keep the heart in good working order, and use up some of the excess energy that has been stored as fat.

There are a number of drugs which can cause rapid weight loss results, often by stimulating the body’s metabolism while suppressing the appetite. However, taking a drug for weight loss is a short-term treatment, as it does not confront the underlying behaviour that leads to gaining weight. Consult your GP if you would like to know more about medical treatments for weight loss.

Surgical treatment for obesity is not pleasant and is only considered for people who have a BMI level well over 30, and for whom diet and exercise has proved unsuccessful in shifting the weight. Stomach stapling and jaw wiring should not be considered unless all other options have been exhausted.

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