Obesity has been defined by the World Health Organisation as abnormal or excessive fat accumulation that presents a risk to health.

Obesity facts and figures

Causes of obesity

The basic cause of overweight or obesity is an excess of calories from food compared to energy used by the body over time i.e. energy imbalance. The factors that affect energy balance are complex and include behaviour (e.g. breakfast consumption), environment (e.g increased availability of high fat foods) and genetic factors

What are common health consequences of obesity?

Being obese increases your risk of developing a number of serious and potentially life-threatening diseases including:

  • Type 2 diabetes
  • Cardiovascular disease
  • Certain cancers such as breast and colon cancer

Excess weight is also linked to sleep apnoea, infertility, stress, depression, gallstones, complicated pregnancy and arthritis.

Childhood obesity

Childhood obesity is associated with a higher risk of obesity, premature death and disability in adulthood. However, an obese child is not only at increased risk of chronic disease later in life but also at risk in the short term health problems. Obese children are also more likely to suffer various orthopaedic and neurological conditions, breathing disorders, early markers of cardiovascular disease including high blood pressure, insulin resistance and psycho-social problems.

Am I overweight or obese?

There are a number of ways a person's weight can be assessed. The most widely used method is body mass index. Body mass index (BMI) is your weight in kilograms divided by your height in metres squared. You can use the safefood BMI calculator to work out your own BMI:

  • if your BMI is between 25 and 29, you would be considered overweight
  • if your BMI is between 30 and 40, you would be considered obese
  • if your BMI is over 40, you would be considered very obese (known as "morbidly obese")

Another more practical method is to measure your waist. Carrying excess fat around your waist area contributes more to serious health problems than carrying excess fat elsewhere in the body. There is an increased risk of metabolic complications such as insulin resistance, high cholesterol and abnormal fat distribution for men with a waist circumference ≥ 94cm (37 inches) and for women with a waist circumference ≥ 80cm (32 inches).

What can I do to lower my risk?

Overweight and obesity are largely preventable. Supportive environments are key in shaping people’s choices, making the healthier choice of foods and regular physical activity the easiest choice (accessible, available and affordable), and therefore preventing obesity.

At the individual level, people can:

  • reduce their consumption of high fat, salt and sugary foods
  • increase their consumption of fruit and vegetables, as well as legumes, whole grains and nuts
  • engage in regular physical activity (Experts recommend 60 to 90 minutes moderate activity every day)

If you are concerned about your weight please talk to your family GP.