Obesity – A Definition

Obesity. What does that mean?

Definition: The widely accepted measure of Obesity is when the Body Mass Index (BMI) reaches a score of 30 or more.

Click here for an explanation of obesem1BMI and a simple BMI Calculator you can use for yourself. (Opens in a separate window)

Obesity is more than being overweight, it is being so overweight that it threatens health, causing problems as varied as

  • Heart disease
  • Diabetes
  • Arthritis in joints
  • Breathing difficulty
  • Hernia (Abdominal Wall)
  • Hernia (Hiatus)
  • Increasing the chances of some forms of cancer by 60%… 


  • Cancer and Obesity. Untreated obesity has been shown to increase the risks of cancer of the prostate, colon. rectum, ovary and womb, among others. A recent paper published in the Lancet links excessive BMI with 17 out of 22 specific types of cancer, with ‘substantial effects’.
  • The Impact of Bariatric Surgery on Mortality. A recent study by researchers in the USA has found that the risks of dying from any cause at 5 to 14 years afterwards are reduced by 53%.

A lower BMI is associated with extending life-span, the results demonstrate that bariatric surgery reduces mortality and improves survival rates.

JAMA 2015;313:62.70

Obesity is, therefore, likely to cause serious health problems at best, even life-threatening.

Pregnancy and Babies

See also the page on the risks posed by Obesity on Pregnancy

The Fat Mechanism:

All other factors being equal, the equation is rather simple.

Imagine the ‘scales’: The food going in on one side and, on the other, the body’s needs for living and growth and the energy expended (work and exercise).

scalesIf the food going in is greater than the amount needed and used, the surplus gets stored away as fat, deposited all around the body – adding to body weight.


A healthy lifestyle is the first approach. That means a healthy diet and appropriate exercise.

At various stages in life the body has different needs. For example, in childhood, while growing and playing lots of sports the body needs an appropriate supply of energy, and a particular balance of nutrition, eg protein for muscle growth.

In later years, with growth no longer an issue and when living a more sedentary lifestyle, the need for food intake changes. It is quite natural for us to choose to eat what we like and as much of it as we would like. Unfortunately, that is not usuallymonodavids in line with what our bodies NEED. The result is the laying down of fat.

Understanding that mechanism and maintaining the proper balance is the healthiest and easiest way to prevent obesity. The best time to get involved with this is when the first signs of becoming overweight appear. The further we get from that stage, the more work we need to do to get back to a healthy BMI.

Sadly, fighting obesity adequately with a regime of diet and exercise might not be possible for some people. That is where surgical help becomes an option. This web site will explain the various surgical approaches favoured by the London Bariatric Centre. Read on…

Next: Nutrition & Obesity