When someone is obese, it means they have put on weight to the point that it could seriously endanger their health. This is caused by a combination of eating too many calories and not doing enough physical activity.
Everyone needs to make sure they maintain a healthy weight. Levels of obesity have tripled in England since 1980, and there is no sign of the upward trend stopping.
Currently, over half of women, and about two-thirds of men are either overweight or obese.
Being overweight or obese increases the risk of developing heart disease, Type 2 diabetes, high blood pressure and osteoarthritis.
Obesity causes about 18 million sick days and 30,000 deaths a year in England alone (source: National Audit Office).
To maintain a healthy weight, it's important to follow a balanced diet.
Physical activity has benefits not only for controlling body weight over the long term, but also in controlling appetite. It has beneficial effects on the heart and blood that help to prevent cardiovascular disease.
If you want to lose weight, it's important not to go on a 'crash diet' but to change how you eat and organise a new diet that you can keep to all the time (not just when you're trying to lose weight).
If you go back to eating more calories than you need, you will put the weight back on.
Try:
trimming the fat off meat
choosing low-fat varieties of dairy and other products
increasing your intake of starchy foods instead of fatty ones
eating less of sugary foods
increasing your intake of a variety of fruit and vegetables (aim to eat at least five portions a day)
Sometimes certain medical conditions and drug treatments can cause weight gain. Ask your GP for advice if you are suddenly gaining weight for no apparent reason or if you are on medication.
If you would like advice about losing weight, talk to your GP or a dietitian.
You can find out how to contact dietitians working in private practice on the Dietitians Unlimited website.
You might be interested in the National Audit Office's Tackling Obesity in England. For a copy of this or other Government publications, contact the Stationery Office.
Did you know that if we carry on as we are, nine out of ten of today’s kids will grow up with dangerous levels of fat in their bodies? This will put them at greater risk of serious illnesses such as heart disease, cancer and diabetes in later life.
Change4Life is a nationwide movement that aims to help us all, but especially our kids, eat better, move more and live longer. If your family has not yet signed up to Change4Life, why not do it today? You’ll get lots of tips and ideas to help you make sure your kids are eating well and getting enough exercise.
Everyone needs to make sure they maintain a healthy weight. Levels of obesity have tripled in England since 1980, and there is no sign of the upward trend stopping. 
You can tell from your Body Mass Index, or BMI, whether you are overweight or obese. To work out your BMI use our BMI calculator.
To maintain a healthy weight, it's important to follow a balanced diet.
Visit the Dietitians Unlimited website
Did you know that if we carry on as we are, nine out of ten of today’s kids will grow up with dangerous levels of fat in their bodies? This will put them at greater risk of serious illnesses such as heart disease, cancer and diabetes in later life.