EVERY GP is to be instructed to tell fat patients that they should lose weight, putting doctors in the front line of a new offensive to tackle Britain’s growing obesity problem.

In future GPs will have to treat obesity as if it were any other medical condition and advise the overweight to slim.

It is the first time that doctors have been asked to cajole fat patients, old and young, to eat less, improve their diets and take exercise.

The move by Caroline Flint, the Public Health Minister, is directed in particular at children and young people who need help to lose their excess pounds.

However, GPs have been told not to be too blunt or bossy with the overweight, particularly children. Guidance on how to broach the tricky subject is being sent out to doctors tomorrow. Leaflets for adults and children will be handed out at surgeries and by school nurses.

Giving doctors a frontline role to get the nation into shape comes after efforts to improve school meals and remove junk food from school vending machines.

In an interview with The Times, Ms Flint said that parents had to join in the crusade for healthy living. “Parents have a huge influence over their children and they must say ‘no’ to their children,” she said.

The minister, a mother of three, said that she had to be strict with her own family.

“Like many families I find I have to ration what we have in the house. All mothers know if you buy several packs of biscuits you will come home and find they have all gone. Parents have got to make choices for their children. I know it’s not easy but these messages get through to children.”

She said that she did not want doctors to be pushy with the overweight.

“But GPs will help people get started on diet and exercise. This does not mean someone has to change their life. It’s not about people going on very detailed diets or a very extreme exercise regime. It is not about doctors and ministers telling people what to do. But it is providing support and finding ways to reach people who need help. An obese child has nearly always got obese parents.”

Doctors are advised not to tell a parent: “You know your child should lose weight.” Instead they should encourage a discussion: “How do you feel about your child’s weight?”

GPs should also encourage families to join a leisure centre and children to have at least 60 minutes’ exercise a day.

GPs are also being told to warn people off faddish diets such as the low-carbohydrate, high-protein Atkins diet because the long-term impact on health is not clear. Old-fashioned calorie counting and eating 500 to 600 calories a day less than the body needs is suggested as a realistic way to lose weight. On average men need 2,500 calories and women 2,000 calories a day to stay the same weight.

If a child and his or her parents are unwilling to change their eating and exercise habits, doctors are urged to tread softly because failure to lose weight might affect a child’s self-esteem. In these circumstances GPs are told to weigh the patient and raise the issue of weight at the next visit.

Among other slimming tips are taking a route to avoid walking past a fish-and-chip shop, not keeping crisps in the home and never offering food as a reward or for comfort.

GPs are being urged to use the body mass index (BMI) to show if patients are overweight. A rating of more than 30 is the yardstick for obesity.

BMI is calculated by dividing a person’s weight by the square of his or her height. Charts are to be included in information packs for GPs.

Despite the Government’s attempts to highlight obesity, and efforts by companies to cut levels of salt, fat and sugar in food, a new study shows that people are becoming fatter.

Nearly half of teenage girls and more than a third of teenage boys are overweight or obese, according to the latest Health Survey of England.

In the past year the proportion of boys aged 11-15 who are obese or overweight has risen from 26.9 per cent to 36.4 per cent, while the number of girls has leapt from 29.3 per cent to 45.6 per cent.

A quarter of all adults are dangerously fat.

MEASURING UP

Thus a person weighing 70 kg and 1.7 metres tall would have a BMI of 70 divided by 1.7 squared (2.89) — that is, 24

A BMI of 18.5 to 24.9 is normal, 25 to 29.9 overweight, and over 30 obese

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