By FIONA MACRAE

Last updated at 20:15 06 May 2007

The national addiction to junk food is leaving millions malnourished - with some suffering conditions more usually associated with African famine victims.

The number of hospital patients diagnosed with malnutrition has risen by 44 per cent in just five years, with almost 4,000 cases last year.

But experts warn this is just the tip of the iceberg, estimating that up to six percent of the population - or 3.6million people - are malnourished.

They say our growing reliance on fast food, coupled with soaring rates of binge-drinking, means many are lacking the vitamins and minerals essential for health.

The result, in the most extreme cases, is pot-bellies, wasted limbs and emaciated bodies - all conditions more usually associated with famine victims in the developing world.

While malnutrition can be fatal, in more mild forms it can cause a host of symptoms that impact on every day life, from hair loss and muscle wastage to food cravings and lethargy.

No age-group is exempt and treatment of malnutrition cost the NHS more than £7.3billion a year - more than twice the annual obesity bill.

Joining forces to highlight the scale of the problem, doctors and celebrity chefs warned that obesity was far from the only consequence of a fast food diet, high in fat and sugar and low in vitamins and minerals.

Dr Mike Stroud , a University of Southampton expert who helped draw up government malnutrition guidelines, said: "The modern diet is not providing enough vitamins.

"Malnourishment is going to make you more vulnerable to illnesses and less able to cope with them."

Dr Alistair McKinlay, an Aberdeen University gastro-enterologist and one of Britain's leading authorities on malnutrition, said: "If you are young an well, you can still end up malnourished.

"In 75 per cent of people, the problem is not identified."

Gordon Ramsay said it was up to parents to educate their children on healthy eating.

The chef, who is a father of four, said: "If we are going to be a healthy nation, then you've got to discipline the parents.

"Children eat with their eyes. They're lazy.

"If you don't tell them about what they're eating, trust me, they will eat as much crap as they can when they get home.

"They get connected to junk food in a way that becomes obsessive."

Jamie Oliver, who has relentlessly campaigned to improve the quality of school dinners, told the Independent on Sunday: "I think parents are unaware of how much junk their kids are eating and drinking.

"As well as the frightening rise in obesity, there's a growing number of kids, of whatever shape and size, that simply aren't getting enough nutrients like iron, calcium and vitamins.

"It's having a huge effect on their brainpower, behaviour and ability to concentrate and learn at school."

The warning follows estimates that 40 per cent of hospital and care home residents are malnourished, with staff lacking the time to help the weak and elderly eat meals which are often unappealing

The British Association for Parenteral and Enteral Nutrition, a charity which tries to increase awareness of malnutrition, called for the screening of all hospital patients to be made mandatory.

Spokesman Rhonda Smith said: "We want more people to be identified as being clinically malnourished, so that appropriate treatment pathways can be put in place."

Conservative peer Lord Hanningfield, who obtained the hospital figures, said: "It is time patients were routinely screened for malnutrition and offered specialist nutrition support."

The call comes as Britain fights a rising tide of obesity.

A growing reliance on fast food and time-saving technology has led to the UK developing the worst weight problem in Europe, with almost a quarter of adults classed as obese.

Children fare little better, with obesity figures doubling among six-year-olds and trebling among 15-year-olds in ten years.

Experts have warned that unless the Government acts now, an entire generation faces an old age blighted by heart disease, cancer, diabetes and other diseases brought on by obesity.