To diet for

Through the eye of the camera she looks like a goddess of vitality. The lean limbs and athletic poses all combine to make Geri Halliwell, former Spice Girl, an image to envy. She is rich, successful and now, above all, she is thin. After a diet and exercise regime, the 5ft 2in singer, who fronted the Spice Girls with 34E curves, has transformed herself into a six-and-a-half-stone elf. 

To many young women she has a body to die for. Unfortunately, it is possible that Halliwell might do just that since in the flesh - or what's left of it - she is no epitome of health. Instead, she appears to be in danger of what doctors call "diet damage". 

After years of seeing her weight wobble one way and another. Halliwell cut out the cream cakes and went into overdrive at the gym. Now it has emerged that she is also having vitamins injected into her bloodstream. 

"Vitamin injections are part of the course for many artists," said her publicist defensively. "She's doing 12 to 18-hour days and travelling all over the world. It's to boost her energy levels." 

Others are more skeptical, suggesting that Halliwell's dramatic loss of weight has impaired her ability to absorb vitamins from food. Too little fat in one's diet, say nutrition experts, can lead to a deficiency of essential nutrients. 

When that is made good by taking vitamin tablets, the stomach lining acts as a filter against an overdose. Intravenous injections offer no such safeguard and in excess could cause kidney damage. "In the most extreme cases it can lead to death," warned the British Nutrition Foundation. 

Halliwell hardly seems about to keel over on stage; but that sort of obsession with slimming, and the diets favoured by many other celebrities, have got health experts worried. When Which? magazine recently asked nutritionists, physical trainers and psychologist to examine 14 best-selling diet books, most of them were found wanting in sound nutritional advice. 

It is not hard to see why. Among current fads is the low carbohydrate, height protein diet popularised by Dr. Robert Atkins, who is a cardiologist, not a dietitian. 

His teachings have been made fashionable by film celebrities such as Minnie Driver and Renee Zellweger. But critics say that too much protein and not enough carbohydrate can lead to calcium leaching from the bones and excess nitrogen damaging the kidneys. It can also give you bad breath. 

Another flavour is the Blood Group Diet, which rests on the notion that different people have evolved to eat different foods. The type 'O' blood group (about 45 of the British population) first appeared when man was a hunter reliant on animal protein, goes the hypothesis. Type 'A' (43) evolved as agriculture developed and is more suited to vegetarianism. Types 'B' (9) and 'AB' (3) relate to a nomadic lifestyle as well as agriculture, and are suited to a broader range of food. 
Essential truths 

The inventor of the diet Dr. Peter D'Adamo, has claimed that it can "lead you back to the essential truths that live in every cell of your body and link you to your historical evolutionary ancestry". 

Fans, such as actress Martin McCutcheon, are happy if it merely helps them shed a few pounds. Experts are in broad agreement on the value of blood group eating habits. "It's cobblers," said one nutritionist. "There is no scientific evidence that it can be helpful at all," said another. 

If that's not your cup of green tea (which, incidentally, is supposed to guard against cancer), there is always The Zone, possibly the most popular diet of the moment, particularly in Hollywood. 

It lays down strict proportions of carbohydrates, protein and fat for every meal. This is not so much dangerous as impossibly inconvenient. What do you do when invited to dinner? Reply that you would love to accept, provided the main course is precisely 30 protein, 30 fat and 40 carbohydrate? 

Despite such difficulties, the latest edition of the Zone carries endorsements from Madonna, Janet Jackson and Arnold Schwarzenegger. More tongue-in-cheek was a book called The Skinny, which detailed the dietary secrets of successful thin New Yorkers. One was to eat alone without clothes in front of a mirror another was to lunch on nothing but chewing gum. As people gorge on these and other diets, a curious phenomenon is taking place in Britain where people are eating less but getting fatter. 

The average energy intake has been reducing for 30 years, according to Beckie Lang of the Medical Research Council Human Nutrition Research Unit in Cambridge. Yet waistlines have relentlessly expanded until half the people in Britain are now overweight. . 

There are two factors at work here. One relates to diets, the other to exercise. "The problem is that diets encourage people to cut out whole food groups," said Dr. Wendy Doyle, of the British Dietetic Association. "They don't take into account that if you cut out, say, dairy foods you are cutting out 50 of your calcium intake." The gimmicks and sudden detox diets fail to teach people how to eat a varied diet of healthy food that can be sustained without harm or resort to measures such as vitamin injections. 
Simpler approach 

Doyle advocates a simpler approach: Writing down everything you eat and drink in one week. "So many people come back saying, 'I never knew I ate all that junk'," she said. "It doesn't take a scientist to work out which foods you are eating that are pretty high in calories and probably not very high in nutrition, like the biscuits, the crisps, the cakes." Doyle also believes it is better to cut down on fattening foods rather than to try - and typically fail - to cut them out altogether. 

The other half of the equation for losing weight and keeping it lost is exercise. If you are taking in more calories than you are expending in energy, you will not lose weight or keep it off. This explains why people are getting fatter even though they are eating less: Their calorie intake has dropped, but so has the energy they expend. "It suggests that our sedentary lifestyle means we are still eating in excess of our energy needs," said Lang. Sitting in front of computers, driving cars, watching the washing machine and other domestic appliances go round: These are not activities that burn large amounts of energy. 

It has been calculated that reading a copy of Celebrity Bodies, a glossy magazine launched earlier this year that revels in the absurdities of Hollywood diets, uses up less than 20 calories. Rather than dreaming about looking like Liz Hurley, you would do better to play a game of tennis. 

Now the perils of anorexia and bulimia are joined by another disorder, according to a new book: Orthorexia nervosa. It's a condition in which people become obsessed with the quality of the food they eat. 

"These people give up their ability to live normally, subscribing to the myth that if you don't manage to follow these strict diets you are a failure," said Steven Bratman, author of Health Food Junkies. 

Science holds out some hope: Researchers have already isolated a substance in mice that suppresses appetite, raising the possibility one day of a simple pill to cure fatness. Until then there are two more straight forward solutions to faddy diets: Either run a mile from them or take them all with a pinch of salt. 

-The Sunday Times (London)