Anton La Guardia and his family get out the blender to get a taste of life on a raw food diet

I couldn't help myself. The aroma suffused the air, my mouth was moist at the thought of the morsels melting on the palate, and my stomach stirred in agreement. Looking over my shoulder to make sure the children could not see me, I walked up to the counter, ordered a cheeseburger and ate it behind the cover of a potted plant in the service station. Delicious.

My wife, children and I were about to try the latest diet craze, "raw food", in which one is supposed to forsake all cooked food - never mind junk.

For the next two days, at a raw food retreat in Norfolk, we crunched salad until our jaws were sore, savoured nut paté, and drank chocolate drinks made from almond milk and raw cocoa.

I never knew my children could pull so many contorted faces. Our two-year-old spat out his date and nut breakfast cereal. When my youngest daughter was made to taste salad with sprouted mustard seeds, she gurned with disgust. Still, some offerings, like raw tomato "crisps", went down a treat.

Forget traditional calorie-counting, or the GI's glycaemic league table. Raw food is the ultimate diet and is as simple as it is extreme: just eat everything raw. Food can be dried, minced, ground, soaked, sprouted, blended, fermented, juiced - anything, as long as it is not been heated above 118°F degrees. And, you can eat as much as you want.

Actresses such as Uma Thurman, Demi Moore and Natalie Portman are said to be among those who have embraced the fad, which started in North America, then moved here. London's first raw food restaurant opened recently.

Raw food cookbooks - sorry, "food preparation" books - are multiplying. One that landed on my desk is The Raw Food Gourmet by Gabrielle Chavez. Like many raw food kitchen gurus, she shows great enterprise in mimicking cooked dishes in raw form.

Recipes include granola made with raw oats and agave nectar, courgette tagliatelle and even a raw version of shepherd's pie. There are, inevitably, salads and raw soups galore. Love crisps and snack food? No problem. Make your own raw curried flax crackers and chilli pistachios.

Fan of the raw food fad: Natalie Portman

The raw chef won't be needing his oven, but to become a true gourmet he will still need special equipment. Instead of softening food by boiling or grilling, it needs to be chewed for you by an industrial strength blender or a powerful juicer. Instead of the oven, there is a "dehydrator" - which gently dries food, rather than baking it.

The advocates of all things raw argue that cooking robs food of nutrients and, above all, kills the enzymes - the chemical catalysts that are needed to break down the food into more digestible molecules. The more extreme maintain that all cooked food is, in fact, "toxic".

In listing the benefits of going 100 per cent raw, Chavez claims that on a raw food diet, "cancer, heart disease and many other life threatening conditions can either be prevented or cured". What's more, raw living puts you "at peace with your own body... and with the animal kingdom".

There is, certainly, mounting evidence of the damage caused by overcooking and overprocessing food. Yet the raw food gospel is not entirely accepted by mainstream nutritionists who argue that while we should all eat more fresh fruit and vegetables, certain foods should be cooked to maximise their nutritional value.

In theory, raw meat and fish could be included in a raw food diet, but in practice most raw foodists are strict vegans. "Why eat a cow?" says Shazzie, a raw food goddess and our host in Norfolk. "Eat what the cow eats and you will get the nutrients without the fear that has been rammed down its throat." She advocated a "rainbow diet", in which one eats food of every colour.

Although raw foodists see their diet as a return to the "natural" way of eating, they require the benefits of globalisation - particularly in winter - to bring an ever more exotic variety of food to their plate to ensure they find the full range of nutrients.

Shazzie raves about goji berries, maca powder, raw cocoa, agave syrup, aloe nectar, seaweed and the favourite raw foodist "superfood", juiced wheatgrass - but try finding that lot at your local farmers' market.

The date and nut muesli was not much of a success with the younger set

Getting enough vitamin B12 and essential fatty acids - the "brain food" found mainly in oily fish - is a problem for vegan raw foodists. An even greater difficulty is eating enough calories, and one study found that raw foodists suffer from greater tooth erosion.

But what I really wanted to know was, is it possible to be a raw foodist in the real world? Back at home, with the help of a juicer, we made better use of all the bits of vegetable that usually get thrown away. Supermarket trips are quicker when you can ignore two thirds of the shelves, but we had to make constant sorties to expensive, specialist health food stores.

And you quickly discover that being raw-food only is as isolating as suddenly becoming kosher. You cannot touch most of the food that anybody else serves you - restaurants, social occasions and work lunches become impossible.

Some raw foodists go around with an avocado in their pocket to fill up a side salad, often the only thing you can order in a restaurant, but you are hardly going to do that at a business meeting.

So our raw food experiment collapsed almost before it had started. With the long summer evenings here, the meat has gone back on the barbecue. Hamburgers are on the menu again, too, but are these days accompanied by more raw food.

Our hybrid cooked pasta with raw tomato sauces is a hit with the whole family. Our raw Thai soup bursts with flavour. But our favourite? A raw fruit tart, with a base of crushed almonds, a "custard" of blended apples and strawberries, topped with raspberries and cocoa chips - raw, of course.

How raw works
By Chloe Rhodes

The human body naturally produces its own enzymes which digest protein, carbohydrates, sugars, and fats. Enzymes in raw foods start digestion in the mouth and are thought to aid the body's digestive enzymes, though some scientists believe that they may be denatured by acid in the stomach.

Food enzymes are destroyed by temperatures of over 118F, so the only form of cooking allowed in a raw-food diet is dehydration, which blows warm air through the food.

Raw foodists believe that cooked foods place too great a strain on the body's digestive system, and lack the vitamins and minerals provided by raw food. Some also claim that eating cooked food allows partially digested fats, proteins and carbohydrates to clog up the gut and the arteries.

The health benefits of a raw-food diet include increased energy levels, better skin, improved digestion and weight loss. A well-planned raw-food diet is full of nutrients and fibre, and low in sodium and saturated fats, all of which help reduce the risks of heart disease and some cancers.

Despite these advantages, many nutritionists are cautious about wholly raw diets. Brigid McKevith, senior nutrition scientist at the British Nutrition Foundation, says: "Although a raw-food diet is likely to be rich in fruits and vegetables, it could lead to problems in the long-term because you are limiting the types of foods that you can eat. It could be low in protein, iron, zinc and calcium as you could not eat meat or cereals."

Source: http://www.telegraph.co.uk/health/