Feast & Famine: The Alternate Day Diet

It wasn't that long ago that we braved bad breath and high blood pressure on the Atkins, ignoring health warnings – and common sense – in our desperation to shed pounds. Recently, however, it has looked like the days of dangerous fad diets were over, replaced by a healthier, more sustainable attitude to weight loss. Sadly the growing buzz around a new eating plan suggests otherwise.

Dubbed "part-time anorexia" for the drastic eating pattern of bingeing and starving that it recommends, the Alternate Day Diet is the brainchild of plastic surgeon James B Johnson. Criticised by health professionals as physically and mentally damaging, the diet encourages followers to eat "whatever they want" every other day, but virtually nothing the next.

The idea of a diet in which absolutely no food is off limits is understandably seductive, particularly for those long-term dieters that have spent years ignoring the bread basket and turning down pudding. The gruelling diet days – also known as "down days" – are less appealing. On these days, followers must limit themselves to a meagre 300 to 500 calories. Given that the average woman needs 2,000 calories a day, and the average man 2,500, this seems woefully inadequate.

During the first few weeks of the diet, Dr Johnson advises dieters to consume their down-day calories in the form of protein shakes, to be sipped throughout the day.

Anna Denney, a nutrition scientist at the British Nutrition Foundation, says: "You will definitely feel the physical effects if you only eat 300 calories in a day – you'll probably feel hungry, sick and dizzy. Psychologically it is going to be challenging too – one day you are telling people to have no self-control, the next they have to have a will of iron."

So, imagine stuffing yourself with biscuits, chips, steak, wine, chocolate... every forbidden food, and then "balancing" it out by fasting the next day. If you think that this sounds more like an eating disorder than a diet plan, you are not alone. Dr Johnson's diet has already captured the attention of pro-anorexia websites and – even more worryingly – teen internet message boards, on which girls as young as 12 swap health and beauty tips.

There are notable parallels between the Alternate Day Diet and bulimia – a condition that has affected many influential celebrities, including Britney Spears and Geri Halliwell, in which sufferers deprive themselves of food, and then overeat to compensate – and experts have expressed concerns that the diet may encourage unhealthy eating patterns.

"A disordered eating pattern such as this is obviously not to be recommended," says Mary George of the eating disorder charity Beat. "Depriving the body of regular nutrients in this way over a period of time could lead to long-term harm and possibly take someone down the path to a full-blown eating disorder."

Instances of eating disorders in the UK have more than doubled since the 1960s, with binge-and-purge eating patterns becoming more and more common. An estimated 3 per cent of females in Britain between the ages of 10 and 20 suffer from problemsrelated to a binge-and-purge diet.

While it must be remembered that eating disorders are a mental illness, not just "a diet gone wrong", health professionals believe that countless people are engaged in a less severe, but still extremely damaging, cycle of "binge and starve" eating. This cycle often begins when an individual attempts to restrict their food intake order to lose weight, but then "breaks" their diet and overeats due to feelings of deprivation and hunger.

Dr Graham McGregor, professor of cardiovascular medicine at St George's Hospital, London, says: "We did studies on medical students in which we saw that people who fasted would get so hungry that they'd then binge on the worst possible foods. It is a see-saw effect. You also get lots of salt one day and very little the next, which has a dramatic effect on the body. It is a totally unphysiological thing to do."

Despite the stresses that such extreme eating patterns place on the human body – overloading the digestive system, raising blood pressure and causing dehydration – Dr McGregor believes that this is now extremely widespread.

"Most women starve and binge to an extent," he says. "They want to lose weight, so they eat very little, then they get really hungry and when their boyfriend takes them out to dinner, they eat a huge meal."

While Dr Johnson, who is based in New Orleans, admits that extreme diets can trigger or exacerbate eating disorders, he denies that his new diet encourages this sort of unhealthy behaviour. He insists that the small amounts of food allowed on down days are enough to prevent dieters experiencing the extreme hunger that could lead to gorging on up days.

"I haven't seen anybody on this diet who goes to extremes and binges or starves," says Dr Johnson. "I don't recommend going without food completely, because if you starve all day then that can trigger a loss of control and you'll be non-stop eating." He believes that the diet actually regulates the appetite, meaning that if people have eaten lots one day, they will be less hungry the next.

Denney disagrees. "Eating lots one day and little the next doesn't teach people the importance of balance in their diet," she argues. "Young people in particular need to learn to regulate what they eat, and a day of gluttony followed by a day of starvation won't help them to do this."

Dr Johnson's book claims that the roller-coaster calorie consumption of alternate day eating is not only easy to follow, but also triggers physical effects that help followers to lose weight. While most low-calorie diets slow down the metabolism, reducing the rate at which the body burns calories and thus hindering weight loss, Dr Johnson insists that his diet works to speed up the metabolism, tricking the body into burning up more calories than before.

"There was a study at the Pennington Biomedical Research Institute where volunteers ate nothing at all every other day for three weeks. They lost 2 per cent of their body weight over that time, but their resting energy expenditure didn't change. The alternating days system prevented the metabolic rate from dropping."

The idea for the diet came about after Dr Johnson, who had struggled with his own weight, spotted a scientific study in the American Journal of Clinical Nutrition which suggested that mice that were fed only every other day experienced significant weight loss and other health benefits.

"When I read it, it struck me like a thunderbolt," says Dr Johnson. "It just made sense. Personally, I knew that I couldn't do 'not eating anything' on alternate days, but I could cope with consuming about 20 per cent of my normal daily intake."

In the clinical trials Dr Johnson conducted in 2004, he said that volunteers lost on average 8 per cent of their body weight over an 8-week period, and experienced other health benefits.

"I was sure that the diet had benefits other than losing weight, so I picked some asthma sufferers to take part in the trial," adds Dr Johnson. "They showed dramatic improvements in their peak flow (how fast you can blow air in and out of your lungs). There is a clear biological hypothesis for this – the very low calorie intake on the down day triggers an anti-inflammatory gene, which improves the asthma."

Johnson believes that his diet can also help to lower blood pressure and improve conditions such as arthritis, as well as reducing levels of potentially harmful free radicals in the bloodstream – claims that have already met with some scepticism.

"I'm unaware of any evidence that supports this hypothesis," insists Dr McGregor. "I mean, what happened to the Atkins? People who try diets like this might lose weight at first – because they are watching what they are eating – but they'll put it back on again."

While doctors may be right to question such a radical diet, Dr Johnson's plan does seem to have tapped into something. Internet message boards are heaving with glowing testimonials from thousands of people already subscribing to the schizophrenic eating patterns. Oddly, perhaps it is precisely because it is so extreme that Dr Johnson's "feast and famine" approach appeals to the dieters of 2008 – in a culture of size zeros and rising obesity levels, it doesn't seem all that crazy.

Day by day: the diet

I'm not desperate to lose weight, but with summer on the way, the thought of baring arms, legs or anything in between is enough to make me wish that the needle on the scales hovered a few lines lower. I decide to start on an "up" day, meaning that I can eat anything I want. Turns out, I want a lot of food, most of it fattening.

My usual breakfast of porridge or toast is eschewed in favour of a cinnamon roll and two pains au chocolat, sushi lunch swapped for a giant panini and crisps, and modest dinner replaced with an Indian banquet, followed by a box of chocolates. I could get used to this diet.

I wake up the next day nursing a "food hangover", complete with dry mouth, gurgling stomach and slightly sick feeling. If this continues, avoiding food should be a doddle.

Needless to say, it doesn't last. At 10.30am I can smell toast, and it's a damn sight more appealing then the strawberry meal-replacement shake Dr Johnson recommends I "sip throughout the day". By 4pm, I'm grumpy, tired, shaky, and more than a little hungry.

I'm allowed a meal in the evening, as long as it is less than 250 calories, and leaf through Dr Johnson's recipes in search of something edible. No such luck. I settle for a broccoli omelette, which wouldn't fill the gap in a hollow tooth. I sneak in a cracker with jam before bed, which sends me over my calorie limit. This is nowhere near as fun as yesterday.

The cycle continues for the rest of the week – I feel too full one day, and too hungry the next. When I finally step on the scales, I find I have lost 2lbs. I'm pleasantly surprised, but I won't be sticking with it. Dr Johnson is right about one thing – it doesn't feel like a diet. Shame it doesn't feel great either.