Warning: This article tells you a starvation diet could actually be good for you - and make you live longer

Warning: This article tells you a starvation diet could actually be good for you - and make you live longer

By VICTORIA FLETCHER

Published: 21:23 GMT, 4 August 2012 | Updated: 21:23 GMT, 4 August 2012

'Slim as a pin': Victoria with her 78-year-old mother Shirley

Pinned to my mother Shirley’s fridge on yellowing, curled paper is a handwritten copy of a two-week crash diet. It has been there since 1979, the year she decided she wanted to shed a stone in a fortnight. Its survival is testament to the faith she holds in it.

Among other tortures while on the diet, she allows herself no more than half a grapefruit and a slice of dry toast with black coffee each morning. Lunch is a few cold cuts of meat and a side of vegetables, and dinner is similar. On a typical day this will amount to about 650 calories.

Now 78, you would have thought she’d have deserted this gruelling regime and allowed herself to go into diet retirement.

But like so many women of her generation, she believes the occasional fortnight of eating little is key to a svelte figure and good health.

Such extreme slimming plans have drifted out of fashion in the past few decades. Crash diets are supposed to slow your metabolism down, leading to more weight gain when you stop.

These days, the mantra recited by the medical profession is steady weight loss rather than starvation. And being curvy – a la Mad Men’s Christina Hendricks – is in vogue.

But it may be time to reconsider this approach. And my mother, with her maddening crash diet, might be on to something. Tomorrow, a BBC TV Horizon investigation looks into the health benefits of fasting.

Science reporter Michael Mosley speaks to scientists who have discovered that periods of eating very little or nothing may be the key to controlling chemicals produced by the body linked to the development of disease and the ageing process. This backs up  recent studies on animals fed very low-calorie diets which found the thinnest (without being medically underweight or malnourished) are the healthiest and live the longest.

The key, say researchers at the University of Southern California’s Longevity Institute, is the hormone Insulin-Like Growth Factor 1 (IGF-1). Mosley explains: ‘IGF-1 and other growth factors keep our cells constantly active. It’s like driving with your foot on the accelerator pedal, which is fine when your body is shiny and new, but keep doing this all the time and it will break down.’

According to Professor Valter Longo, director of the Longevity Institute, one way to take the foot off the accelerator, and reduce IGF-1 levels dramatically – as well as cholesterol, and blood pressure – is by fasting.

Controversial theory: The reason experts haven¿t emphasised this is that they don¿t want to trigger eating disorders or demotivate the overweight trying to get into the healthy weight range

‘You need adequate levels of IGF-1 and other growth factors when you are growing, but high levels later in life appear to lead to accelerated ageing,’ he says. ‘The evidence comes from animals such as the Laron mice we have bred which have been genetically engineered so they don’t respond to IGF-1. They are small  but extraordinarily long-lived.’

The average mouse has a life span of two years – but the Laron typically live 40 per cent longer. The oldest has lived to the human equivalent of 160. They are immune to heart disease and cancer and when they die, as Prof Longo puts it: ‘They simply drop dead.’

During the film, Mosley tries various fasts – for three days straight, and for two days a week, for six weeks – with dramatic results. Not only does he lose weight, but his cholesterol levels and blood pressure improve. These findings chime with recent reports that reaching a ‘healthy’ Body Mass Index (BMI) may not be enough – we need to be as slim as possible to reduce our risk of illness.

The reason experts haven’t emphasised this is that they don’t want to trigger eating disorders or demotivate the overweight trying to get into the healthy weight range. There is only so long, however, we can shy away from this because the evidence keeps mounting.

So has my mother’s generation been right all along? Is striving to be ‘slim as a pin’ good for us? And does this mean those who slip into our size 12 jeans believing we are healthy are fooling ourselves?

Matthew Piper, of the Institute of Healthy Ageing, University College London, says: ‘Studies on monkeys show if we restrict the diet there is a delay in the onset of cancer, coronary heart disease and diabetes in later life as well as staving off dementia.’

Reducing our food intake over months or years could boost lifespan by 15 to 30 per cent, experts believe. 

My mother says her determination to stay slender comes from her childhood during the war. ‘We were on rations until 1954, so everyone was slim. Now food is everywhere,’ she says, repeating to me two phrases she learnt from her mother – ‘He who sleeps, eats’ and ‘You have to suffer to be beautiful’.

Striving to be a normal weight is not enough. We need to get slim

I used to ignore this rather harsh advice, but my mother has been in good health her whole life. And now there is the science behind her arguments. I am a 36-year-old mum of two and haven’t gone on a diet for years. I try to have my five-a-day but allow myself wine, cheese, chocolate and cake.

I exercise when I can but getting thinner has never crossed my mind as I have a BMI of 23, and I am a size 12. But if I look through the studies, having a size 12 figure means I am not in the fabulous shape I had arrogantly assumed. I need to lose a staggering 10lb to achieve a ‘healthier’ BMI of 19.5.

And so I decide to give my mother’s diet, called the Scarsdale Medical Diet, a shot (see box, far left).

Although it was a hit for the Seventies audience relatively new to slimming, it is brutal physically and mentally. But Dr Rachel Thompson, of the World Cancer Research Fund, says: ‘Whatever your BMI, if it goes up so does your cancer risk. It’s better to be at the lower end of the healthy BMI range if possible.’

For every two points you jump up the scale, your risk of postmenopausal breast cancer goes up three per cent. I don’t think I’d recommend the Scarsdale to a friend as it is too extreme and makes you obsess about food in a way that cannot be good for mental health. But it’s taught me I can lose extra pounds by waiting until I am really hungry before eating and that I should stop having snacks between meals.

Perhaps the most important thing about that yellowing paper on mum’s fridge is what it represents about her generation. They knew something scientists are only beginning to find out. It’s an unpalatable truth for our curvy generation but striving to be a normal weight is not enough. We need to get slim.

Horizon: Eat, Fast And Live Longer, BBC2, tomorrow at 9pm.

'It's been hell but I'm skinny and 8lb lighter'

Strict limits: The Scarsdale Diet is a high-protein, low-carbohydrate mix

The Scarsdale Diet is a high-protein, low-carbohydrate mix with a fixation on grapefruit. 

Unlike other high-protein diets that allow you to stuff yourself with fatty bacon and cheese, this diet imposes strict limits.

Breakfast is always half a grapefruit and a piece of toast with no butter or jam. Lunch on day one is cold cuts of meat with all fat removed and a tomato.

Supper is fish with salad and a piece of bread followed by more grapefruit. You must also drink lots of water and, thankfully, black tea and coffee are allowed.

The first days are a blur of dry toast, fruit and sliced tomatoes and meat. I don’t feel hungry, having eaten a large curry the night before I start, but I miss sugar and its energy boost.

By Wednesday I am ravenous. No sooner do I eat the allotted meal of half a tin of tuna with a squeeze of lemon followed by another grapefruit than I start to think about the next meal. And two hours before this is due, I feel hungry.

By the end of the week I am grumpy, obsessive about food and feel shattered. I have lost 4lb, my stomach is flatter and I feel ‘empty’ although my thighs look distressingly similar to a week ago.

By week two I still feel very tired but the weight is falling  off by a pound a day. My idea of feeling full is also changing.

After a meal, I don’t feel stuffed as I used to but just not hungry any more. I have lost 8lb now, feel lighter on my feet and notice my hip bones have reappeared.

By the end of the week I weigh 9st 2lb.

It’s been hell but I know what it feels like to have a healthy BMI of 19.5. It feels really skinny. But according to the experts, if I keep the weight off, I will have done myself no end of good.

Fasting diet lowered my blood pressure and cholesterol

By Michael Mosley BBC HORIZON REPORTER

Converted: Michael Mosley believes fasting can 'extend my healthy years' and is sticking with the regime

I’ve spent the past few months trying out a diet for the BBC’s science series Horizon. It’s said to help you lose weight, improve your biochemical health markers and, possibly, slow down ageing. The results have been spectacular.

You can eat pretty much what you want, but the catch is that you have to go through periods of fasting.

I’ve always followed medical advice: never crash diet. But after speaking to Professor Valter Longo, who has been studying the health benefits of fasting, I agreed to try it.

I fasted for just over three days. I ate nothing at all for 82 hours, but drank plenty of water and black tea, plus one cup of low-calorie soup a day. It wasn’t much fun, but I didn’t get any headaches, I slept fine and I felt energetic throughout.

At the end, I had missed out on about 7,500 calories worth of meals. Since you need to cut your food intake by about 3,500 calories to lose 1lb of fat, that means I’d lost just over 2lb of flab.

I also had my blood tested and my levels of the hormone IGF-1 – which scientists believe is linked to ageing – were significantly lower than before.

This, says Valter, is the key to how fasting helps prolong lifespan. The lower our IGF-1, the less likely we are to develop a host of diseases.

The problem was I couldn’t see myself doing three-day fasts regularly, so I tried out something less extreme. I met Dr Krista Varady, of the University of Illinois, Chicago. She explained the merits of Alternate Day Fasting (ADF).

One day you eat whatever you want, the next day you fast. Even on my fasting days I would be allowed about 600 calories.

She said: ‘We recently finished a trial that looked at two different groups, about 16 people in each, doing ADF for ten weeks. We put one group on a low-fat diet, eating lean meats fruits and vegetables. The other group were eating lasagne and pizza. Both groups lost weight but the people eating high-fat meals lost the same amount of weight as those eating low-fat meals.’

And it wasn’t just weight loss. Both groups saw similar falls in the ‘bad’ cholesterol, LDL, and in blood pressure.

I gave it a go, but found it too hard and ended up doing a 600-calorie fast one or two days a week.

I started out at 13½ st. After six weeks on my new regime, I have lost 20lb. My cholesterol, blood glucose and IGF-1 have all improved markedly.

I do believe that with intermittent fasting I can slow down my cells and extend my healthy years. So I plan to stick with it.

I’ll let you know next year if I succeed.