Do you want fat with that?
For three months, Alok Jha has been testing the health claims of the controversial Atkins diet. Find out here what happened when he cut the carbs
Alok Jha
Thursday June 24, 2004
The Guardian
The Mexican restaurant in downtown Dallas was the low point. Wandering the streets for more than an hour, I had peered into countless restaurant windows to find a menu that would meet my exacting needs, and ended up on the verge of starvation at the noisy cantina. Quickly ordering, I struggled to ignore a growling stomach while waiting for the food. Then disaster struck.
A waitress rushed up and set down a bowl of freshly-made tortilla chips. The smell was intoxicating and, as if with a life of its own, my hand reached out. In slow motion, chip moved towards mouth and stomach growled approval. But this was all wrong. Dropping the chip just milliseconds from my mouth, I reached for the bitter black coffee at the edge of the table.
A close escape. For the past three months, I have been on Dr Robert Atkins' infamous diet. Like millions before me, I have given up the majority of carbohydrates and made friends with full-fat mayonnaise, steaks and copious amounts of spinach. I threw out all fruit, bread, pasta, potatoes and rice, avoided the cakes and biscuits at the local supermarket and slowly forgot the taste of a pint of beer.
The Atkins diet has become a western phenomenon while igniting the most highly-charged nutritional controversy in history. The death of Atkins at 18 stone last April hasn't stemmed the flow. More than 30 million people are reported to have followed his advice at some stage and bread and potato sales have suffered, prompting a fightback: this week bakers launched the Vitality diet, which extols bread.
Meanwhile, Atkins Nutritionals continues to tout the many scientific studies that, it says, prove the success of its diet. And these keep coming - two months ago, researchers at Duke University published evidence that low carb may be more beneficial than traditionalists once thought.
We wanted to find out what happens when someone goes on the diet, scientifically. We wanted to test the claims made in Atkins' book that not only would this counter-intuitive diet make me lose weight, it would make me more energetic, satisfied and, crucially, healthier. The experiment saw biological chemists monitoring the trace molecules in my blood; dietitians calculating exactly how much of what had been eaten; and a psychologist measuring how my mood changed.
The standard high-carbohydrate, low-fat diet advice was introduced because of research published by professor Philip James of the Rowett Institute in Aberdeen in 1983. His work was based on an epidemiological study done in the Far East where people on high-carb, low-fat diets seemed to be living very healthily.
Scientific thinking behind nutrition was challenged by Atkins, a New York cardiologist. He turned it on its head when he published details of his diet more than 25 years ago. Fat, he argued, was not the enemy. What was making people ever bigger around the waist was not consumption of butter, cream or fatty meats but over-consumption of refined flour, sugar and potatoes. Carbohydrates were making us fat.
Atkins justified his idea with a compelling account of what happens in the body when people eat too many carbs. As levels of carbs (broken down into glucose in the bloodstream) rise, so does insulin. Insulin peaks cause sugar to be stored in the body as fat: Atkins even called insulin the "fattening hormone". Cutting carbs means that there are no surges in insulin, so avoiding the production of more fat.
Atkins also claimed that eating more proteins forces the kidneys to work harder to get rid of them and that this uses a lot of calories.
Critics were quick to point out that the Atkins diet seemed to be a recipe for heart disease. Eating a lot of fat (Atkins even says in his book that a low-fat version of his diet will not work) could not be a good thing.
Others said the diet was just a clever way of cutting calories. Textbooks tell us that carbohydrates are meant to make up around half our daily calorific intake. Take that out and you have a problem - how on Earth do you replace it? On average, a man needs 1,250 calories of carbs a day. If you want to replace that with, say, sirloin steaks, you need six quarter-pounders to make up the loss - a daily gorging found only on Japanese game shows.
Another way that Atkins eases calorie-restriction is to make eating inconvenient. There are virtually no snack foods on this diet, and a few weeks after starting, a handful of nuts a day or some strawberries or raspberries can be included. No crisps, chocolate bars or flapjacks in the middle of the afternoon.
What happened when I tried to live this way? New regime; new lifestyle. First, I bought more fresh foods from supermarkets - anything vaguely pre-prepared such as ready meals is usually sugar-loaded and so disallowed - and began to invent Atkins-friendly recipes. My kitchen has never seen so much action: unused Tupperware boxes were dusted off to store the masses of food I was suddenly cooking.
Monotony was a problem. I knew that I could eat as many chicken breasts, lamb steaks and pork chops as I wanted. But after a few days the novelty wore off and I stuck to normal portions.
"Most diets create preoccupation with food and subsequent overeating because they generate a sense of denial," says Jane Ogden, a psychologist at King's College London. "The foods being avoided in most diets are the foods people like to eat and the foods at the core of any meal." So we would probably crave cream cakes and pastries but wouldn't be so bothered about the core things Atkins denies - rice or pasta, for example.
So far, so healthy. But what about all that fat that suddenly has to be eaten? The calories I was getting from fat certainly increased during the experiment, and saturated fat made up a great part of the increase.
In his book, Atkins puts no limit on fat. But earlier this year, the Atkins company was in trouble for apparently changing its advice and saying that its diet should contain no more than 25% saturated fat - a far cry from the unlimited butter, cream and oils that devotees were apparently allowed to gorge on. But Atkins Nutritional quickly countered that none of their advice had changed and that proper Atkins dieters would tend to eat only 25% saturated fat.
Whatever the answer, the Atkins diet is not a licence to eat as much fat as you want. Cheese and cream are both restricted to around 100g and three tablespoons a day, and Atkins advises against eating any trans or hydrogenated fats (such as margarine or fats in many pre-prepared foods). And the caveat is that this increased fat intake is only all right as long as you cut carbs at the same time.
Some of Atkins's positive health claims are less credible. He reckons that people following his low-carb regime will see positive effects on their cholesterol, for example. The LDL (the bad type), he says, should decrease and HDL (the good type) should increase. Having more of the bad than the good kind increases the risk of heart disease.
Six weeks into the experiment for me saw the opposite effect to what Atkins predicted - my ratio of LDL shot up compared to my HDL cholesterol. My risk of heart disease had increased.
Catherine Collins, a clinical dietitian at St George's Hospital in London, explains that my rise in LDL cholesterol is entirely predictable from the usual dietetic models. "Your body was being saturated with an amount of fat you really couldn't process," she tells me.
Cholesterol is produced from the fats we eat because the body can't absorb them in their natural state.
"The LDL is the unprocessed cholesterol. The liver will selectively try to utilise that LDL and decide what to do with it - whether to make HDL cholesterol or offload some of it into things like triglycerides," explains Collins.
When I started the diet, my fat intake jumped and my liver struggled to cope. "Something like a load of lorries trying to enter a supermarket loading bay," Collins says. "Your liver was being overwhelmed by the fact that it couldn't process it quickly enough to convert it into HDL or store it."
Sarah Brewer, a doctor and adviser to Atkins Nutritionals UK, says there is no scientific evidence that the Atkins diet has a significant negative effect on LDL cholesterol. "LDL can either go up, down or stay the same for the first two months," she says. "If it goes up, it tends to go down after two months. It's a short-term effect."
Jeremy Nicholson, a professor of biological chemistry who heads a world-leading metabolic research team at Imperial College London, says the results show the problems in prescribing one way of eating to a large and varied population. "Even if what Atkins says is true about improvements in cholesterol, for you, it went the opposite way to what is regarded as healthy," he told me.
This does not prove Atkins' assertion is wrong outright, but outlines the fact that individuals react differently. Nicholson says the Atkins diet can be seen as an intervention to a person's metabolism, like a drug. Just like a drug, some people react differently. "In any population you'll have extremes but, for most people, Atkins will probably accelerate heart disease and could negatively impact on other organ systems: we just don't know yet," says Nicholson. "A large selection of the US and UK populations is engaged in a potentially dangerous experiment, the outcome of which we may not know epidemiologically for at least 20 years."
Current calorific intake and nutrition advice is based on population statistics. Nicholson says we need to move to more individualised advice, as researchers are trying to do in pharmacology.
Understanding diet in the future will be a case of finding the genes responsible for negative traits (such as obesity) and working out how they interact with the stresses in our individual environments. Nicholson's lab at Imperial is spearheading the effort. Two decades ago, he devel oped a technique where he could assess a person's metabolic status - the combination of genes and environment provide a unique fingerprint for an individual. This fingerprint gives Nicholson the ability to model how any intervention to metabolism, such as a drug or diet, will affect that person.
The Atkins debate will rage for some time. The latest salvo was delivered in May with the publication of research from Duke University. During a six-month comparison study, people on a low-carb, high-protein diet lost more weight than people on a low-fat, low-cholesterol and low-calorie diet. Accompanying editorials sang the praises of low-carb routines and even nutrition luminaries such as Walter Willets, professor at Harvard medical school, said it was time to start taking Atkins-style diets more seriously.
There's a long road to go. There may be many papers published for and against low-carb diets but there will be no resolution any time soon. "Just because there are published papers doesn't mean something is correct. Everyone can make mistakes," says Nicholson. "The recent Harvard publication and the fact that Willets is well respected doesn't make him Yoda.
"You need a balance of opinions from eminent experts and a broad scientific consensus based on widely gathered evidence over many years. It took almost three decades from the first epidemiological studies on smoking before the now obvious health risks were widely accepted even by doctors."
My conclusion? The weight loss was great but I felt restricted by the compromises I had to make. I learned some good lessons: it is possible to eat healthy food without too much effort and vegetables are not the enemy. But, according to the data, for the past three months I have put my health at risk by eating the Atkins way.
Watching England play in Euro 2004 last week, I sat down to my first pint of beer in more than 12 weeks. A friend brought over some crisps and, hesitantly at first, I began munching the indulgent, carb-rich junk food once again. It might have been the wrong food to celebrate the end of a long experiment - too unassuming and simple, perhaps. But it tasted great.
· Alok Jha will discuss his Atkins experiment at the Food x-change: a debate on food and the food industry, at the Dana Centre, Queen's Gate, London SW7, on Tuesday June 29 at 6.30pm. The event is free, but prior booking is essential on 020 7019 4940
Further reading
· Read Alok Jha's diary, and discuss the experiment with him
· The psychology of eating: from healthy to disordered behaviour, by Jane Ogden. pub. Blackwell, Oxford, 2003. ISBN 0631233741
· Jeremy Nicholson's company, which specialises in metabonomics
· Atkins Nutritionals UK
· Details of the Food x-change event
|
Linear Mode
