In this image-obsessed age in which 23% of the population is obese and 60% of us are on a diet at any given time, weight-loss programmes are sold like snake oil. We spend £2 billion a year on slimming aids and diet foods — and that’s before we’ve bought a single book by those over-familiar medical types who seem to have advice to spare. Dieting is almost a national pastime, with Victoria Beckham’s post-baby body and the dynamics of how she achieved it rousing almost as much debate as Lord Goldsmith’s doubts over the war in Iraq.
Into this febrile environment steps the unassuming and meticulous figure of Dr Charles Clark, who rather incongruously (or so it might seem) is an internationally regarded ophthalmic surgeon. With his soft voice and neat suit, he is neither an egomaniac surgeon or bouncing six-packed diet bore. Instead, in a world where claims and counter-claims fly around like reduced-fat custard pies, Clark’s benign cross between the Atkins’ meat feast and the GI (glycaemic index) diet sounds like a still, small voice of calm.
His latest work — like its predecessors, co-authored by his wife, Maureen — is entitled The Healthy Low GI Low Carb Diet: Nutritionally Sound, Medically Safe, No Willpower Needed. It is the first of his five works to include “GI” on the cover. Surely he’s not cashing in on the latest fad? Of course not. He explains patiently that the glycaemic index — the rate at which the body converts food into glucose — has always been central to his diet plans. Where Clark disagrees with the current GI movement is in its tendency towards tunnel vision. GI ranks foods on a scale between zero and 100. Those that have a slow-acting effect on blood sugar — pearl barley, for instance, spaghetti or noodles — give a sense of satisfaction for longer and are assigned a low GI value. Others, such as chips or jacket potatoes, have a high GI value and cause a rapid and massive rise in blood sugar, leaving you hungry within a relatively short time.
That all seems logical enough, but lard, Clark points out, is a low GI food. A diet based on lard would be ill-advised in the extreme. He sees lots of patients who have misinterpreted the GI message, eaten too much pasta and porridge and failed to get the results they wanted. “We have these things in our diet, but in moderation,” he says. “The bottom line is: how much of it makes insulin? Low GI alone is not the answer. It must be in association with a balance of food and nutrition.”
With 70 scientific papers to his name and private practices in London and Edinburgh, it seems extraordinary that Clark became a dietary guru almost by accident. The beginning of the 1990s found him working in Brisbane as a diabetic ophthalmologist. His patients, many of whom had Type 2 diabetes (formerly called adult-onset until children as young as four started to show symptoms) were not controlling the condition well.
“The advice they were following was based on the diet of 30 years ago, when people did not eat huge amounts of pasta and pizza. They ate bacon and eggs, meat and vegetables. These things don’t stimulate insulin (the hormone associated with diabetes). Insulin is only stimulated by carbohydrates, primarily refined carbohydrates.”
So Clark restricted his patients’ intake of refined carbohydrates — pasta, pizza, bread and cakes — and put them onto a regime of fish, meat and vegetables, with limited amounts of unrefined carbohydrates. Insulin and cholesterol levels dropped and the diabetic eye problems that had first brought patients into Clark’s surgery improved. In some cases, they disappeared.
His patients not only saw their symptoms — and their reflection in the mirror — improve, but by controlling their insulin and reducing their weight and cholesterol they were doing wonders for their general health and life expectancy.
Clark eagerly reels off a list: “If you have a poor cholesterol profile, you have a vastly increased risk of heart disease. Obesity causes heart disease, kidney disease, blood vessel disease, arthritis. Polycystic ovarian disease is associated with insulin resistance. Follow a low-carbohydrate diet and many of these symptoms and signs disappear.”
In these post-Atkins, diet-conscious times, none of this sounds particularly radical. At the time, it was heresy. Low-fat eating was the accepted wisdom and that’s what the Clarks did at home, until the results he saw in the clinic made him reconsider. “I’m a very, very conservative doctor and a very, very conservative research worker,” he says. “Until I went into it, I believed in the low-fat hypothesis. It made sense, but medicine doesn’t always make sense.”
His cautious soul was further reassured when the professor of cardiology at Edinburgh University “proved conclusively that the connection between cholesterol and saturated fats was very tenuous indeed when you took out the carbohydrate factor. That fitted with what we were seeing”.
It was enough to convince him that the Clark family should increase their consumption of salmon, avocados and olive oil. “We changed at home and I’m very glad. I feel much better, I’ve got much more energy, I enjoy what I think are much better foods and it’s an awful lot easier.”
Convinced that this diet could be helping many more people than those who passed through his clinics, he set about writing it all down in a measured, user-friendly way. Back in Edinburgh, working with Maureen, he produced The New High Protein Diet: How to Lose Fat the Quicker, Safer, Easier Way — and Never Go Hungry in 2002. Titles apart, this work and its successors contain no purple prose, florid claims or photographs of women in leotards. Instead, they start with theory (everything you ever wanted to know about insulin and its role in health and weight loss), move through practical examples (with nameless patients’ weight loss, body mass index, triglyceride and cholesterol levels discussed in almost clinical terms) and end up with carbohydrate-counted recipes.
Despite their measured, here-comes-the-science-bit tone, Clark’s books have been hugely successful. This is, he says, because they work. And out of all his many impressive achievements, it is the books that give him the most satisfaction.
“You are having a major effect on lots of people’s lives. It looks wonderful when you’re in newspapers in Australia for carrying out a 14-hour operation. But how much more effective would it have been if that patient had been picked up 10 years earlier in a simple screening test that cost 10p? Medicine should be about prevention. We talk about big cardiac operations . . . just think about how much better it would have been to have treated that patient by lowering their cholesterol 10 years earlier through diet.”
Aged 45, Clark is certainly a convincing advertisement for his own regime. Energetic, relaxed, slim but not skeletal, he does not look like a man who spends two days a week in London and has written five books in four years. His children, aged 11 and 14, are allowed to mix their flaked trout and beansprout salads with the normal treats of teenage life. There are limits.
And for the Clark family, the limit is white, silky and made from soya beans. Tofu, championed by just about everyone in the healthy-eating world as the only perfectly balanced non-animal source of protein, leaves them cold. “We have,” he admits, “increased our purchase of tofu while researching vegetarian recipes for this latest book. But we have not really increased our consumption. We just don’t like it.”
The Healthy Low GI Low Carb Diet is published by Vermilion on May 12, price £7.99
