People who write popular books about diet and health are often crusaders so convinced they have discovered the secret to battling the bulge or improving health, they feel an overwhelming desire to spread the word.
By contrast, Dr Paul Clayton - author of diet-related best-sellers such as Health Defence and After Atkins and Other Low-carb diets - does not appear to be on a mission to save the overweight yet nutrient-deficient masses from themselves.
For Clayton, who coined the term 'pharmaco-nutrition' in the mid-1980s and now chairs the food and health forum at the Royal Society of Medicine, unravelling the relationship between diet and health is "an exercise in intellectual curiosity"; he didn't go to medical school to save lives, he observes: "I just wanted to study."
And it was while studying at Edinburgh University in the late 1970s, where he shared some lectures with vets, that Clayton became struck by the role nutrition played in veterinary medicine. "So I asked my professors, 'why don't we study this?' And they said, 'it's not relevant'. Even then I could see that that was completely stupid."
But there was a problem. While knowledge about the pharmacological properties of individual food derivatives was growing all the time, the results of human intervention studies exploring the merits of these derivatives were disappointing and inconclusive. There were two possible explanations, says Clayton, who has since carved out a successful career as an author, consultant and expert advisor. "Either nutrition was not a science at all, or we were asking the wrong questions. It became obvious to me that the reason so many trials had failed was because they were designed along pharmaceutical lines."
Foods, he contends, are not drugs; "you can't think in terms of single inputs. You have to look at all of the metabolic imbalances that are responsible for driving degenerative disease and cross reference those against a programme of nutrition. You are not trying to shoot patients with one magic bullet, you are providing a comprehensive support programme and giving the body all of the things it needs to mend itself."
There are many cases whereby, using this approach, degenerative disease can be stabilised or even reversed, claims Clayton, who is also a visiting fellow at Oxford Brookes University and academic director at the Trygge Helse Academy in Tonsberg, Norway.
Mainstream medicine, he says, has successfully seen off the kind of infectious diseases that killed off our grandparents' generation, but has spectacularly failed to tackle the degenerative afflictions that are killing us today, such as cancer, heart disease and type 2 diabetes, all of which are related to poor diet and lifestyle. If we can tackle these, it will be "interesting to see what will kill us in the next century", says Clayton drily.
In the meantime however, we need to find more effective means of ensuring people get the nutrients they need without consuming more energy than they are expending. "Peddling the lie that it's easy to get all the micronutrients you need when you are only eating 2,000 calories a day is ignorant and uninformed," argues Clayton. "In fact it's almost impossible to achieve unless you are incredibly disciplined." For most of us, he says, supplements or functional foods offer a far more convenient means of ensuring we get the right nutrition.
Likewise, the popular notion that popping pills instead of 'real' food means nutrients are not as effectively absorbed is also "nonsense", he says. "We know enough about the phytochemistry of plants, fruits and vegetables to be able to isolate most, if not all, of their bioactive ingredients and put them into pills."
Ill-informed, deranged and vocal
The kind of 'neo-luddism' that characterises the popular debate about food is holding back progress, he adds. "UK consumers are pretty neophobic. They are also scientifically illiterate in a way that the Japanese, who have really embraced functional foods, are not." Indeed, food scientists are regarded with such suspicion that "vocal, ill-informed and sometimes deranged people" have been allowed to hijack the health debate.
The tragedy, he says, is that unless we make radical changes to our diets, things will only get worse. "We are living in a pathogenic, never mind obesogenic, culture. Type 2 diabetes hardly existed 100 years ago. Now IGT [impaired glucose tolerance] affects one in four adults in Britain. Our environment actively makes us sick."
But is neo-luddism solely to blame for consumers' failure to wholeheartedly embrace dietary supplements and functional foods? Not entirely, concedes Clayton, who has just taken up a post as scientific director of the Szent-Györgyi Institute in Budapest, which was set up to trial pharmaco-nutritional interventions in the treatment of degenerative diseases. "A lot of supplements are designed by people who know nothing about nutrition and are designed to a price point. Likewise, many simply do not contain meaningful levels of nutrients. Without doubt, there are also a lot of quacks in the market, which has dented its credibility."
In this regard, the prospect of tighter restrictions on unsubstantiated health claims via the EU Nutrition and Health Claims Regulation can only be a good thing, he says. But an overly onerous regulatory safety regime is not helpful, says Clayton, a former senior advisor to the UK government's Committee on Safety of Medicines. "EU bureaucrats are obsessed with the precautionary approach. By demanding zero risk, however, they are putting European consumers at far greater risk because the status quo is so unhealthy."
Efficacy of course, has to be proven, and companies should not be allowed to get away with peddling unscientific nonsense, says Clayton, who claims that "95% of weight management ingredients on the market don't work"
However, new approaches to weight management are clearly needed: "There are a few very exciting ingredients." One is caralluma fimbriata - an edible succulent from the same family as hoodia gordonii, which increases satiety and reduces the formation of new fat cells, he claims.
Another is capsiate, a thermogen derived from sweet peppers. "Forget caffeine and green tea", says Clayton. "This is the real thing. By eating 500g a day, it ups your core temperature so you can burn an extra 3-400 calories a day while sitting on the couch."
While only properly controlled scientific studies light Clayton's fire, the anecdotal evidence around these ingredients is also pretty compelling, he adds. "In Hungary they have a TV show called The Biggest Loser, and a team I advised took a combination of caralluma and capsiate and won all three gold medals! One contender lost 40% of his bodyweight in five months and is now entering the Guinness Book of Records!"
While capsiate alone will not solve the obesity crisis, there is no doubt that fresh approaches are needed, says Clayton. "There is no harm in telling people to reduce their portion sizes or spending millions reformulating products by traffic lights, but we all know that doesn't work."