On their website, Diabetes UK counsels “there is no such thing as a ‘diabetic diet’ or food plan” (Check diabetes risk, Letters, May 31). This is broadly true as we all have individual tastes in food. However, sugar is one substance that is added to almost every manufactured food product, from bread to preserved meat to sauces and dressings. Unlike normal food, which must be digested to release its potential energy, sugar contains nothing of nutritional value; it is manufactured, refined and added to food because it is tasty and a source of instant energy. Absorbed initially in the mouth, sugar is also attractive to the gut biome, part of our immune system, without which we could not digest normal food. Indeed, the biome - bacteria, viruses, yeasts and fungi that populate the gut - can alter its balance to favour organisms that love sugar. People who say they have a ‘sweet tooth’ are admitting that they have permitted their population of gut-organisms to shift over to those that are sugar-dependent. But eliminating sugar can shift the balance back. Unfortunately, antibiotics kill protective gut-bacteria as well as infectious ones. Over-prescription of antibiotics impairs digestion, creates sugar-dependency and reduces immunity to further infection. Sugar - unlike fat and salt - is addictive. It has been found to be more addictive than cocaine. Adding sugar to food simply bypasses the body’s sophisticated digestive processes and compromises efficiency.

The medical profession, nutritionists, government, the food industry, and the media are still actively promoting the outdated, scientifically disproven idea that all calories are created equal. The well-worn notion that as long as you burn more calories than you consume you will lose weight is simply wrong. The calories in refined carbohydrate foods like sugar, instantly available as energy, lead to blood-sugar and insulin spikes. Complex foods of equal calorific value require slow and thorough digestion and encourage the spread of a wide variety of gut organisms. Ancel Keys was the American physiologist who hypothesised that dietary saturated fat causes cardiovascular heart disease and should be avoided. As a result, in 1956, the American government and the American Heart Association claimed that a diet which included large amounts of butter, lard, eggs and beef would lead to coronary heart disease. Keys’ work prompted an explosion in the high-sugar, refined-carbohydrate, cereals industry. Ever since, despite evidence to the contrary, fat has been linked causally to the diseases of modern life while sugar has become a cultural staple. In 1972, John Yudkin published, ‘Pure, White and Deadly’ to summarise the evidence that over-consumption of sugar was leading to a greatly increased incidence of coronary thrombosis, stroke, dental caries, obesity, diabetes, liver disease and possibly also gout, dyspepsia and some cancers.

Government subsidies for the farming of sugar beet have made sugar cheap and ubiquitous. When governments see themselves as utopians with the authority to dictate to the medical profession, pharmaceutical industries, food manufacturers and farmers, they create a dependent client-state, punish innovators and betray the citizens who elect them.

I would like to offer a £1,000 prize to an inventor who can design a device that can ‘read’ the ingredients off manufactured food labels, identify added sugars and beep or flash a light if there aren’t any. It cannot be an ‘app’. It must be a ‘probe’ that can easily riffle through packaging. It is surprising to find so-called healthy/organic products, including those that claim to help weight reduction, to be high in sugars. Suggestions can be forwarded to me through this newspaper.

Prof. Christine Wheeler McNulty

Oxhey Hall, Oxhey