“The types of carbohydrate we eat in the UK have changed profoundly,” he says. “In the 1950s and 1960s, carbs would have largely been potato, bread and cereal with some soft drinks, cake and biscuits, though these were limited by expense. Now, consumption of concealed sugar in low-cost processed and fast foods is considerable, and refined carbs in low-cost pies, pasties, bakery goods, plus sugar in soft drinks has risen enormously.”

There is, he adds wryly, “always a queue outside the local Greggs – even though a new bakery has opened next door and has its own queue”. But what about NHS guidelines that suggest we should get 50 per cent of our calories from carbs? Prof Taylor says, “Worthy food experts suggest that we should all be eating vastly more carbs. They mean the high-fibre, unprocessed, sugar-free types, but Brits hear this message and pile on potatoes, rice, pasta, pastry and sugary foods. These easy-to-eat refined carbs encourage overconsumption.”

Kim Pearson is a London-based nutritionist whose clinic specialises in weight loss. “We put a lot of clients on lower-carb diets,” she says. “Why? Because they are very effective. Many people who struggle with their weight eat a diet based on refined starchy carbohydrates and ultra-processed foods. They are low in nutrients and cause blood sugar dysregulation, with big dips and peaks. This causes cravings, hunger pangs and constant snacking.”

A high-carb diet can become more of a problem as we get older. Dr Sarah Berry is an associate professor in nutritional sciences at King’s College London and lead nutritional scientist at the health science company Zoe. Her research on 1,002 women, published in The Lancet, looks at the way that the menopause changes the way carbohydrates are handled by the body.

Carbohydrates break down to glucose in the blood, which in normal healthy people triggers the release of the hormone insulin so that the glucose from food can enter the body’s cells. From here, the cells can use the glucose for energy.

On average, the Predict study found that post-menopausal women had worse blood sugar markers like fasting glucose, insulin and greater insulin insensitivity, a sign of a higher risk of pre-diabetes. In someone with diabetes, glucose remains in the bloodstream at higher levels than in people without diabetes.

But that doesn’t mean it’s necessarily healthy to adopt an extreme keto diet, which is high in animal fats and proteins and low in fibre. This month, a new study, presented at the American College of Cardiology’s annual meeting, suggested that adopting an extremely low-carb keto diet could raise cholesterol levels and more than double the risk of heart attacks and strokes. A keto diet was considered one with 45 per cent of total daily calories coming from fat and 25 per cent from carbohydrates.

On the other hand, a recent study published in Diabetes Care found that following a low-carbohydrate diet may cut death rates from heart disease and cancer in people with Type 2 diabetes.