Researchers at Oxford University have urged the British government to impose draconian tobacco-style sin taxes on meat, and the country’s public health authority has drafted plans to cap calorie counts on most common foods.

But British health nannies are not alone. South Africa’s health minister Aaron “Nanny” Motsoaledi also feels he has the right, and duty, to police our diet. Three years ago, he instituted a perfectly unscientific restriction on the salt content of readily available foods, based on the debunked theory that too much salt causes high blood pressure or cardiovascular disease in healthy people.

That same year, Pravin Gordhan, another nanny with a great interest in swelling tax coffers as the then-minister of finance, proposed a tax on sugar-sweetened beverages. Even according to the research the government cited, it will have a negligible effect on individual bodyweight or on public health outcomes.

Imagine, then, what the introduction of National Health Insurance will do to bolster the ambitions of nannies in government to police our diets and our lifestyles.

Private health insurance companies rely on voluntary rewards programmes to keep their clients healthy so they stay profitable to insure. They reward participation in sports and exercise, as well as choosing healthier food options in supermarkets and restaurants.

When you only have a hammer, every problem looks like a nail, however. Lawmakers (and an alarming number of academics and public busybodies) believe that these are matters to be legislated. When some people do not follow government advice, they believe everyone should have a government-approved diet and lifestyle enforced upon them via regulation or taxation. And once the precedent is set, the history of tobacco legislation suggests we’re on a slippery slope to ever-greater infringements on consumer freedom and choice.

One might think that government advice about diet and lifestyle should be followed because it is probably backed by sound evidence. But even in major developed countries, that is not always the case. The general advice to reduce salt intake, for example, has little basis in science, and in fact, government guidelines may be too low for good health in otherwise healthy adults.

Perhaps most famously, the low-fat diet guidelines adopted by the governments of the United States and the United Kingdom in 1977 and 1983 respectively, aimed at reducing the incidence of obesity and coronary heart disease, were not supported by any evidence whatsoever. Yet people followed the advice. Doctors advocated cutting down on fat. Food manufacturers lined supermarket shelves with low-fat and fat-free foods because that is what customers demanded. Low-fat became an ideology, blindly promoted by physicians, the government, the food industry, and the media.

But the advice backfired catastrophically. The substantial reduction of fat in American diets since 1977 marked the start of a sharp rise in obesity and diabetes. The declining trend in coronary heart disease was already well underway by 1977, when the diet guidelines were issued, and are largely attributable to better public health infrastructure and advances in medical care.

The low-fat diet also led to negative dietary consequences, such as the substitution of calories from fat with calories from carbohydrates, and the increased use of sugar and trans fats in manufactured and restaurant food. Yet as recently as 1995, the American Heart Association Diet included such “healthy” snacks as cookies, candy, sugar, honey, jam and marmalade. Where’s the facepalm emoticon when you need it?

“I’m not saying the advice is always wrong, but when it comes to health and diet we need to be much more cautious and critical of ‘official’ advice and recommendations,” writes Tim Spector, in his excellent book, The Diet Myth.

A genetic epidemiologist who has published hundreds of papers on nutrition based on extensive twins studies, he adds: “These knee-jerk responses are often based on insufficient evidence or bad science, or simply a reluctance on the part of politicians and scientists to change tack for fear of ‘confusing’ the public and losing face.”

Since the catastrophic failure of the low-fat dietary guidelines, politicians have landed on a new theory. A simple restriction of calorie intake, they believe, will reverse the obesity trend. In 2018 the UK started a campaign to reduce obesity by recommending a calorie restriction plan: eat 400 calories for breakfast, 600 for lunch, and 600 for supper.

Critics have called this diet insufficient for growing children, and noted they are close to war rations. Many traditional British meals, like Sunday roast or fish and chips, fall foul of these recommendations.

Confusingly, UK government guidelines recommend 2,500 calories daily energy intake for men and 2,000 calories for women, which means three square meals a day will not be sufficient for adults. In fact, men need a whopping 57% more calories than the government says they should get from breakfast, lunch and supper. Bring out the beers and snacks, lads!

The South African Guidelines for Healthy Eating (which appears to have vanished from the Department of Health website) recommend a very similar calorie intake. Children aged five to nine should eat 1,550 calories daily. From ten to thirteen, both girls and boys need 2,000 calories. As teenagers, girls need up to 2,500 calories per day, but that goes back down to 2,000 calories per day for adult women. Teenage boys and adult men need 2,500 calories daily.

Of course, the British government did not stop there. It proceeded to make children run a mile every day and force restaurants, cafés and takeaway outlets to display calorie counts, despite there being no shred of evidence to suggest that this sort of legislation works.

Conducting calorie testing to comply with labelling laws is already expensive, raising the price of food and imposing a heavy burden on small restaurants and cafés, but the British authorities weren’t done. They went full totalitarian, proposing precise maximum calorie counts for all common foods.

And those counts are draconian. Convenience meals will be capped at 544 calories. Sandwiches and main meal salads will be limited to 550 calories. Restaurant main meals will be restricted to 951 calories. Thousands of individual food items will have individual calorie restrictions imposed upon them. These rules will dramatically reduce portion sizes, effectively turn all food into diet food, and prohibit many common fast foods.

Chris Snowdon, head of lifestyle economics at the Institute of Economic Affairs, told the Telegraph newspaper: “These demands are worthy of Nero or Caligula.”

It is sheer madness to enshrine dietary guidelines in law. People aren’t statistics, and even in the statistics, there is a great deal of variation. We all know people in the United States eat too much and are too fat, on average. But even there, that is not true for everyone. There is a rough correlation between daily energy intake and the share of people who are overweight or obese, but a correlation isn’t an iron rule of causation that applies to everyone.

Even at the country level, there are widely divergent relationships between calorie intake and the number of overweight people. In Bolivia, the average daily calorie intake for adult men has ranged between 2,000 and 2,225 since 1975, which is well below the British and South African guidelines. Yet the percentage of overweight and obese men has risen from 26% to 48% in that time. South Korean men had a daily calorie intake of over 3,000 in the 1970s, but the overweight percentage was below 10%. In Botswana, calorie intake ranged between 1,900 and 2,300 since 1975, but the share of overweight men rose from 9% to 30%. In many other countries, like Mongolia, Haiti, Yemen, Equador, Pakistan, Senegal, Guatemala and Swaziland, men consistently eat less than the recommended daily intake in South Africa or the UK but did not escape the rising overweight and obesity trend since 1975. For a great interactive chart, as well as many other obesity-related statistics, see Our World In Data.

In other studies, it also isn’t clear that mere calorie restriction will curb obesity. Spector found no weight difference between a sample of equally obese identical twins, in which one twin had been on calorie-restriction diets regularly for 20 years, while the other had not. Conversely, he overfed lean twins, and although they were on identical food and exercise regimens, one gained three times the weight the other did.

A government decree that restricts everyone’s calories is nonsensical. Worldwide, more than 60% of people are at or below a healthy weight. About 10% are underweight. One-size-fits-all government mandates do not account for this. They also do not account for the very different dietary needs of, say, manual labourers and sedentary office workers, or sportspeople and government officials. Is it fair to make a healthy low-wage labourer buy two sandwiches instead of one, just because the government thinks overweight people shouldn’t have access to nice big sandwiches (unless they’re government officials)?

There has been a backlash in the UK against the proposed calorie tyranny, but Dame Sally Davies, the head of its public health authority, proudly declares herself “chief nanny”. She wants to extend the tax on sugary drinks to a wide range of “unhealthy” foods, containing too much sugar, salt, or fat for her liking. Her confidence belies the fact that nanny-state legislation has rarely, if ever, succeeded in achieving measurable long-term public health improvements.

When the government pays for your healthcare, the government thinks it can police your diet and lifestyle. Like Davies, Health Minister Aaron Motsoaledi has warned that the sugary beverage tax that went into effect in 2018 was only the beginning.

To be fair, he did once acknowledge that undernutrition is also a problem in South Africa, and advocated “policies and interventions” that are “more focused and custom designed”. But that is an ideal which is not reflected in any of his actual interventions against salt and sugar.

“The most dangerous [diet myth] is the notion that we all respond to food in the same way,” writes Spector.

“We are all different. This is why the obsession with the limited view of nutrition and weight as calories-in versus calories-out is unhelpful and distracting. The truth is each of us responds to food differently even if the food and the environment are identical.”

The differences are due in part to genetics, but also to the make-up of our gut microbes. That isn’t to say that a diet high in sugar is good for you, or that you shouldn’t eat lots of vegetables. It isn’t, and you should. But there is no one-size-fits-all solution that is easily amenable to government regulation.

A healthy diet is very varied, including lots of different kinds of vegetables, but also other foods that sustain a healthy gut microbiome. It isn’t so much about how much you eat, but how well your body can digest food. Getting that variety, however, means government interventions that raise the cost of food will do more harm than good.

Since Motsoaledi is ideologically committed to socialised healthcare, perhaps he can take a leaf out of the private sector’s book and offer people incentives for healthy diets and healthy living, instead of punishing everyone equally. Manipulating the evidence and trampling over our rights is not the way forward.

We should fear the food tyranny that is unfolding around the world. Governments are not all-wise, and people are not all the same. Draconian one-size-fits-all dietary interventions – as appealing as they are to authoritarian nannies like Motsoaledi – are likely to harm as many people as they help, if they help anyone at all. Let’s keep government out of the pantry, and make sensible choices for ourselves. DM