It’s been heralded as the tipping point in the official guidance we’ve been given about healthy eating over the past 40 years. The saturated fats we eat—mainly from meat, butter and cheese—don’t clog our arteries and cause heart disease after all, and all along, the real culprit has been sugar.
Obesity, diabetes and heart disease are related to insulin intolerance, new research is discovering. Insulin breaks down the sugars in carbohydrates, so the more carbohydrates we eat, the more insulin is produced. But this can reach overload when we eat lots of carbohydrates that have added sugar—such as found in processed and ‘white’ foods. The extra insulin gets stored as fat and so begins the inflammatory process that leads to diabetes and heart disease.
Yet, the saturated fats theory gave birth to the multibillion low-fat and diet-food industry—and ironically launched processed foods that are high in sugar—and doctors are only now beginning to accept it was based on bad science or, sometimes, no science at all.
Over the years, health advisors have been recommending we eat less and less saturated fat and, today, we are told that saturated fat should make up no more than 10 per cent of our total daily caloric intake.
But it now looks like that advice was wrong, although it’s not going down without a fight. Two doctors, one in South Africa and the other in Australia, have been facing disciplinary charges for advocating a high-fat diet, with one of them having to defend an additional charge that he “inappropriately reversed a patient’s type 2 diabetes” by changing the patient’s diet.
A tipping point
A pivotal moment for the fats theory happened last December, when the British Medical Journal (BMJ) refused to retract an article that had criticized the US Dietary Guidelines for Americans (DGAs) for continuing to advocate a high-carbohydrate, low-fat diet for heart health.
The US advocacy group Center for Science in the Public Interest (CSPI) had campaigned to have the article withdrawn, but two independent reviewers looked at the evidence and agreed with the article’s conclusions that the DGAs had ignored swathes of evidence that contradicted the low-fat theory. Worse, the reviewers—Mark Helfand, at Oregon Health & Science University, and Lisa Bero, at the University of Sydney—said that advocates of the diet had conflicts of interest. In other words, those scientists had been funded by a food industry bankrolled by its low-fat products.
Ignoring the evidence
The original article—by investigative journalist Nina Teicholz—hadn’t pulled its punches. Teicholz, who also wrote the book The Big Fat Surprise (Simon & Schuster, 2014), had been commissioned by the BMJ to look at the science behind the DGAs’ dietary guidelines for 2015, a review it undertakes every five years.1
Its latest guidelines recommend that we should get just 10 per cent of our calories from saturated fat in meat and dairy, and advises that we follow one of three healthy diets: the healthy vegetarian diet; the healthy Mediterranean-style diet; or the healthy US-style diet.
But, argues Teicholz, the DGAs committee of 15 experts had either ignored recent evidence contradicting the low-fat theory or placed too much significance on other studies. The recommendations for the three diets were also based on a “minuscule quantity of rigorous evidence” that “only marginally supports claims that these diets can promote better health than alternatives”.
Within days of the BMJ declaration—hailed by Prof Tim Noakes, a South African expert in nutrition, as “a tipping point”—a group of around 200 Canadian doctors presented an open letter to their government urging radical reform of its advice on nutrition. They pointed out that there has been an explosion in rates of obesity, diabetes and heart disease in the 40 years since the low-fat diet has been promulgated.
In fact, the diet actually worsens the risk factors for heart disease, they argue, and they also say that doctors and nutritionists should be free to advocate other dietary approaches, such as the low-carb diet, for people with diabetes and heart disease.
These demands echo those of the US Nutrition Coalition and the UK Public Health Collaboration, which are also calling for more open discussion about diet and the failings of the low-fat approach.
Such calls for greater freedom of speech—and freedom to treat—follow hearings against two doctors who had prescribed a high-fat diet to their patients. Dr Gary Fettke, an orthopaedic surgeon in Tasmania, has subsequently been barred by Australia’s medical governing body from recommending the diet or even talking about it, while the case against Prof Noakes in South Africa is ongoing.
Since the gag order on Dr Fettke last November, he now faces new charges that he reversed a patient’s type 2 diabetes “inappropriately”—by recommending a high-fat diet.
The new charge was made almost immediately after a secret hearing of Australia’s medical regulator, the Australian Health Practitioner Regulation Agency (AHPRA), banned Dr Fettke from talking about a high-fat diet or treating patients with it.
The original case was brought by a dietitian—who has remained anonymous—who claims Fettke wasn’t qualified to recommend a dietary approach.
It’s the diet
In his testimony, Dr Fettke, who practises in Tasmania and lectures at the local university, told AHPRA: “My patients are lying around in hospital with obesity-related conditions, amputated limbs and non-healing rotting flesh. I believe it is the nutritional advice that they have been given that has put them there in the first place.”
He also said that the evidence for a low-fat diet was “wanting in substance and riddled with vested-interest politics”.
In a separate trial, one of South Africa’s leading dietary experts, Dr Tim Noakes, has been defending his low-carb, high-fat (LCHF) approach to the Health Professions Council of South Africa (HPCSA), after being accused of giving misleading advice to a new mother via Twitter. In the Tweet, Noakes, a professor at the University of Cape Town, told the mother—who had asked for his advice—to wean her baby onto the “real” foods of the LCHF diet.
The HPCSA hearing was triggered after dietitian Claire Julsing Strydom, former president of South Africa’s Association for Dietetics, lodged a complaint against him. It’s been hailed as the ‘Nutrition Trial of the Century’ and the ‘Banting for Babies’ trial, after the British undertaker who lost three stone (19 kg, or 42 lb) after eliminating sugar, starch and beer from his diet. Banting, who died in 1878, was the first best-selling author of a diet book.
Although the final arguments won’t be heard until next April, sceptics fear the tribunal is nothing more than a celebrity show trial, a view that wasn’t helped by an announcement by the HPCSA at the end of last October that Noakes has already been found guilty of unprofessional conduct. The Council retracted the announcement two hours later, claiming it had been issued in error.
Noakes argued in his hearing that the advice he had given the mother was neither unconventional nor dangerous, and that evidence supporting it can be traced as far back as the 1800s. Saturated fats are what our forebears ate, and that was in an age when diabetes and heart disease weren’t the epidemics they are today.
Know your fats and carbs The fats
Unsaturated fats. These ‘good’ fats come in two varieties: monounsaturated fats, typically found in olive oil, nuts, seeds and avocados; and polyunsaturated fats, found in sunflower oil, walnuts, flaxseeds and fish. An important polyunsaturated fat is omega-3, found in oily fish, flaxseeds and walnuts.
Saturated fats. These are mainly found in meat and dairy products like cheese and milk, but also in coconuts and coconut oil. However, saturated fats are also abundant in pizzas, biscuits (cookies), hamburgers and fast food.
Trans fats. These are created by a process called ‘hydrogenation’, where hydrogen is added to liquid vegetable oils to make them solid at room temperature—for example, margarine and shortening for baking and frying foods. Partially hydrogenated oils are used by restaurants and the food industry for frying, baking and processing fast foods. Trans fats are also found naturally in small amounts in beef and dairy fat.
Carbohydrates are most commonly found in sugars, fibres and starches. They provide the body with glucose (blood sugar), which is converted into energy that keeps the body functioning, and come in two forms: simple and complex.
Simple carbs can be either monosaccharides, which means they contain just one sugar, such as fructose (in fruit) and galactose (in dairy), or disaccharides, which have two sugars, such as sucrose (table sugar), lactose (dairy) and maltose (beer and some vegetables).
Complex carbs, or polysaccharides, have three or more sugars, and are often found in starchy foods, such as beans, peas, lentils, potatoes, corn, parsnips, whole-grain breads and cereals.
Simple carbs give a sudden energy boost and can cause a spike in blood sugar levels, while complex carbs provide more sustained levels of energy.
Birth of a theory
The idea that saturated fats cause heart disease was promoted by Ancel Keys, a researcher at the University of Minnesota. It started to change public-health policies after Keys published his famed Seven Countries Study in 1970, which suggested that the populations that traditionally ate less meat in their diets also had lower rates of heart disease.1
At around the same time, Prof John Yudkin at the Queen Elizabeth College in London was arguing that the real culprit was sugar, but this theory was largely ignored at the time, only to be rediscovered in the past few years.
By 1977, the US Senate Select Committee on Nutrition and Human Needs was recommending a new healthy diet of 60 per cent carbohydrates and 40 per cent fats to reduce the risk of heart disease, cancer and stroke.
However, the evidence for such a diet was weak, prompting Philip Handler, president of the US National Academy of Sciences at the time, to describe it as a “vast nutritional experiment”.
Then, not long after the new food pyramid was announced—with carbohydrates forming the base—rates of obesity rose dramatically.2 More worrying still, diabetes—a precursor of heart disease—and cardiovascular disease itself also started to rise and, today, heart disease is the biggest killer in the West.
This is because obesity and heart disease have nothing to do with the saturated fats we eat, but are caused by the higher levels of insulin our bodies are forced to produce to break down the sugars in carbohydrates, says Osama Hamdy, a diabetologist at Harvard Medical School.3
The higher levels of insulin are stored as fat, which triggers inflammation that, in turn, causes insulin resistance, which leads to even more insulin being produced—and the final result is atherosclerosis, or hardening of the arteries.
As Hamdy argues, until the fats theory gained traction, diabetes had always been seen as a disease of carbohydrate (sugar) intolerance and treated with a low-carb diet. One doctor, Elliott P. Joslin, successfully treated his patients suffering from ‘fatty diabetes’—called ‘type 2 diabetes’ today—with a diet of just 2 per cent carbohydrates and 75 per cent fat.