For more than 50 years we have been told to cut fats out of our diet, but more recently the dangers of sugar in the Western diet have been exposed. At a time when the world has become obsessed with the dangers of sugar, one would think that our populations would be healthier.
Despite growing knowledge, Australia remains one of the fattest nations in the world. According to government reports, 65 per cent of Australian adults and 25 per cent of Australia children are now overweight or obese. The situation is mirrored in New Zealand, with 66 per cent of adults and 33 per cent of children in these categories.
What’s more, diet-related chronic diseases such as heart disease, stroke, type 2 diabetes and some forms of cancer are currently the major causes of premature death and disability among adults across most of the Western world.
The reason for this, according to the government, is that Australasians follow a poor diet, with an excessive intake of energy-dense, relatively nutrient-poor foods that are high in saturated fat, refined sugars or salt. To combat this, health bodies in both countries advocate consumers follow the government-backed guidelines: the Australian Dietary Guidelines as commissioned by the National Health and Medical Research Council and the Eating and Activity Guidelines as commissioned by New Zealand’s Ministry of Health.
Both recommend a balanced diet containing plenty of fruits and vegetables, grain foods, lean meats and reduced-fat dairy products.
A new approach
Now a new school of thought is turning government advice on its head, saying fats are back and carbohydrates are out. In their new book What the Fat?, Professor Grant Schofield and dietician Caryn Zinn – along with chef Craig Rodger – argue that the key for a healthy lifestyle is a diet low in carbohydrates and high in healthy fats.
The low carb, healthy fat (LCHF) lifestyle became apparent to Schofield when he was working for the World Health Organisation in the South Pacific.
Commissioned to work to prevent diabetes and non-communicable diseases across a number of islands, Schofield observed two extreme cases that challenged him to question the norm of reducing fat intake.
In southern Vanuatu, Schofield observed the locals eating a traditional diet, reliant mostly on fish and coconuts – foods naturally high in fat, and saturated fat at that. Here, the community was very healthy with little diet-related illness.
Conversely, Schofield also saw the community on Kiribati Island, which has one of the worst rates of diabetes in the Pacific. Having lost the ability to source food from their natural environment, the people of Kiribati were heavily reliant on processed carbohydrates. Here, Schofield observed chronic obesity and very high rates of type 2 diabetes.
Schofield concluded that what has worked for humans throughout time had nothing to do with the “so-called ‘healthy’ food pyramid”.
“I am now convinced that mainstream nutrition science and practice is based more on dogma, industry-vetted interests, academics ‘playing the game’ to get their research grants and publications and people playing it safe,” he says.
LCHF supporters such as Schofield and Zinn say that, contrary to mainstream nutrition advice, we should be returning to whole foods as found in nature, eating more healthy fats as part of a balanced diet, and remove the need for processed carbohydrates.
The LCHF diet involves eating what it terms as “good-quality carbs” from whole foods such as vegetables (particularly non-starchy vegetables), fruit, legumes and dairy products. These carbohydrates are balanced with protein from minimally processed meat, dairy products, nuts and seeds and fats from whole, minimally processed plant and animal sources.
Dietary guidelines in both Australia and New Zealand advocate a minimum intake of fats and a balanced diet of vegetables, lean meats, reduced fat dairy and whole grain cereals. The big focus here is reducing intake of what government guidelines classify as “bad” fats (those high in saturated fat content such as butter, cream and coconut oil) and replacing them with limited intake of “good fats”, (those foods which contain predominantly polyunsaturated and monounsaturated fats such as oils, spreads, nut butters and avocados).
This very classification of “good and bad fats” is being challenged by LCHF advocates. The vilification of fats, they argue, has resulted in consumers replacing fats with extra carbohydrates. This excessive carb intake, says the LCHF camp, is the real cause of our dietary problems.
Carbohydrates – the Hidden Sugar
What LCHF advocates is to change not only the way we think about fat but also the way we think about carbohydrates. Although the community becomes more and more aware of the adverse effects of added sugar in the diet, there still appears to be a gap in consumer knowledge and the relationship between carbohydrates and sugar. “We know about sucrose, it’s pure white and deadly,” explains Schofield. “But extensively all rapidly absorbed carbohydrates rapidly change your blood sugar, which makes the body hyper-excrete insulin.”
Any time we eat a carbohydrate (be it a vegetable, bread or pasta), our body’s natural reaction is to convert that carbohydrate into glucose. So although we might have learned not to add sugar to our cereal, we must remember that the cereal will become glucose in our blood.
Thus eating carbohydrates as a main source of energy, let alone in excessive amounts, can be a dangerous mix for anyone who is trying to eat healthily. “If you have trouble maintaining a normal blood sugar and have problems with insulin resistance from eating a high-carbohydrate diet, then I don’t think the current guidelines are for you,” says Schofield.
Continually eating large amounts of carbohydrates, especially refined carbs such as those found in white bread, can result in what Schofield and Zinn call being “metabolically dsyregulated”. This is where the body is not able to readily handle glucose and insulin in a way that is normal.
This means that a normal load of carbohydrates can push glucose and insulin levels up for hours on end. The insulin also shuts off the ability to burn fat as a fuel source, making it difficult for people to lose weight. Consumers become increasingly resistant to insulin, meaning that more insulin is required to process the carbohydrates. This can cause havoc for those trying to get weight under control or avoiding type 2 diabetes.
According to advocates of the LCHF diet, if you restrict carbohydrates you solve both problems – the body no longer relies on carbohydrates for energy and consequently begins to burn fat stores. Simultaneously, insulin levels get under control without a daily bombardment of carbs.
“The simple fact is that to live a long and healthy life, you are going to need to control your blood sugar. And before that you need to make sure that you control your insulin,” says Schofield.
What is a “healthy fat”?
However, this isn’t a green light to gorge on fatty foods. Healthy fats are heavily emphasised by the LCHF movement, but what is a healthy fat?
It depends on who you ask. Government guidelines and LCHF agree we should avoid trans fats. These are found in traditionally processed and manufactured foods and offer no nutrient value. However, that is where the consensus ends.
Government guidelines advise including a small serve of fats as part of a balanced diet, replacing high-fat foods with polyunsaturated and monounsaturated fats. Under this view, eating a fresh coconut is fine, but using a lot of coconut oil or cream in cooking is advised against.
LCHF supporters argue the opposite. “I break it down to the simplest level, which is eating fats that are not man made but are found in nature and eating whole foods,” explains Zinn. “And if you truly eat a diet of whole unprocessed foods, they are naturally going to be lower in carbohydrates and higher in fats.”
As a guide, LCHF suggests looking at the “human interference factor” of a food. “Ask yourself, has the final product had to go through a whole industrial process to make it? If so they are probably high in omega-6 acids, they are probably inflammatory to the system and might not be stable to cook with,” says Schofield.
Given that the LCHF approach upends current dietary guidelines, it is unsurprising that government bodies are critical. The Dietitians Association of Australia (DAA) warns of pitting one food group against another in the current context, when 35 per cent of Australians are getting their energy intake from “junk” foods. Meanwhile less than four per cent are eating enough vegetables and legumes. “In this context, we would rather encourage people to go back to first principles of eating a variety of foods for a balanced diet,” says DAA spokesperson and dietician Clare Collins.
A further critique is that a diet high in fats such as triglycerides will raise cholesterol and heart disease. This is based on the “lipid theory” of fats. The Lipid Hypothesis was a position advocated by US researcher Ancel Keys, who said that there was a correlation between fat in diets and cholesterol levels, or fat in the blood. Keys’ study – from 1947 to 1981 – became the main authority for the theory that saturated fat in the diet is a direct factor in raising cholesterol levels and risks of heart disease.
Lipid theory has been accepted by much of the medical community and forms a basis of the Australian and New Zealand dietary guidelines.
Professor Amanda Lee was the Chair of the National Health and Medical Research Council Working Committee, which created the current Dietary Guidelines. “If you look at the data behind the guidelines, you can see over the past 40 years a significant decrease in the rate of heart disease,” says Lee. “And one of the main reasons for that is that we got butter out of the diet and encouraged people to move to safer, polyunsaturated spreads.”
However, there is ongoing tension surrounding this theory, which is at the crux of the “good fat”, “bad fat” debate. “You can see how that was a good hypothesis in that fat is something that has a lot of calories in it and resembles the fat in your arteries so for heart disease that is going to be a problem,” argues Schofield. “It’s a pretty reasonable hypothesis, it just doesn’t turn out to be true.”
LCHF proponents agree that fat in the blood is a bad thing, they just dispute the idea that fat in the diet causes fat in the blood. In making their claims, the LCHF position is based on research including a study commissioned in 2010 where participants were either put on a LCHF diet or a low-fat, high-carb diet. Even though the LCHF group ate three times more fat, and had three more times fat in their food, their blood fats were half of those eating a high-carb low fat diet.
The Fight Against Sugar
Regardless of where one stands on the carbohydrates versus fats debate, one thing is clear – consumers are increasingly pushing back against sugar in our diet. According to a study on food consumption and trends by market research group Ipsos, one in two adult Australians believe that there is too much sugar in packaged food.
Meanwhile a recent report by the World Health Organisation suggests that a tax on sugary beverages would help lower intake and reduce obesity, type 2 diabetes and tooth decay. Finland and France already have a “sugar levy”, with the UK and Northern Ireland planning to do the same.
Carbs – an essential nutrient?
“To single out carbohydrates as an essential food and demonise fats, there is no scientific basis for that. Some people do alright on high-carb diets, however the people who need the most help in terms of obesity and diabetes, don’t. So we end up with a situation where the people who most need to change their diet get the worst advice,” argues Schofield.
Government bodies accept the natural conversion of carbohydrate to glucose in the blood, but argue any negative effect is countered by the nutritional benefits, such as fibre and the production of glucose necessary for healthy organ function.
Cutting out carbohydrates, critics argue, is not only removing these nutrients from our diet, it also reduces the feasibility of adhering to any new diet in the long term.