By Dr. Robert Lustig || The Sydney Morning Herald || April 22, 2017
Australia is in the grip of the twin crises of obesity and type 2 diabetes, and despite all efforts, it continues to worsen. A staggering 280 Australians develop diabetes every day. That’s one person every five minutes with a total annual cost impact of diabetes in Australia estimated to be $14.6 billion.
There are so many dietary factions out there. Do you listen to the “low calorie” camp, the “low fat” camp, the “high protein” camp, the “low carb” camp, or the “low GI” camp? They all say they’ve got the answer for what ails you.
Efforts on the part of individuals to lose weight through caloric restriction or increased exercise are rarely successful; and if they are, the weight loss doesn’t last very long. It’s assumed that people who are obese are “non-compliant” or “weak-willed”. Rather, they are fighting a losing battle. Following current dietary advice is counterintuitive to achieving a healthy weight.
The reason is the myth of energy balance. If you believe this, then you believe that obesity is a physics problem; too much energy in, too little energy out. Energy balance assumes that all calories are equal, no matter where they come from. Rather, obesity is about energy deposition into fat tissue. Obesity is a biochemistry problem, and where those nutrients came from determine where they go in the body. It’s called nutritional biochemistry and it shows that all calories are not created equal.
Studies show that sugar is slowly killing people around the world. Photo: Andrew Quilty
Rather, it’s the insulin response that determines whether any given calories will deposit into fat tissue or not.
Insulin has two roles in the body. The first is to store energy in fat cells, driving weight gain. The second is to block the signal of the hormone leptin in the brain.
Leptin is a hormone made in fat cells. When leptin works as it is supposed to, it tells the brain that we do not need to eat so much and then we can burn energy at a normal rate.
High insulin levels can block the action of leptin in the brain and trick our body into thinking it’s starving. How do you feel when you’re starved? Hungry and slothy. Obesity is brain starvation. This explains how elevated insulin levels block leptin signalling, and therefore increase food intake, decrease activity, and promote weight gain.
Put simply, insulin drives all of the behaviours seen in obesity. The biochemistry comes first.
In Australia, almost two in three people are overweight or obese and 6 per cent have diabetes; this number has tripled in just 15 years. I believe one of the main culprits is sugar in the Australian diet.
Most people think sugar is just another form of over-consumed kilojoules. Our research says otherwise. We have shown that sugar is toxic (unrelated to its calories or its effects on weight gain) and directly responsible for a host of chronic diseases.
Dietary sugar (sucrose) is composed of two molecules, glucose and fructose. While the glucose raises insulin and promotes weight gain, it’s the fructose that leads to chronic diseases like diabetes. Fructose is metabolised in the liver in the same way as alcohol, so it should not be surprising that children now get the diseases of alcohol (type 2 diabetes and fatty liver disease) without consuming alcohol.
Our research shows that total caloric availability is unrelated to diabetes prevalence worldwide. For every extra 150 calories per person per day available in any country, diabetes prevalence rose by only 0.1 per cent. But if those 150 calories per day happened to be a can of soda, diabetes prevalence rose 11-fold, by 1.1 per cent. In fact, we have proof-positive data that sugar causes four chronic diseases: type 2 diabetes, heart disease, fatty liver disease, and tooth decay.
Sugar also stimulates the reward centre of the brain similar to what nicotine, heroin, or alcohol does, driving continued consumption.
Studies show that sugar is slowly killing people around the world, anywhere the Western diet has replaced indigenous diets. Sugar is ubiquitous, appearing in virtually every processed food, and so it’s not easy to reduce your consumption of sugar.
The World Health Organisation recommends limiting our intake of free sugars to no more than 10 per cent of total daily energy intake to reduce the risk of metabolic disease, such as diabetes.
In Australia the guidelines say just 5 per cent of the daily diet, or about six teaspoons, can come from added sugars, but Australians actually eat double that – more like 14 teaspoons.
The easiest way to dramatically cut down on sugar and fructose consumption is to switch to a diet of “real” i.e. whole, unprocessed foods. But this is not what the food industry is selling.
And all those dietary factions? There are two things that every successful diet out there shares. They’re all “low-sugar, high-fibre”. Because they’re all REAL food. Processed food is the enemy.
Reducing sugar and processed food and turning back the obesity and diabetes epidemics won’t be easy but it’s up to each and every one of us.