What if eating fat does not make you fat? It is an idea that could turn decades of established thinking on its head.
The US physicist Gary Taubes has lobbed this scientific ”grenade” in two books he has written about obesity and nutrition. His premise? That the hormone insulin is responsible for obesity, and levels of insulin spike when we eat carbohydrates, leading us to get fat. Eating fat, he says, does not have this effect on insulin and therefore is not the culprit in making people overweight or obese.
The idea that people are fat because they eat too much says nothing meaningful about why excess calories get stored as fat, says Taubes, who studied applied physics at Harvard. He argues that carbohydrates, such as fructose, corn, potatoes, rice and grains, affect insulin, a powerful regulator of fat. Fat is readily stored in the presence of insulin because it causes the enzyme lipoprotein lipase to suck fat inside cells where it is stored. The body only makes insulin when blood sugar levels rise, and all carbohydrates are metabolised as sugar.
Thus, if we do not eat carbohydrates, there will not be excess sugar in the blood, the body will not make insulin and fat will not be stored by cells, Taubes believes.
Meats, fish, eggs, butter and oil contain few, if any, carbohydrates and do not cause insulin levels to spike, which Taubes says means people can eat as much of those foods as they want so long as they also avoid carbohydrates.
”So this idea all calories are created equal; well, in terms of the energy in the calories, yes … but in terms of the fate of the nutrient downstream, the same amount of calories of different nutrients will have a dramatically different effect,” Taubes says.
It is a bold stance to take amid the present epidemic of obesity and diabetes, with Australian public health guidelines staunchly placing the blame on eating too much and not exercising enough.
While his ideas are controversial, they are not completely new. Robert Atkins’s revolutionary Atkins diet in the 1970s had similar ideas, and low-GI diets also follow some of these principles. But Taubes goes deeply into the science behind the high-fat diet, picks apart studies by major universities more rigorously and is doing so at a time when consumers are frustrated by their inability to lose weight no matter which diets they follow.
Taubes is keen for his work to be digested by health experts clamouring to find some solution to the growing obesity epidemic that is threatening to swamp health systems around the world.
Even Australian nutritionists who view Taubes as a conspiracy theorist because of his criticisms of those who pioneered the idea that fat causes obesity, admit his research has enough credibility and science behind it to be considered.
Whether you believe fat is to blame for rising obesity or not, it is clear the problem is getting worse.
More low-fat foods are being produced and consumed than ever before. Red meat consumption is also declining, with beef consumed in the Australian market decreasing by 3 per cent in 2010-11. Yet, obesity rates in Australia are still climbing.
Taubes says it was when gluttony and sloth became demonised as causes of obesity in the 1960s, that the field of nutrition lost its way while waistlines continued to grow.
”Pre-World War II, all of the best science was done in Europe where there was a culture of excellence in physics, biology and medicine,” he says.