When American science writer Gary Taubes released his controversial New York Times bestseller Good Calories, Bad Calories he argued that obesity was caused by certain kinds of carbohydrates, not from eating too many fats or calories.
Taubes also argued against the concept that a low-fat diet promoted weight loss and good health.
In his 2011 book, Why We Get Fat, Taubes advocated a high-fat, moderate-protein, low-carb diet, claiming that if you reduced carbs you could eat all the fat and protein you liked.
Why? Because carbohydrates increased insulin, which boosted sugar, which turned to fat.
"I think the world is full of people who have done exactly what they've been told by the public health nutritional authorities," Taubes told Mind&Body from his US base.
"They've eaten low-fat meals, avoided saturated fats, eaten their fruits and vegetables, their skinless chicken breasts and salmon, and not only have they gotten ever fatter, they've gotten pre-diabetic or gone from pre-diabetic to diabetic.
"What I'm arguing is that we get fat because of the carbs in the diet, not because we're sedentary or just eat too much, and that implies that if we reduce the quantity of carbs in the diet and improve the quality - get rid of the sugars and lower the glycemic index of the carbs we do eat - we'll be leaner and healthier."
Who is this man and is he really qualified to talk weight loss?
Gary Taubes is a journalist who studied science and physics at the prestigious Harvard and Stanford universities in the US.
He has won the Science in Society Award of the National Association of Science Writers three times and shot to notoriety in the nutritional world when he began claiming - loudly - that the main cause of obesity in modern Western society was from the explosion of refined grains and sugars (sucrose and high-fructose corn syrup) in our diets.
"The argument I've been making is that obesity, just like diabetes, is a hormonal disorder of insulin signalling.
"The hormone insulin is the primary regulator of fat accumulation in our fat cells. The obvious cause of obesity should be the excess secretion of insulin that comes with the kinds of carbs we consume in our diets."
Sound familiar? US cardiologist Robert Atkins set the diet world ablaze with his controversial no-carbs diet, which was embraced by Hollywood celebrities and many other dieters during the Noughties.
Taubes is often compared with Atkins, something he considers a good thing.
However, Dietitians Association of Australia spokesman Alan Barclay said Taubes' theories were flawed.
"They focus too narrowly on the sugar fructose and ignore the fact that all carbohydrates can raise blood insulin levels - this is a fundamental flaw," Dr Barclay said.