I just came across a quote by Dr. Robert Lustig. This is his bio on Wikipedia:
Robert H. Lustig is an American pediatric endocrinologist at the University of California, San Francisco (UCSF) where he is a Professor of Clinical Pediatrics. He practices in the field of neuroendocrinology, with an emphasis on the regulation of energy balance by the central nervous system. He also has a special interest in childhood obesity.
On May 26, 2009, he delivered a lecture called “Sugar: The Bitter Truth” which was posted on YouTube the following July and “went viral” with some 4.9 million viewings (as of Aug 4, 2014).
Dr. Lustig is an endocrinologist specializing in obesity and energy balance. He is known for calling sugar a “toxin” and a “poison”. In this video:
At about 2:17 he said:
It’s when you put fat and carbohydrate together that they don’t work. And sugar because of its unique composition is the only food on the planet that is both fat and carbohydrate at the same time. Even fatty fruits, coconut, olive, avocado, have no carbohydrate. There is no food stuff on this planet that has both fat and carbohydrate at the same time. It’s one or the other. Because that’s evolution. That’s nature. That’s what God did. Except for sugar.
But sugar does not contain fat. And many whole foods contain both fat and carbohydrate, including the ones he said that do not. I don’t believe he doesn’t know this.
Sugar, granulated, 1 teaspoon:
Total fat: 0g
Total carbohydrate: 4g
Coconut meat, raw, 1 cup shredded:
Total fat: 27g
Total carbohydrate: 12g
Avocado, raw, 1 cup cubes:
Total fat: 22g
Total carbohydrate: 13g
Cashew nuts, raw, 1 ounce:
Total fat: 12g
Total carbohydrate: 9g
My first thought was that he was referring to sugar-containing processed foods that almost always contain fat. But that isn’t it. He says in the video that fructose, which makes up 50% of table sugar, can be converted to fat. Is that what he means? But there are several fates for dietary fructose other than fat production. It can enter glycolysis for one (which gives us energy in the form of ATP). It can be metabolized to provide raw material to make amino acids or other sugars.
I don’t think sugar – the white, crystalline stuff that’s added to processed food – is a health food. But nor do I think it’s the primary culprit behind the obesity epidemic.