The Bitter Truth About Sugar

The video I am posting here, Dr. Lustig’s video lecture The Bitter Truth About Sugar, has some major flaws. He is spot on with the dangers of replacing a part of one's normal diet with high fructose corn syrup. It is metabolized quite differently than other carbohydrates. In fact it is digested in a similar way to alcohol. Eating such an unnatural product in the quantities many in the US consume cannot be good.

I think he is greatly oversimplifying. Looking at other interviews he has done, he said that carbohydrate and fat cannot exist in the same food. This is really strange, because they do. To make the details of what he is proposing even more confusing, he said that fruits are all right because they have fiber. Well, that depends on the fruit. Bananas have little fiber.

Even vegetarians like Dr. McDougal recognize that fruits can play a negative role in the formation of triglycerides, which are associated with heart disease. More discussion of this would have strengthened Lustig’s case.

He also said in the video that early humans ate 100 to 300 grams of fiber a day. That is rather high. Most estimates I have read place it at 100 grams. The only way they got this much was that ancient foods had not been artificially selected to make them sweeter and have more carbohydrates.

The recommendation is that humans should consume 25 grams. The average in America today is 12. Obviously there is room for improvement. Today I ate 55 grams of fiber, 15 of it artificial from a protein bar. How did I get the other 40 grams naturally? I ate a grapefruit, a banana, an apple, and one cup of strawberries. I also ate 3 cups of Brussels sprouts and three cups of various types of lettuce. I also got fiber from nuts. I had some spinach and beans with my fish. With this huge fiber feast, I still only got 40 grams of fiber. To approach what our ancestors ate may not be practical. (For those curious I am trying various dietary combinations to see how I feel.)

So while I have some reservations about Dr. Lustig's presentation due to oversimplification of complex issues, the reminder of the dangers of fructose is something that needs consideration. I doubt I will eat as much fruit as I did today on a regular basis. That seems like too much fructose. Lustig's explanation of fructose metabolism makes that clear to me.

Here is how Gary Taubes, no friend to sugar, describes the talk in the NY Times:

It doesn’t hurt Lustig’s cause that he is a compelling public speaker. His critics argue that what makes him compelling is his practice of taking suggestive evidence and insisting that it’s incontrovertible. Lustig certainly doesn’t dabble in shades of gray. Sugar is not just an empty calorie, he says; its effect on us is much more insidious. “It’s not about the calories,” he says. “It has nothing to do with the calories. It’s a poison by itself.”

Taubes presents a much more balanced approach, I recomend the whole article he wrote as a supplement, or substitution, to this viral video.