Dr. Robert H. Lustig begins with the question, “What do the Atkins diet and the Japanese diet have in common?” It’s an odd question, as the two diets seem diametrically opposed. The Atkins diet is all fat, no carb. And the Japanese diet is all carb, no fat. They both work. So, what do they have in common?
They both eliminate the sugar fructose.
Lustig continues into a 90-minute lecture, called “Sugar: The Bitter Truth,” which can be viewed for free on Youtube. Amazingly, this 90-minute talk on sugar and biochemistry was viewed by over 1.5 million people. 1.5 million people wanted to learn how fructose is basically the common denominator for virtually every aspect of Metabolic Syndrome.
Lustig begins with a basic law: if you eat it, you better burn it, or you’re going to store it. This is the law of thermodynamics, pushed forward by fitness trainers and fad diets. For many, it’s true. Calories in vs. calories out will determine skinny or fat.
But it’s not true. I’ve always said that if you eat 2,000 calories of protein vs. 2,000 calories of sugar, you will achieve a very different body shape.
Energy expenditure equals quality of life, Lustig continues. The more energy you burn, the better you feel. But we are not burning this energy, and America is suffering from an obesity epidemic.
There is a hormone in our body that tells us to stop eating. It’s called leptin. It’s supposed to tell us to stop eating, but Americans are eating more than ever, so clearly leptin isn’t working anymore. There is something we are eating that is distorting our normal biochemical negative feedback system.
Is it the fat in our diet?
Nope, he says dismissively. We’ve actually decreased our fat intake, as a country, from 40 to 30% over the past few decades.
It’s the carbs, Lustig declares. There’s something in the carbohydrate we are eating that has shut down leptin.
Americans consume 65 lbs of high fructose corn syrup a year. HFCS is much sweeter than most sugars. The syrup is comprised of glucose and fructose (fructose will vary from 42-50%). Sucrose (table sugar) is also a fructose and a glucose; table sugar is 50% glucose, 50% fructose.
Lustig declares, HFCS and sugar are the same. They are both poison. Sugar isn’t just about empty calories. Fructose is a poison, and it distorts your body’s chemistry.
Every single year, Americans not only eat more, but they eat more of their calories from sugar.
After summarizing how the Nixon administration would change the face of American food production and culture forever, and the tight correlation between soft drink consumption and obesity, Lustig asks his audience to hang on tight for a whirlwind tour of how glucose, fructose, and ethanol (alcohol) break down in the body.
Fructose is not glucose:
1. Fructose is 7 times more likely to form advanced glycation end products
2. Fructose does not suppress ghrelin (the hunger hormone) because it does not break down until it reaches the liver.
3. Fructose does not stimulate insulin or leptin.
4. Fructose is the only sugar metabolized by the liver.
5. It promotes metabolic syndrome.
Compare 2 slices of white bread (which is roughly 120 calories of glucose), to liquor (roughly 120 calories of ethanol), to a glass of a sugar-sweetened beverage (about 120 calories of sucrose, half of which is fructose).
The Bread (glucose) – 120 calories:
-80% of the glucose will be used by the body.
-About 20% of the glucose will hit the liver and get stored as glycogen (for future physical activity).
-A tiny fraction of the glucose will be made into ATP which, if not burned, will go through a number of biochemical processes, turning into citrate, and may be stored as fat.
-Perhaps 1/2 a calorie will end up as Pattern B Cholesterol (very low density lipoprotein), but it is negligible. This is why you can live off white rice and not die of a heart attack.
The Alcohol (ethanol) – 120 calories:
- 24 calories will hit the kidneys, muscle, and brain.
-96 calories hit the liver. This is four times the amount, compared to white bread (glucose).
-What hits the liver metabolizes into acetaldehyde (like formaldehyde), which is toxic.
- Like glucose, it breaks down into lots of citrate, and will be stored as fat (four times the amount!).
-The other by-product of this metabolic process is the production of Pattern B Cholesterol (VLDL), again, four times the amount.
The Sugary Beverage (sucrose) – 120 calories:
-60 calories from glucose will break down similarly to the white bread (48 calories to the body, 12 calories to the liver to be stored as glycogen).
-60 calories from fructose will all go to the liver.
-In total, 72 calories reaching the liver will need to be phosphoralated (turned into energy–ATP–adenosine tri phosphate). That is a lot–three times the amount, when compared to white bread.
-You lose a lot of phosphate in this process, and so the body provides a rescue molecule, and the end waste product from the metabolism of these calories is uric acid (which causes gout and hypertension, among other things).
-Uric acid blocks the your body’s chemical–endothelial nitric oxide synthase–for maintaining low blood pressure.
-Citrate, again, arises from the metabolism of all these calories, which promotes fat retention, dyslipidemia, VLDL, and high blood triglycerides.
-In short, from any fructose load, 30% of it will end up as fat.
-An excess of body fat changes the way your body responds to leptin. Leptin is a hormone produced by adipocytes (fat cells). The more fat you have, the more leptin is produced to act on your brain’s hypothalamus. But when there is too much, you develop leptin insensitivity; your brain can no longer recognize it and thinks you’re starving. So you eat more.
A final comparison between soda and beer:
|Calories from fructose
||75 (4.1 kcal/g)
|Calories from other carbs
|Calories from alcohol
|1st pass G.I. metabolism
|Calories reaching the liver
Lustig says fructose is ethanol without the buzz.
Fructose is like drinking fat. 30% goes to fat storage. It is metabolized like fat.
A high sugar diet is essentially a high fat diet.