Review and summary of “Sugar: The bitter truth”
Dr. Robert Lustig lectures on the perils of sugar, Fructose in particular.
He talks about how obesity has risen at the same time as fat consumption has decreased, how soft drinks and the invention of High-Fructose Corn Syrop are two of the larger culprits and the biochemistry of Fructose.
Below I have summed up the lecture in plain English, simplifying facts and eliminating scientific terms. Towards the end I sum up a few points from a rebuttal and end with my own opinion of the lecture.
* We are eating more calories than before. This wouldn’t happen if the brain were suppressing your appetite properly. The suppressor is being circumvented.
* Coca Cola uses sugar to hide how much salt it contains. The salt is there to make you thirsty again. (I have been unable to confirm that Coke contains any salt)
* All countries that have adopted the US diet are having the same problems with obesity, heart disease and diabetes.
* Up to 30% of Fructose is metabolized into fat. A low-fat high-Fructose diet isn’t really low-fat.
* Fat consumption has reduced by25% in the last three decades. At the same time obesity has increased.
Summary of the movie:
We all weigh 25 pounds more than we did 30 years ago because we eat more calories.
Obesity is a problem for children down to 6 months old.
There is a mechanism in the body that is supposed to tell you when you are full. The only way to eat more than you should is to suppress this mechanism.
The extra calories we are eating come from carbohydrates like sugar and not fat. (Note that the speaker uses figures for 1-17 year olds to demonstrate this point and that this does not hold for adults where calorie consumption has increased across the board)
All countries that have adopted the US diet have this same problem.
In the last three decades fat consumption has decreased 25% and yet obesity has increased. During this time there has been a 41% increase in the consumption of soft drinks.
Coke uses sugar cleverly to disguise all the salt they put in it to make sure you get thirsty again very shortly. The caffeine augments this effect as it makes you pee. (Note that I have been completely unable to confirm that Coke contains any salt at all, it does contain high quantities of sodium, which usually indicates salt, but this may also be because of the preservatives they use)
Consumption of soft drinks has been shown to increase odds of obesity and type-2 diabetes.
High Fructose Corn Syrop:
High-Fructose Corn Syrop (Glucose-Fructose in Canada, Isoglucose in Europe) is an extremely common replacement for white sugar (Sucrose). It is made from corn and contains about 55% Fructose and 45% Glucose, while Sucrose contains exactly 50% of each.
HFCS is sweeter than Sucrose, by ca. 20%. It is also cheaper to make, which is why it is extremely popular in food production. The average American eats 63 pounds (30kg) of it each year.
The speaker asserts that HFCS is no worse for you than any other source of sugar. (This is highly debated)
Fiber has dramatically reduced in our diet in the last few centuries. The caveman got 100-300 grams of fiber each day but we get around 12. The reason is that food with a lot of fiber is slow to cook and doesn’t store well. Fast food invariably has less than 1g of fiber per serving.
When Glucose enters the body, most of it is used up by cells and organs before it reaches the liver. What does enter the liver is easily stored there as Glycogen. When this happens the liver releases chemicals to signal to the brain that it should stop eating.
When Fructose enters the body, all of it reaches the liver where 30% of it gets turned into fat. Harmful chemicals are generated in the process. These chemicals can cause Gout and Hypertension, increase blood-pressure and suppress the signal to the brain that you should stop eating. (This part is hugely simplified. In the talk this is a long drawn-out discussion about the biochemistry of metabolizing Fructose)
Fructose metabolized in much the same way as alcohol, only it doesn’t affect the brain directly.
What to do to counteract obesity:
1. Stop consumption of all sugary drinks, including juices.
2. Always eat carbs with fiber. Fiber counteracts many of the negative aspects of Fructose and makes you feel full faster.
3. Wait 20 minutes before second portions.
4. Buy TV or computer time minute-for-minute with physical activity. (this doesn’t necessarily mean high-intensity exercise but can merely be doing the dishes, walking from work etc)
Exercise isn’t really about burning calories. It makes it easier for the body to tell you when to stop eating and helps it regulate blood sugars. It reduces stress and therefore appetite and it speeds up the metabolism, burning off chemicals before they get turned into fat.
The earlier you expose children to sweets, the more they will crave sugar later in life. This also goes for pregnant women and their unborn babies.
So why doesn’t the FDA regulate Fructose if it is this harmful? Apparently they only regulate toxins that have a harmful effect in a single dose, not those that need chronic exposure. So sugar is excluded.
Some points of criticism have already been included inline in parenthesis but additional points from “The bitter truth about fructose alarmism”, a rebuttal to the lecture, are included below.
One of Lustig’s main points is that when Fructose is consumed it does not send a signal to the brain to stop eating. However, when one eats anything sugared, the Fructose is always accompanied by (nearly) as much Glucose which DOES send such a signal to the brain.
Most of the effects Lustig claims Fructose has on appetite has only been shown in studies where Fructose was 30% or more of total calorie consumption, which is unreasonably high.
Like the effects of Ethanol, the effects of Fructose are doze-dependent.
Whether we define Fructose as a poison or not is largely irrelevant as it clearly has a negative impact on the body. Whether HFCS is worse than sugar is mostly irrelevant as well as neither should be consumed in large amounts.
Drinking sugared beverages comes with a load of problems and no visible benefits. Being neglectful enough to allow children to drink them daily has an enormous impact on their future health and odds of becoming obese. Remove them completely or at least cut them down to 1-2 drinks a week.
Regular exercise and enough fiber in our diet are two things we all know we should get and most of us still don’t get enough of. Clearly both have considerable health benefits.
It is convenient to point a finger at a single substance and claim that “all our problems arise from this” but focusing exclusively on Fructose is likely to be as useless as it was to focus exclusively on fat. Cutting down on Fructose is a good thing, but so is cutting down on fat and alcohol and smoking and giving up pornography.