08 December 2013

VIDEO: Dr Jeff Volek about Low-Carb Diet

This is a video about going from a high-carbohydrate to a low-carbohydrate diet. Here are a few notes:
"Sweden has become the first Western nation to develop national dietary guidelines that reject the popular low-fat diet dogma in favor of low-carb high-fat nutrition advice."
Obesity rates are increasing in the US. Unfortunately, exercise has not been proven to be the ideal solution for weight loss. Exercise is very important for overall health, but it does not work for everyone when it comes to burning fat tissue. 

Obviously, we are all different and we tolerate different amounts of carbohydrates. Some people do well on a high-carb diet. The problem appears when people start to gain weight. It is not a problem of calories in (eating) versus calories out (exercise). It is a problem of fat storage. Why are certain people storing energy in their fat tissues? To answer this question, we need to see which hormone regulates fat tissue. It is regulated by insulin. The higher the insulin levels, the more energy goes to storage.

During the majority of human history, we were not exposed to the amounts and refinement of carbohydrates available today. Honey is protected by bees, fruits and grains are packaged with fiber (which slows down absorption). Refined carbohydrates and sugar were hard to come by. Today, with the help of technology, these types of food are available 24/7.

Protein and fat consumption, since the 1970s, remains pretty stable to this day. However, carbohydrate consumption increased substantially, and not in the form of more celery and kale greens, but in the form of Mars bars, Coke etc.

In the video at 15.45, there is a good example of how much sugar we have in our blood at a given moment:
  • Normally, we have 2 teaspoons of sugar dissolved in our bloodstream (about 8 grams)
  • When we gobble up a Starbucks bagel and a Latte, we end up with 75 grams of sugar in our system. Almost 10 times more the normal amount.
When a healthy person ingests carbohydrates, these will be burned in the muscle. However, when a person is insulin resistant (muscle tissue not able to burn carbohydrate as fuel) and/or overweight, the majority of the carbohydrates goes to the liver where it will be transformed to fat and shipped out of the liver into the blood in big VLDL balloons (see my post on Cholesterol). The more carbohydrate one consumes, the more fat appears in the bloodstream (this is not true for dietary fat). 

This condition could be called as "carbohydrate intolerance". When we are lactose intolerant, we reduce our dairy consumption. A similar behavior should be applied when we are carbohydrate intolerant: we should restrict carbohydrates until a tolerable level. 
"Diabetes = Side effect of consuming too much carbohydrate relative to a person's tolerance."
This means that some people tolerate carbohydrate very well. But, if people become obese, insulin resistant or diabetic, it means that they have reached their level of tolerance. 

At 20.50, he compares the weight-loss results of a low-carbohydrate diet (Atkins type) versus a low-fat diet (Ornish-diet), and also compares two kinds of people: healthy (insulin sensitive) versus insulin resistant individuals.

On the low-carbohydrate (high-fat) diet, the weight loss results were very similar: 
  • 11.9 lbs of weight loss for insulin resistant patients
  • 11.7 lbs of weight loss for insulin sensitive (healthy) persons
In the case of the low-fat (high-carbohydrate) diet the results are quite different:
  • 3.3 lbs of weight loss for insulin resistant patients
  • 9.0 lbs of weight loss for insulin sensitive (healthy) persons
This means that a low-fat diet recommended by the majority of health authorities worldwide, do not seem to perform as well as a high-fat diet, especially in the case of insulin resistant persons. This seems to confirm the theory about the limits of carbohydrate tolerance.

For these insulin resistant patients, the ideal would be to switch from a carbohydrate metabolism (burning carbohydrate for fuel) to fat metabolism (burning fat for energy).

When carbohydrate is not available, we take energy from ketone bodies and fatty acids (I already wrote about ketogenic diet briefly). This type of metabolism seems to be associated with health and longevity. Cancer cells thrive in a high-glucose (high-sugar) environment. But, when the body's metabolism is switched from glucose-burning to fat-burning, tumor usually shrinks. Cancer cells have not the ability to survive without sugar.

Oxidative stress is also reduced in a low-glucose environment, cell damage happens at a slower pace. This implies that the need for antioxidants is also reduced. Today, it is quite widespread to take antioxidant tablets to prevent cell damage. But, the reduction of carbohydrates seems to have a similar - if not more powerful - effect in preserving our cells. Fat metabolism is like an anti-aging recipe.

Interesting graph at 25.10, "Eating carbohydrate locks you in a glucose-dependent metabolism". When we eat sugar, our blood glucose level rise, as a result our pancreas secretes insulin to take out the overload of glucose. Subsequently, glucose levels go below normal, making us feel tired and lethargic. To compensate we eat more sugar to bring back our glucose levels to normal. And this goes on.

The human body is cleverly constructed: if both fat and glucose are present in our bodies, the primary fuel will be glucose, as high glucose levels are dangerous. So the body works on removing glucose from the bloodstream, either by burning it or by releasing insulin, and storing this valuable fuel in the fat tissue, resulting in weight gain.

When there is no glucose to be burnt for fuel, fat will be our source of energy (fat metabolism). This function is dormant in the presence of glucose. The only way to unleash it, is by restricting carbohydrates, this also leads to the production of ketone bodies:

At 32.20: The protective effects of ketone bodies:
  • "Clean burning fuel"
  • Less generation of reactive oxygen species (ROS)
  • Increased antioxidant effect
  • Greater efficiency in providing cellular energy
  • Increase in work output, while a decrease in oxygen consumption.
Very interesting to see the difference between a low-fat and a low-carbohydrates diet (at 35.25). A low-carbohydrate diet seems to perform better than a low-fat diet on the biomarkers associated with metabolic syndrome (insulin resistance).

A low-carbohydrate diet also reduces pro-inflammatory markers. So less inflammation in the body (37.00).

(37.07) The consumption of saturated fat is not associated with heart disease. However, (38.42) elevated saturated fat in the blood is a predictor of heart disease, diabetes and metabolic syndrome. It turns out that the consumption of carbohydrate lead to more blood lipid (fat) and consuming fat, leads to a reduction in blood lipid levels.

Look at the table at 40.25 and see what happens when you eat your steak with potato versus with green vegetables. The result is very different.

42.23: The adoption of a ketogenic diet shows improvement in:
  • diabetes
  • cancer
  • neurodegenerative diseases such as epilepsy, Alzheimer's, depression etc.
50.00: What to eat, a few ideas.

End of the presentation with this quote:
"Half of what we know is wrong, the purpose of science is to determine which half."
                                                        - Arthur Kornberg


  1. I finally got around to watching this video last night - excellent. I found Dr Volek's presentation easy to follow and I actually learned something! Thanks.

    1. Most welcome! It's a great presentation.

  2. Great presentation Dr.Volek!.Last month I had attended a weight loss exercise program conducted at Ontario .Now I can very well relate this to the program I attended.The major fuel burning behind weight loss is a man's desire and determination to achieve it !