This is a very important lecture by Robert Lustig MD of UCSF Medical School which will scientifically debunk a significant majority of the last 30 years of nutritional information related to diets, weight loss, and obesity. Even though the audience is primarily medical professionals, the science lecture is very entertaining and informative for all interested in weight loss and detoxification. In my opinion all parents must watch this lecture for the benefit of their children.
He explains why some diets work and why many don’t. It is not a matter of “LOW CARB” or “LOW FAT”. The real culprits are sugars, either in the form of processed sucrose, like table sugar, or processed fructose, like high fructose corn syrup.
You should also know that this sucrose and fructose is commonly found in most processed food at the grocery store like breads, pastas, canned items, condiments, yogurt, sauces, cereals and protein bars. So when we talk about sugar below, we mean any and all sucrose and fructose.
Yes, fructose is bad too. In nature, fructose found in fruit is always provided with excess amounts of fiber which reduces the rate of intestinal absorption of the sugar. So while it is recommended to eat a whole orange or apple, remember orange juice or apple juice are bad.
Regular dieticians will tell you a “calorie is a calorie”. This is false. Calories from sugars are more harmful because of the way your body will metabolize them. These calories from sugars should be eliminated from your diet. Calories from sugar may be “isocaloric” BUT NOT “isometabolic” with calories from glucose.
Sugars also put a burden on the liver like alcohol. Anyone wishing to detoxify or with a chronic illness must remove this burden from their immune system. He goes on to discuss the toxicity of sugar.
Main points from video :
Sugar (either as sucrose or fructose) is NOT the same as glucose. Skeptics should hold their commentary till they watch the biochemistry slides.
Sugar disrupts leptin and ghrelin, two hormones that signal satiety in the brain thereby reducing your hunger, and in effect causes you to consume more unneeded calories.
Sugar increases insulin in the blood which triggers hunger.
Sugar is technically a chronic liver poison because it cannot be properly metabolized and eliminated by your liver, unlike glucose that can. Sugar is metabolized similar to the toxin alcohol.
Sugar consumption, biochemically, is the equivalent of fat consumption. A high sugar diet is a high fat diet because of de novo lipogenesis. The sugar is converted to fat.
Sugar causes inflammation in the body. I’ll write more about inflammation in another article, later.
Sugar also contributes to Heart Disease, Diabetes (Metabolic Syndrome):
- Sugar will increase the small dense fat (bad fat) in your blood LDL(b).
- Sugar will increase your triglycerides the same as alcohol.
- Sugar will increase your blood pressure by blocking nitric oxide.
What can I do?
1. Read Labels
Read the food label to look for hidden sugar. Don’t be misled by labels like “all natural”, “fat free”, “100% juice” or “whole grain”. Look for the labeled sugar content that is usually given in grams, which is a unit of weight. Divide the number found on the label by 4 to get the number of teaspoons of granulated sugar. For example, a 12oz. soda contains 44g of sugar, which is 11 teaspoons! Finally, read this link on how to understand the Nutritional Facts Label.
Get rid of all sugared liquids including sodas and juices. Keep only water and milk in the house.
Of course the regular sugar culprits should be avoided like sodas, cakes, candy, and obviously sweet foods.
A proper eating plan should include healthy fats, complex carbs, complete proteins, low sodium, low sugar and adequate fiber.
2. The real benefits of exercise:
Exercise improves skeletal muscle insulin sensitivity. Your body will produce less insulin which is a good thing.Exercise reduces stress and the resultant cortisol release, thereby reducing your appetite and also conversion of sugar to fat.
Exercise “speeds your metabolism”. By this we mean the sucrose or fructose is burned before it hits the liver and is converted to fat.
Exercise may lead to increased muscle mass which then increases the number of calories you burn at rest!
The calories burned at the time of exercise is trivial. For example, you would need to run 20 minutes to burn the calories from one chocolate chip cookie.
3. Take Fiber with sugar and other carbohydrates.
Fiber reduces the rate of intestinal carbohydrate (and sugar) absorption, thereby reducing insulin response. Basically, some of the calories are being passed through your system. Remember many starches in your diet are quickly converted into glucose and then fat.
Fiber increases the speed of intestinal contents. The satiety hormone signals are triggered faster, so you eat less. Wait 20 minutes for seconds.
Fiber increases the production of short chain fatty acids (SCFA) by the colon which suppress insulin.
NY Times Magazine Article, by Gary Taubes, “Is Sugar Toxic?” Expands on Dr. Lustig’s lecture but also importantly brings up the link between diabetes and cancer, which is only recently is getting more attention. I’ll write more about this later.
NPR Madeleine Brand Show, Audio Interview with Gary Taubes