Monday, December 01, 2014
Don't Spike Your Blood Sugar
There have been a number of scientific papers in the last couple years, and now a number of high-profile articles (like last week's Time Magazine article "Ending the War on Fat") that have found no correlation between fat -- even saturated fat -- and Alzheimer's, diabetes, cancer, or heart disease. The idea that cholesterol and saturated fat are the cause of heart disease is no longer supported by the best available science.
However, there is still broad consensus among health professionals that we need to avoid processed, sugary, and high-glycemic foods. High-glycemic foods are energizing for an hour or two but then cause sleepiness and craving for more (usually high-glycemic) snack foods. These foods are dangerous because they raise blood sugar, leading to a crash afterwards, a "roller-coaster" blood sugar dynamic that promotes over-eating and a variety of diseases.
Gary Taubes, in Good Caloreis Bad Calories, explains how sugar metabolism makes you fat:
"Glycerol phosphate is produced from glucose when it is used for fuel in the fat calls and the liver, and it, too, can be burned as fuel in the cells. But glycerol phosphate is also an essential component of the process that binds three fatty acids into a triglyceride. It provides the glycerol molecule that links the fatty acids together. In other words, a product of carbohydrate metabolism --i.e. burning glucose for fuel-- is an essential component in the regulation of fat metabolism: storing fat in the fat tissue. In fact, the rate at which fatty acids are assembled into triglycerides, and so the rate at which fat accumulates in the fat tissue, depend primarily on the availability of glycerol phosphate. The more glucose that is transported into the fat cells and used to generate energy, the more glycerol phosphate will be produced. The the more glycerol phosphate produced, the more fatty acids will be assembled into triglycerides. Thus, anything that works to transport more glucose in the fat cells -- insulin, for example or rising blood sugar, will lead to the conversion of more fatty acids into triglycerides, and the storage of more calories as fat."
"So yes, dietary fat is responsible for fat accumulation, but it is carbohydrates that mediate the accumulation, and the energy balance of the body as a whole. Don't spike your blood sugar, and your body will continue burning fat, not storing it."