My coworker shared with me Sugar: The Bitter Truth, a UCSF talk given by Robert H. Lustig, M.D. His presentation covers and gave me a better scientific understanding of the many nutritional issues I am interested in. My top five favorite topics covered are as follows:
- A calorie is not a calorie.
- The real problem with high fructose corn syrup (HFCS).
- Low-density lipoprotein (LDL) measurements are not as significant as we are led to believe.
- Ancel Keys’s Seven Countries Study.
- The importance of exercise.
1. A calorie is not a calorie.
While I instinctively believed that a calorie is not a calorie (i.e., 100 calories of chocolate is not the same as 100 calories of broccoli), I had no solid scientific information to support my belief. In his presentation, Dr. Lustig compares what your body does with 120 calories of glucose, ethanol, and fructose.
When consuming glucose, almost none of it ends up stored as fat, as opposed to fructose where 30% is stored as fat. The main takeaway is that the human body responds differently to different types of food, which is especially important when addressing fat storage.
2. The real problem with high fructose corn syrup (HFCS).
High fructose corn syrup is a one glucose molecule bonded to one fructose molecule, and it is sweeter than regular sucrose (standard sugar). The hunger and satiety profiles are the same for both HFCS and sucrose. The problem is that HFCS is significantly cheaper than sugar and is now used as a preserving agent and sweetener in almost all processed foods. The result is that the American public is unknowingly consuming significantly more sugar than before HFCS was introduced.
3. Low-density lipoprotein (LDL) measurements are not as significant as we are led to believe.
There are actually two types of LDLs: Pattern A and Pattern B. Pattern A LDLs cannot start plaque formation, while Pattern B LDLs can. LDL measurements are misleading because they measure both types of LDLs at the same time. What you really want to look for is a low triglyceride and a high High-density lipoprotein (HDL) measurement, which is good. Conversely, a high triglyceride and low HDL is bad.
4. Ancel Keys’s Seven Countries Study.
Ancel Keys is famous for his Seven Countries Study, which concluded that fat consumption causes cardiovascular disease. This conclusion is what 30 years of nutrition education and policy is based on. According to Dr. Lustig, Keys’s data analyses were flawed. When taking a closer look at the study, sugar increased with fat, which means that fat was not the only correlating factor. This flaw explains why American’s war against fat has not decreased the incidence of cardiovascular disease or other health issues.
5. The importance of exercise.
Exercise is not important because it burns calories. It is important because it improves skeletal muscle insulin sensitivity, thereby decreasing insulin levels. In addition, exercise reduces stress, which reduces appetite. Lastly, it makes the TCA cycle run faster, so citrate does not leave mitochondria and is not converted into fat.