The United States has been experiencing a well publicized epidemic of obesity. Currently, over fifty percent of Americans are overweight. This epidemic has been associated with at least a five-fold increase in the incidence of Diabetes. Not so well understood and not so well publicized is the fact that diabetes is just the tip of the iceberg of insulin and sugar problems in country. Today, over 25% of population has pre-diabetes also known as the metabolic syndrome or insulin resistance. While this syndrome was only described in 1989, it is responsible for the great majority of the weight gain of the western world and is responsible for over 50% of heart attacks and strokes. What is the cause of this epidemic and how can it be reversed?
The cause of the epidemic of obesity, diabetes and pre-diabetes were the low fat, high carbohydrate national diet recommendations which were made on the basis of wrong assumptions. The wrong assumptions were due to a lack of medical knowledge that fortunately is now available due to the forward march of research and technology. The misconceptions and lack of knowledge that lead to counterproductive recommendations were: 1) High total fat intake was primarily responsible for heart attacks and strokes; 2) The role of dietary fiber in our physiology was unknown until the last 10-20 years; 3) The effect of sugars vs. starches on our blood sugars and insulin levels was unappreciated until the 1980s; 4) The mechanism of how refined carbohydrates make us gain weight was not known until the late 1990s. 5) The differential effects of the various classes of fats were not appreciated until the late 1990s.
In the late 1960s, the carbs we adopted were not like the carbs of countries like China and Japan. Rather than whole grain rice, we adopted highly processed carbs such as instant rice, white bread and potatoes. These carbs are devoid of the fiber that was found in the high carb societies that were relatively free of obesity, heart attacks and strokes. In fact, more recent studies done at the Harvard School of Public Health has shown that fiber was more important than fat in causing heart disease. How do processed carbohydrates make us fat and what can we do about it?
We now know that processed carbohydrates that are rapidly digested and absorbed into our blood stream cause large swings in our blood sugars and in our blood insulin levels. To explain this concept to my patients, I use an analogy of alcohol ingestion with and without food. Alcohol is the one nutrient where we can monitor our own blood levels because of how we instantaneously feel. Drinking alcohol without food is like eating a starch such a white bread without fiber. Both move rapidly through the stomach and are absorbed into the blood stream. In the case of alcohol, we rapidly feel tipsy. In the case of white bread, we are in fact drunk with blood sugar though we cant feel it. The rapid rise in blood sugar results in a large pulse of insulin from our pancreas. This lowers and the blood sugar rapidly causing a phenomenon known as reactive hypoglycemia. This hypoglycemia often results in hunger, food cravings, fatigue, dizziness headaches and other unpleasant symptoms. We eat carbs rapidly to resolve these feelings. The problem is that we overeat in an attempt to feel better and unfortunately, this initiates another cycle of high blood sugars, insulin levels and hypoglycemia. This cycle leads to weight gain. It turns out that beer contains the sugar maltose which raises our blood sugars faster than any other nutrient. The resultant large swings in blood sugar leads to overeating consequently, the classic beer belly.
We all know that when we consume alcohol with food, we do not feel tipsy nearly as rapidly. This is because the food that mixes with the alcohol slows its digestion. This is analogous to eating whole grain bread, where the fiber has not been processed out. The digestive process must separate the starch from the fiber in the bread and this takes time. Thus, rather than getting drunk on starch, we get a much slower rise in blood sugar and insulin. This acts like a slow infusion of energy that avoids the reactive hypoglycemia that sends us rushing back to the refrigerator or cupboard. This is why our ancestors were not walking around with constant cravings and why obesity was rare in earlier times.
When we produce insulin in response to blood sugar elevations, its ability to lower our blood sugars vary from individual to individual. For those of us with insulin resistance, it takes a higher pulse of insulin to open the tissue locks that lets the blood sugar in. Higher pulses of insulin secretions cause greater drops in blood sugar and consequently more urgent symptoms of reactive hypoglycemia.
Dr. Arthur Agatston MD is a cardiologist who has served on committees of the American Societies of Echocardiology, the American College of Cardiology and the Society of Atherosclerosis Imaging, where he is a member of the founding board of directors. He lives in Miami Beach with his wife Sari and two children. He is author the new book, The South Beach Diet (Rodale Press; $24.95; 2003).