Between 1970 and 2010, the U.S. adult obesity rate increased from 12% to 35% and obesity became a major public health problem. Excess weight is responsible for our epidemic of diabetes and is a major contributor to heart disease and many other health problems. While the rate of increase has slowed since 1990, waistlines have continued to expand.
Many different and often contradictory theories have been advanced to explain this rapid increase in obesity starting in the mid-1970’s. As a result, no consensus exists about how to address the problem. I wish I could advocate a comprehensive program. The best I can do is offer a few suggestions based on my personal experience during the last four years.
Like most people, I started slowly gaining weight after I turned 30 years old. By the time I was 60, I was just crossing over into the “overweight” range on the BMI charts (I’m 5’ 11’’ tall and was then 183 pounds). The conventional diet advice—“reduce calories, exercise more, and cut fat from your diet”—never worked for more than a few days. I ended up concluding that evolution has strongly programmed us to resist going hungry and that I was doomed to get slowly fatter.
About five years ago, I read Gary Taubes’ book, Why We Get Fat and my views about diet and weight gain radically changed. Taubes makes a convincing case that weight gain is not due to eating too many calories or to exercising too little. It isn’t an energy balance problem. Weight gain is fundamentally a hormone problem caused by eating foods that simulate the production of too much insulin. Insulin is the hormone that signals the body to store fat.
I decided to give Taubes’ recommendations a try. I eliminated sugar, grains and white potatoes from my diet and ate as much as I wanted of everything else—adding nuts for snacks and more vegetables. I committed to never being hungry. I’d briefly tried similar diets before and wasn’t surprised when I lost five pounds during the first week. After about a week on the diet, I noticed an unexpected result—my chronic upset stomach disappeared and getting through the day no longer required taking 10 Tums. This discovery provided an additional incentive to eliminate grains and may be why I’ve stayed on the diet. Over the following month, my weight continued to drop. I lost a total of 17 pounds and ended up back at the weight I was in college. Before I tried my new diet, I believed winning a million dollars in the lottery much more likely than ever getting back to my college weight.
I started reading other books about diet’s effects on weight and health—including Taubes’ earlier magnum opus, Good Calories, Bad Calories. Taubes argues that the obesity epidemic started in the 1970’s as an unintended consequence of the campaign to convince the public to adopt a low-fat diet to prevent heart disease. The fat-cholesterol-heart disease link seemed plausible. Gooey fat is turned into gooey cholesterol by the body and this excess cholesterol plugs up the body’s plumbing. Unfortunately, the advice was never adequately tested and subsequent research has been unable to confirm the links. The food industry quickly responded by taking the fat out of processed food and substituting sugars—and the obesity epidemic was launched. Between 1970 and 2000, the amount of sugar in foods rose 25 percent.
The public now believes with almost a religious fervor that fat damages their health. This belief is why many pages of Taubes’ books on obesity are devoted to examining the scientific links between fat and heart disease. I recently finished Nina Teicholz’s new book, The Big Fat Surprise. Most of the 300 pages are devoted to a critical re-examination of the scientific studies about fat. In the end, she comes to the same conclusion as Taubes—refined carbohydrates, not saturated fats, are the main cause of obesity and heart disease.
My suggestions to curbing obesity:
1. Progress won’t be made until our “public health experts” start advocating a clear new message. The previous advice—cut calories, exercise more, and eat a low-fat diet—doesn’t work. The best way (probably the only way) to attack obesity is to change the type of foods eaten by eliminating (or dramatically reducing) sugar and other refined carbohydrates.
I’ve been surprised by how difficult this change seems to be for most people—especially since the diet doesn’t requires going hungry. Refined carbs evidently are very addictive and a month on the new diet may be required before the craving for refined carbs starts to abate.
2. We need to stimulate a renewed interest in cooking. Most processed foods are full of refined carbohydrates and a healthy diet requires more time in the kitchen chopping vegetables!
3. Exposure to farmers markets and local fruits and vegetable farms should be a part of the curriculum in every school. Students should learn to value fresh foods and know how to cook them.
Reading the history of the diet wars over the last fifty years has led me to two conclusions. First, the advice we’ve received from our public health “experts” about what constitutes a healthy diet has been systematically wrong. It has caused great damage. Second, be very skeptical about everything you read about diet—including what I am writing in this blog. Testing theories in a statistically valid way is very difficult because researchers can’t control what people eat over a long enough period to measure the diet’s effects on health. Wrong theories and radically different policy advice can persist for decades.