The Obesity Epidemic: What Caused It? How Can We Stop It?
By Zoë Harcombe, BA, MA
Columbus Publishing, 2010
Near the start of this book we see a list of very good questions relating to the topic of obesity: Does energy in equal energy out? Do the laws of thermodynamics apply to humans? Where does the formula “one pound equals thirty-five hundred calories” come from? Are obese people always greedy or lazy or both? Can you prove saturated fat causes heart disease? How does exercise relate to weight loss or gain?
There are other good questions, and their answers may surprise a lot of people. To answer the first two questions in the list above, Harcombe untangles some widespread misinformation about the first law of thermodynamics. That first law does not say energy in must equal energy out. It says that energy in a closed system at thermal equilibrium is neither created nor destroyed. Energy can be transformed. Is the human body a closed system? No. So anytime you see “energy in equals energy out” in an obesity discussion, you are seeing a misapplication and misinterpretation of the laws of thermodynamics. It may look impressive to the uneducated, but it is incorrect.
Where does the formula “one pound equals thrity-five hundred calories” come from? Harcombe went to significant effort to trace that notion back to its origin. She researched the studies. She checked with all the major expert organizations in Britain, including the British Dietetic Association and the Department of Health. The straightest answer she got was, “We don’t know,” and it went down hill from there. It turns out that no one even knows exactly how the formula is calculated. The closest approximation Harcombe could come up with assumes there are 9 calories per gram of fat. One pound of fat would be 454 grams. Human adipose tissue is approximately 87 percent lipids, so 87 percent of 454 is 395. Multiply 395 grams by 9 calories per gram and you get 3555 calories. This equation is further muddied by the fact that 9 calories per gram is merely an estimate. Scientific experiments have measured anywhere from 8.7 to 9.5 calories per gram. When multiplied out, the answer lies somewhere between 3436 and 3752 calories per pound (in fat round numbers). The difference between those numbers is 316.
If you enjoy all this math, there is even more in the book for you to pig out on. If your head is starting to hurt from the math, there is a reason why I’m doing this to you. The experts like to use this equation as if it is an advanced, high-precision tool that will tell you exactly how many calories you need to deprive yourself of to lose a given amount of weight per week, month, or year. But if the equation is off by 316 calories per pound, when you start multiplying that out over one year, your results may vary by many pounds. One implication is that if your calorie balance is off by even a few jelly beans you will either waste away in a few years or bloat up so large you block out the sun. We have to admit that this equation is profoundly unhelpful.
This approach to calorie counting and weight control was put to the test in the Minnesota Starvation Experiment done in the 1940s. Thirty-six fit, healthy men were the test subjects, and the goal was to reduce their weight by 25 percent in 24 weeks. The experiment started with a control period to determine how many calories were needed to maintain a stable weight at a specific activity level. During the starvation period the test subjects were fed 1640 fewer calories while trying to maintain the same activity level. When weight loss did not meet the goal, their calorie allowance was reduced even further. According to the formulas promoted by the experts, each man should have lost at least 78 pounds, not including water. Actual loses were around 37 pounds and by week twenty they all reached a plateau and no further weight loss could be induced.
These men were miserable. They were constantly starved, depressed and weak. Some literally contemplated gnawing on their own fingers. Several cheated and were kicked out of the study. Once allowed to eat as much as they wanted again, they all quickly regained the weight and put on more. They couldn’t get enough food. Even when they were stuffed, they were still hungry and wanted more. None of them had any eating disorders or obsessions before the experiment. It became clear that no one could tolerate extended calorie deprivation outside of captivity.
Numerous contradictions in dietary advice are pointed out in the book. The Dietary Guidelines for Americans published jointly by the HHS (Health and Human Services) and USDA has many recommendations concerning carbohydrates. Two of them are: choose fiber-rich fruits, vegetables, and whole grains often; and reduce the incidence of dental caries by practicing good oral hygiene and consuming sugar- and starch-containing foods and beverages less frequently. One says eat starch often, another says don’t eat starch often. With advice like that, what could possibly go wrong?
Why are we getting so much bad advice? Harcombe takes a hard look at conflict of interest. The American Dietetic Association (ADA) is a dominant force on the American nutrition scene. It has succeeded in making it illegal in many states to give out nutrition advice unless you are certified by the ADA. A look at the partners and sponsors of the ADA and how much money they put up is very interesting. A very partial list includes Coca-Cola ($31.4 billion), PepsiCo ($44.3 billion), GlaxoSmithKline ($45.2 billion), General Mills ($14.9 billion), SoyJoy ($9.2 billion), Mars ($30 billion) and many others. Even I don’t want to do the math to add up all those billions. Maybe on the planet Pollyanna that is not a problem, but on this planet it is.
Many people believe exercise is the path to freedom from obesity. How does this belief measure up to the facts? According to the American College of Sports Medicine, “It is reasonable to assume that persons with relatively high daily energy expenditures would be less likely to gain weight over time, compared to those who have low energy expenditures. So far, data to support this hypothesis are not particularly compelling.” Our exercise hypothesis is not off to a good start. One study cited in the book indicated that the activity level of the average American went up in the period from the 1970s to early 2000s. Weight also went up during that same period. One more bullet: obesity in six-month-old babies is also increasing. Do we have an epidemic of laziness in babies?
In thirty seconds you can consume the same amount of calories as you would burn by running for hours. Doing the stairclimber while watching TV will most likely result in more weight loss between the ears than anyplace else, especially if it is daytime TV.
Harcombe doesn’t go into tremendous detail about solutions but nicely sums up the best solution, the solution that worked 99 percent of the time at least until 1980. Get off the grain-based, fat-building regimen and eat real food. Real food is the food that doesn’t have ingredients on the labels. You will also need to make those politically incorrect animal foods a significant part of your diet to get the nutrition you need. Another contradiction Harcombe points out in the USDA food pyramid advice is the impossibility of getting all of the recommended nutrition in a grain-based diet without far exceeding the recommended calories.
Our obsession with calories is a monumental waste of time. Zoë Harcombe is logically, mathematically and scientifically ruthless in blasting through the fog of urban legends that surround the subject of obesity. Yet her book is not at all hysterical in tone. With almost dispassionate aplomb she shreds, slices, dices and purées the expert advice, the equations and the superstitions. That’ll get my thumb up any day.
This article appeared in Wise Traditions in Food, Farming and the Healing Arts, the quarterly magazine of the Weston A. Price Foundation, Winter 2010.