The public’s almost insatiable appetite for information about diet and health has led to an explosion of articles, books, websites, blogs, and documentaries.  While I think more information is almost always better, it is becoming increasingly difficult for many people to sort out good and evidence-based information from storytelling and fiction.  Unfortunately, it appears to be equally difficult for some health professionals to tell the difference too.  This seems to be the case with Wheat Belly, a book written by a medical doctor and which has been endorsed by many doctors and other health providers.

Due to the popularity of this book, we receive a lot of inquiries about it. So we decided that it was time to perform a detailed analysis of the book. In order to do this, we first charged an intern with looking up and archiving all of Davis’ citations so that we could compare them to the statements he makes in the book.  Our intern was able to locate all but three of the listed citations. We then read the book and created two 2-hour workshops with accompanying slides in which we addressed each of Davis’ claims and the citations he used to support them.  When there was no supporting evidence offered, we noted that as well.

In this article, I’ll highlight the major conclusions of our analysis. Space limitations require that I only cover the main points, so if you are interested in more information, you can watch the lectures online and read the accompanying detailed powerpoints, which include our own references that refute Davis’ claims.

I’ll start by saying that this is perhaps the worst book about diet and health I’ve ever read.  Davis starts by saying that people would lose weight and their health would improve if they ate less or eliminated processed foods.  This is true.  But everything that follows after that is either pure fantasy or a gross misrepresentation of the little evidence offered in support of Davis’ claims. Many of Davis’ citations have nothing to do with his statements, and some actually report conclusions that are contrary to what he says.  Some of the studies do not even mention the words “wheat” or “grains.” (we used the search function to scan the entire text of the studies to confirm this).  There are many statements that contradict one another and some of the contradictions occur on the same page.

Here are a few of the highlights:

  • Davis claims that one of the problems with wheat is that it has been hybridized. This is true, and is also the case with every other food we consume.  Hybridization has been used since the beginning of agriculture and without it there would be very little to eat.  In fact, had Irish farmers used hybridization to develop a variety of potatoes, there would have been considerably less starvation or perhaps no Irish potato famine. But since there was little diversity in the potato crop, almost all of the country’s potatoes were wiped out by blight, which caused mass starvation throughout the country. Davis does not warn his readers to stay away from any other commonly hybridized foods, like grapefruit, tomatoes, beets, carrots, corn, cucumbers, eggplant, spinach, squash, and broccoli.  He says it’s only hybridized wheat that is a problem.
  • Davis always refers to junk foods when advising against eating wheat wheat and grain products. Throughout the book as he recommends eliminating wheat and grains, Davis includes lists of grain-containing foods such as Lucky Charms, Oreo cookies, Trix, Fruit Loops, Fettuccini Alfredo, Scooter Pies, and Vienna Fingers as examples of foods we should stop eating. Apparently he is unaware of the fact that people can include foods like wheat berries, faro, millet, and whole wheat pasta as part of a healthy diet.  Perhaps he should have called his book Junk Food Belly, which would have been more appropriate if he intended to caution people about eating highly processed foods.
  • Davis claims that Americans have tried low-fat eating and exercising and it does not work. He claims that all of his patients were eating a low-fat diet and exercising  for an hour per day and they were still unable to lose weight or get well until they stopped eating wheat.  Evidence shows that contrary to Davis’ claims, calorie and fat intake have increased, not decreased in the S.  At the same time exercise and even the amount of movement required for daily life has decreased. Since Davis does not provide even one well-written case study in his book, I cannot refute his statement that all of his patients were eating well and exercising a lot when they arrived in his office. I’ll just say that his claims are hard to believe. I, along with several of my colleagues, would like to know how to find these diligent patients who do everything right.
  • Davis says that as wheat intake has increased, so has the incidence of many diseases. Davis provides no references for his claim that wheat intake has increased. But published data show that wheat intake has actually decreased since the 1800’s. Wheat intake hit a high of 225 pounds per year in the 1880’s, dropped to about 110 pounds per person in 1980, increased to an average of 146.3 pounds in 2000, and has been dropping ever since.  So the accurate statement would be, “As wheat intake has decreased, health problems have increased.”
  • Davis advises against wheat because it is a high-glycemic food.  Using glycemic index as a means for choosing foods would result in eating ice cream (51) instead of whole wheat bread (129), sugar-sweetened chocolate (49) instead of carrots (131);,and Mars candy bars (97), instead of baked potatoes (134).
  • Davis advises against eating wheat because, he claims, wheat is high in advanced glycation end products (AGE’s) which increase the risk of disease and accelerate aging. Wheat and grain products are actually low-AGE foods.  Even highly processed foods like white bread (7) and Frosted Mini-Wheats (63) are low-AGE foods. But more importantly, many of the foods that Davis heartily recommends that people include in their diets like olive oil (11,040) and beef (7479) contain incredibly high amounts of AGE’s. In one chapter, people are warned about the dangers of eating foods high in AGE’s and later in the book they are encouraged to eat as much as they want of high-AGE foods. The book is filled with these types of inconsistencies.
  • Perhaps the most egregious misrepresentation in the book is Davis’ frequent use of studies showing that celiac patients get better when they adopt a medically gluten-free diet as a reason for members of the general public to eliminate wheat. Davis says that studies show that people experience weight loss and health improvement when they eliminate wheat. In some cases, Davis provides a citation for these statements, but almost all of the citations are studies reporting that celiac patients showed health improvement after adopting a medically gluten-free diet.  These patients did not just eliminate wheat, but rather eliminated ALL gluten from the diet, and they were afflicted with a disease that required them to do so in order to get well. Davis also cites studies showing that when celiac patients are not compliant with gluten elimination, they get sick.  But in the text he reports that everyday people who eliminate wheat get well and that when they reintroduce wheat into their diets they get sick, and cites studies of celiac patients to support his statements.  Is Davis so incompetent that he does not know that celiac patients must eliminate all gluten, not just wheat; or that there is a difference between celiac patients and people who do not have celiac disease?  Or did he intend to deceive his readers, hoping that no one would actually read the citations and see that the studies don’t support his claims?  I’m frankly disturbed by either possibility.
  • Davis says that celiac disease is an example of how bad wheat is for humans. First, this is a ridiculous statement, which is akin to saying that people who experience anaphylactic shock as a result of eating nuts are an example of how bad nuts are for all humans. But his misrepresentation is even bigger. Celiac patients do not have a reaction to wheat, but rather a reaction to ALL gluten. As a medical doctor he should know this, but he specifically states that celiac patients have to eliminate wheat to get better several times in the book.
  • Davis makes unsubstantiated health claims about the benefits of wheat elimination. Sprinkled throughout the book are stories about patients who were eating ideal diets that included wheat while exercising an hour per day, but gaining weight and getting sicker anyway. After conversion to a wheat-free diet, they lost weight easily and all of their diseases were quickly resolved. No evidence is offered; as mentioned earlier, there were not even any well-written case reports to substantiate the claims. But by the end of the book, Davis has claimed, through patient stories, incorrectly cited reports of studies about celiac patients, and unsubstantiated statements, that people who eliminate wheat can expect to lose weight without any other dietary changes, to have flat stomachs, to have lower blood pressure and cholesterol; and to recover from conditions like rheumatoid arthritis, asthma, insomnia, low sex drive, acne,  low energy, cognitive decline, depression, anxiety, schizophrenia, and almost every other physical or mental disorder.
  • In one of the most memorable parts of the book, Davis relates the story of a study he conducted on himself which may help to explain the inconsistencies and inaccuracies in the book.  After a long diatribe about how wheat has changed from an ancient grain through hybridization, he states that while ancient grains may be better, they are hard to find. In fact, he says, one has to visit places like southern Italy or the Middle East to look for grains like einkorn. On the next page, he reports calling a toll-free number in the U.S. to order some einkorn. He then ate 4 ounces of bread made from einkorn one day, and had no symptoms after the meal. The next day, he ate 4 ounces of bread made with conventional wheat, after which his symptoms included “nausea, fitful sleep with vivid dreams, loss of concentration, and difficulty reading research papers.”   Perhaps Davis never recovered from this single episode of wheat eating and has remained so damaged that he cannot read, understand, and accurately report research findings.

But this does not explain why medical doctors and other health professionals have embraced Davis’ ideas.  Possible explanations include failure to look up the citations and compare them to the statements made, an inability to understand the studies cited, willingness to adopt any new dietary theory without investigation, and/or failure to notice the numerous inconsistencies throughout the book. Any of these explanations are disturbing, and should motivate patients to carefully consider recommendations from medical professionals and to do their own research before acting on them.