Severely restrictive diets — of any type — may backfire in the end

For overweight individuals, the Greek physician Hippocrates advised a regimen of exercise and vomiting. Around 1080 C.E., William the Conqueror suggested a diet of drinking alcohol. In the 1800s, Lord Byron followed a vinegar diet.

In the early 1900s, the tapeworm diet was advocated. (The idea was that the tapeworm would consume your food, and later the tapeworm would be expelled.) The 2013 cotton ball diet staunched hunger, but it was abandoned after dieters developed intestinal obstructions and sometimes died.

Other diets that have lost their appeal include the grapefruit diet, Scarsdale diet, cigarette diet, cabbage soup diet and the SlimFast diet. The vegetarian, vegan and raw food diets originated in the 1800s, and the keto diet goes back to the 1920s.

Daniel J. Levitin gives the rundown on all of these diets in his 2020 book, “Successful Aging: A Neuroscientist Explores the Power and Potential of Our Lives.” If one diet were “clearly superior to the others,” he writes, “after all this time we’d know about it.” 

The stakes are high for Americans to find a safe dietary solution that works. According to the U.S. Department of Agriculture, 74% of adults are overweight or obese.

An observational study published in JAMA in 2005 compared the four leading diets at the time: Ornish, Atkins, Zone and Weight Watchers. After one year, there was very little difference regarding weight loss or cardiovascular risk factors. Dietary adherence was low, but the greater the adherence, the better the weight loss and cardiovascular risk-factor results.

What these findings suggest is that following any particular diet makes us cognizant of the kind and quantity of food we consume and perhaps compels us to become more interested in other beneficial health behaviors.

Social media and many diet books encourage extreme carbohydrate restriction. This type of diet is contrary to the recommendations of the USDA’s current dietary guidelines. As Levitin states, “There is no scientific consensus that extreme carbohydrate restriction is helpful.”

Dr. Robert C. Atkins, who promoted a high protein, high fat and low carb diet, died at 72 in 2003 after falling and hitting his head. The Wall Street Journal and New York Times discovered that he’d previously had a heart attack, congestive heart failure and hypertension and weighed 258 pounds at the time of his death. Dr. Neal Bernard, president of the Physicians Committee for Responsible Medicine, later called the Atkins diet an “imminent public health threat.”

Another popular diet is the gluten-free one. Only about 1% of Americans have celiac disease, an immune reaction to gluten, but many more chose to avoid gluten.  Are you better off avoiding gluten even if you don’t have celiac disease?

Sophie Egan, author of the book “How to Be a Conscious Eater: Making Food Choices That Are Good for You, Others, and the Planet,” doesn’t think so. She points out that gluten provides strength and elasticity to dough. But when flour is substituted with tapioca starch and rice starch, the “thing being subbed in may actually be worse for you nutritionally than the thing originally deemed to be bad.”

After the publication of “Wheat Belly” by William Davis in 2011 and “Grain Brain” by Dr. David Perlmutter in 2013, Egan explained, hordes of people began following gluten-free diets. A 2013 survey found that 65% of Americans thought that gluten-free foods were healthier.

However, a 2019 study in the Journal of Nutritional Metabolism reported that gluten-free foods, when compared with equivalent wheat-based foods, show deficiencies in both minerals, including calcium, iron, magnesium and zinc, and vitamins, including B12, folate and vitamin D, as well as “significantly reduced fiber.” For those who eat processed gluten-free foods, this study raises concern.

Here is Levitin’s summary of what he considers common-sense principles for losing and controlling your weight:

  • Try to eat when you are hungry. 
  • Try to stop when you’re not hungry.
  • Seek to cope with emotions in ways other than eating. 
  • Don’t restrict the types of food you eat unless it’s for medical reasons.

Bon appétit!

Dr. Jerry Saliman

Jerry Saliman, MD, retired from Kaiser South San Francisco after a 30-year career and is now a volunteer internist at Samaritan House Medical Clinic in San Mateo.