The Whole30 diet, a version of an elimination diet, has been gaining steam. Described by its co-author Melissa Hartwig as a “short-term reset”, the philosophy behind this diet is to eliminate certain foods for 30 days. By doing this, the theory is that individuals will not only feel better but will also have a more positive relationship with food. But, do these claims hold water?
Recently, U.S. News & World Report published their annual rankings of the “Best and Worst Diets.” According to their team of experts, the Whole30 diet ranked last on their list. Their reasoning: the diet is simply too restrictive. A number of well-designed studies have found that restrictive diets often do not lead to long-term change. The intention of the Whole30 diet is to follow their published guidelines for 30 days. But, does following this meal pattern actually lead to lifestyle change? There are no published data to support this.
Hartwig states,“Our program's efficacy speaks for itself, as evidenced by the countless medical doctors who successfully use our program with their patients, and the hundreds of thousands of life-changing testimonials we've received.” However, these are examples of anecdotal evidence and as a result, cannot be taken too seriously. We need well-designed studies to see if these health effects occur because of the diet or due to other factors entirely. For example, when deprived of many of the foods we enjoy, daily calorie intake will likely decrease, which will lead to weight loss which may lead to reported improvements in mood, blood sugar, etc. So, we need to ask whether weight loss is the reason individuals feel better when following the Whole30 diet, or whether it is the elimination of specific foods. We will only know through well-designed research studies.
The evidence regarding the diet’s ability to heal is also sparse. According to the diet’s official website, “The Whole30 is, at its heart, an elimination diet. Just a small amount of any of these inflammatory foods could break the healing cycle; promoting cravings, messing with blood sugar, disrupting the integrity of your digestive tract, and (most important) firing up the immune system.” In In fact, some of the foods followers of this diet are encouraged to eliminate are actually anti-inflammatory. For example, according to the diet rules, beans and whole grains must be avoided for 30 days. However, well-designed studies that have shown that these foods reduce systemic inflammation. At the same time, foods like red meat and whole eggs (which are encouraged) have been shown to be proinflammatory for many individuals.
We must also consider an individual’s health history. For those that follow a vegan or vegetarian eating pattern, the removal of beans and soy (another food that must be eliminated) could dramatically reduce their daily protein intake. Also, pregnant women and those who are planning to become pregnant would not be advised to follow the Whole30 diet.
The rules of the Whole30 diet also state that the meal pattern must be followed flawlessly for the entire month. Therefore, slip-ups (or lapses) are not allowed. If this does occur, the 30 days must begin all over again. However, with any behavior change, diet or otherwise, lapses are very common. Personally, I favor encouragement and forgiveness when guiding patients on their path to a healthier lifestyle.
Neal Malik, DrPH, MPH, RDN, CHES, EP-C
Chair, Department of Nutrition and Basic Sciences
Bastyr University California