First published 17 Nov 2017. Last updated 2 August 2021.
The Whole30 diet is a version of an elimination diet that is 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 begin to feel better and have a new relationship with food.
But do these claims hold water?
I recently wrote a piece titled Whole30 Diet – Short Term Reset or Long Term Lifestyle Change? and received a response from a reader that had tried the Whole30 diet.
She wasn’t too thrilled with my take on it and wrote:
“I do agree the Whole30 diet is a type of elimination diet, which is great for those of us trying to figure out our food allergies. Most people who go on the Whole30 are not trying to lose weight, but rather reduce inflammation, bloating, etc. The point of the 30 days is to merely see how our bodies react to certain foods, then after the 30 days we know what NOT to eat. I find the most helpful part of the program is cutting out sugar, which is usually the source of weight gain for our country.”
As you can imagine, I had some issues with her response.
First, much of what she described is anecdotal evidence. This basically means that the argument presented was based on experience, not research. The problem with basing conclusions on experience alone is that our memories–our interpretation of events–has to pass through a very biased filter: our brain! Humans are notoriously bad at both finding patterns and assuming cause-and-effect, even when they don’t exist in reality.
Here’s my take…
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 (overall score of 2 out of 5). 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 this diet is to follow the published guidelines for 30 days; however, they claim that followers will have a new relationship with food after this time period. But does following the Whole30 diet actually lead to lifestyle change?
There simply are not any 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 actually occur because individuals are following this diet, or due to other factors entirely. For example, when we are 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. Thus, we really need to ask whether weight loss is the reason individuals feel better when following the Whole30 diet, or whether it’s the diet itself. We will only know through well-designed research studies.
The evidence regarding the diet’s ability to heal is also sparse. According to the Whole30 diet 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.”
But the fact is that 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, there are a number of well-designed studies that have shown that these foods actually reduce systemic inflammation. At the same time, foods like red meat and whole eggs (which are encouraged) have shown to be pro-inflammatory in 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 that are planning to become pregnant would not be advised to follow the Whole30 diet.
The rules 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 Whole30 must be started from the beginning. However, with any change, lapses are very common.
Personally, I favor encouragement and forgiveness when guiding patients on their path to a healthier lifestyle.