The science behind the Original Whole30

Habit research says it can take anywhere from 18 to 254 (!) days to make a habit stick, depending largely on how emotionally tied you are to that habit. However, one study in 2021 found on average, a new habit takes 59 days to solidify. Creating new habits with food can be an emotional challenge, but asking someone to follow a strict elimination protocol for two months (or longer) isn’t reasonable or necessary for our purposes. In our decade-plus of clinical experience, we’ve found 30 days is the sweet spot. It’s long enough for you to see dramatic, life-changing results, but short enough to make the program feel attainable. (And when you factor in 10-14 days of reintroduction, you’re already three-quarters of the way to that 59-day benchmark!) *Source: The British Psychological Society

In order to accurately determine how certain foods are impacting your body, you need to completely eliminate them for the prescribed period of time. Eating even small amounts of foods to which you are sensitive can disrupt the process and interrupt your healing. Complete elimination, on the other hand, can bring about improvements in any number of symptoms or negative health effects, and makes it easier to identify potentially problematic food(s) during reintroduction.

Rushing through reintroduction can have the same negative consequences. Reintroducing food groups too quickly, or reintroducing too many at the same time, will make it hard (if not impossible) to accurately evaluate the impact of these foods. You won’t be able to identify which food flared your symptoms, tanked your energy, or disrupted your digestion.

To make the most of your Whole30 self-experiment, completely eliminate all of the recommended food groups for 30 straight days, then reintroduce carefully and systematically, one food group at a time, allowing 2-3 days between food groups. Read The Science Behind the Original Whole30 here, and The Science Behind the Plant-Based Whole30 articles.

Both programs offer a 30-day elimination and structured reintroduction period, with the goal of identifying food sensitivities, creating new habits, and restoring a healthy relationship with food. The Original and Plant-Based Whole30 programs differ only in their protein and fat sources, and in the length of time the programs have been available. The Original Whole30, founded in 2009, includes high-quality animal protein and encourages the use of some animal fats while eliminating legumes, including peanuts and soy. The Plant-Based Whole30 was launched in March 2022, after two years in development. The Plant-Based Whole30 does not include any animal protein and fats. It uses beans, lentils, peas, soy, compatible protein powders, nuts, and seeds to ensure adequate protein; and includes only plant-based fat sources.

Nope! Each program was carefully designed to function as a stand-alone, discrete elimination and reintroduction protocol, with carefully selected parameters that have proven incredibly effective for the vast majority of people who complete the program. Once you choose a program, please complete it exactly as written, unless your healthcare provider directs you otherwise. Read the Original Whole30 Program Rules, and the Plant-Based Whole30 Program Rules.

In 2018, Catherine Moring, PhD, RDN, BC-ADM, CDCES, who is Executive Director of the James C. Kennedy Wellness Center in Mississippi, conducted a pilot study with 45 Original Whole30 participants and shared her results with us. Dr. Moring and her team provided education about the side effects of chronic inflammation, the benefits of an elimination diet, and the Whole30 Rules and Recommendations. They also supported participants by teaching them how to prepare and enjoy minimally-processed, whole foods without focusing on calorie counting or food restriction. Dr. Moring’s team collected bloodwork and biometrics from the 45 study participants before and after completing the Original Whole30. Although the results of this cohort study have not yet been peer reviewed or published, Dr. Moring shared this overview of the outcomes with us.

• The average decrease in overall cholesterol was 13.37.
• The average reduction in triglycerides was 24.57.
• The average reduction in LDL (“bad”) cholesterol was 6.33.
• The majority of participants (70%) experienced lower blood sugar.
• Participants reduced their average blood-glucose level by 2.34 mg/dL, from slightly impaired to within normal limits.
• An estimated ⅔ of patients had lower blood pressure after Whole30.
• The average participant BMI decreased by 2.36 points, along with an average waist circumference reduction of 3.01 inches and an average weight loss of 12.11 pounds.
• Dr. Moring reported that several participants in the study were able to reverse pre-diabetes. Several others with diabetes were able to reach blood-glucose targets. One participant was able to stop taking insulin by the end of their Whole30.

Other non-scale victories reported by Whole30 participants in Dr. Moring’s cohort study included improved digestion, clear skin, better sleep, fewer medications needed, more energy, less anxiety and depression, reduced pain, improved focus, better moods, and increased self-confidence. Along that same line, our internal data (unpublished) also showed that in 2022, a small focus group of Whole30 participants experienced a 13.4% increase in positive body perception on the clinically validated Body Appreciation Scale.

A food intolerance means someone has difficulty digesting or processing components (often a protein or sugar) within the food. An example of a common food intolerance is lactose intolerance; difficulty digesting the carbohydrate component of milk products. A food intolerance is usually caused by the lack of an enzyme needed to digest the food, but can also be caused by digestive diseases (like Irritable Bowel Syndrome).

With food sensitivities, an individual experiences an immune reaction after consuming specific foods, which can generate a multitude of symptoms (like joint pain, stomach pain, fatigue, rashes, and brain fog). With food sensitivities, the body’s response can happen after eating, but could also be delayed. This means you may not notice symptoms for up to three days after consuming the food. Food sensitivities have no standard medical definition and are sometimes referred to as food intolerance, IgG, or IgA response. Harvard Medical School* says the gold standard for identifying food sensitivities is a structured elimination and reintroduction protocol.

With a food allergy, your body’s immune system reacts to a food or a substance in the food, identifying it as potentially harmful and creating antibodies to fight it off. This response is known as an IgE and/or histamine response. It’s often immediate (within two hours after eating the food) and can be life-threatening, like in the case of peanuts causing anaphylaxis. Individuals should work with their healthcare provider if they suspect or are currently navigating a food allergy.

*Source: Health Harvard Publishing – Harvard Medical School

You may have heard friends or family members talk about a “food sensitivity” test they did at home or with their provider. For some, this test can provide helpful direction towards customizing their elimination diet protocol. For others, it can do more harm than good. In fact, organizations including the American Academy of Allergy, Asthma and Immunology, and the Canadian Society of Allergy and Clinical Immunology have recommended against using IgG testing to diagnose food intolerances and sensitivities.

IgG-based food sensitivity tests have not been proven to identify food sensitivities, and often have false positives. Intestinal permeability or frequent exposures to a food can result in multiple foods being erroneously flagged as “culprits” (foods to which you’re sensitive). This can result in unnecessary and sometimes excessive restrictions. In addition, these tests can be expensive, and therefore aren’t accessible to all. By contrast, elimination protocols, like the Whole30, offer a free, clear, and effective way to assess which foods may be contributing to symptoms in your body. Read this article by Dr. Caroline Arreola for more.