The LEAP Diet - What is it - How does it work - Who is it for - Jenna Volpe RDN LD CLT

The LEAP Diet Protocol: What Is It, How Does It Work & Who Is It For?

In our modern-day chronic illness epidemic, millions of people each month are now scouring the internet for information on diets to help their inflammatory, autoimmune, and irritable bowel syndrome (IBS) conditions. Yet still, surprisingly very few of those people are aware of the LEAP diet protocol and its profound roles in reducing symptoms of inflammation among people with chronic conditions like IBS-D, fibromyalgia, unexplained rashes, migraines, immune imbalances, and more!

But since you’ve made it to my corner of the internet and landed on this post, perhaps you’ve at least heard of the LEAP diet. Or, maybe you’re just curious and eager to learn more about one of the inadvertently best-kept secrets in my industry of holistic health. Either way, you’re in the right place!

As a functional dietitian nutritionist and certified LEAP therapist (CLT), I’ve done my best to answer all your burning questions about LEAP and MRT in this article.

Disclaimer:  This isn’t medical advice. My goal is to educate you on the LEAP diet, so you can make more informed decisions about your health (with guidance and support from your healthcare team). 

  • I have no financial affiliations with Oxford in that I don’t receive any kind reimbursement from Oxford Biomedical Technologies for promoting or endorsing the MRT test, LEAP therapy, or CLT’s. I’m passionate about this branch of functional nutrition because of the wonderful life-changing impact it has had on many of my clients.

Now, let’s begin with the most obvious frequently asked question… 😀

What does LEAP stand for?

“LEAP” is an acronym which stands for “Lifestyle Eating and Performance.”  

The premise of LEAP is that when you employ certain lifestyle interventions, primarily via changing your eating habits to align with what you learn in this program, you can and will improve and enhance your performance and overall quality of life.

LEAP - Lifestyle Eating and Performance - logo

What is the LEAP diet?

The LEAP diet, aka the “Immunocalm diet” or “LEAP eating plan”, is an exceptionally customized oligoantigenic step-by-step elimination diet.  

  • “Oligoantigenic” in this context is referring to the strategic elimination of specific foods and/or chemicals which have been uncovered as sources of diet-induced inflammation in your body.

The ultimate goal and purpose of LEAP is to reduce inflammation in your body, relatively quickly, through identifying and addressing food sensitivities.

How and when did it start?

The framework of the LEAP diet program was originally developed by a team of registered dietitians, doctors, immunologists and other credentialed healthcare professionals back in the 1990s, based on over 100 collective years of clinical experience, research, and case-study observation in the field of food sensitivities.

What can you eat on this protocol?

The general backbone of the LEAP diet protocol is similar for everyone in that it includes a variety of foods from each food group, and remains in alignment with the MyPlate and Dietary Guidelines for Americans from a macro- and micronutrient standpoint.  However, your specific LEAP eating plan will be designed uniquely for you!

The list of foods you’ll be advised to eat, avoid, and limit on the LEAP diet will depend entirely on the results of your mediator release (MRT) food sensitivity test and a nutritional assessment which takes into account your food preferences, patterns of eating, medical history, weight history, digestive function, allergies, food intolerances, and more.

MRT - Mediator Release Testing for Food SensitivitesWhat is the MRT test?

The MRT test is a patented food sensitivity blood test designed and offered via Oxford Biochemical Technologies. This food sensitivity test is the standard diagnostic tool utilized in the LEAP program.  

MRT testing will show you a profile of your body’s inflammatory responses based on your degree of reactivity or “sensitivity” to 170 different tested foods and chemicals.

How does MRT work?

“Mediator release” is the end-point inflammatory response which gets measured indirectly by the MRT test. 

When your body is inflamed, it’s often a result of the release of mediators (inflammatory chemicals) such as histamine, cytokines, prostaglandins, or other chemicals, from your white blood cells into your bloodstream.  A variety of those chemical mediators are responsible for the cascade of unwanted inflammatory symptoms.

The level of mediator release going on in your blood is measured by the MRT test based on the degree of before-and-after change in density of your white blood cells after being exposed to each food and chemical extract.  

  • In a nutshell:  The greater the drop in white blood cell density after being exposed to a given food/chemical, the more mediators are getting released into your bloodstream (from inside the white blood cells), which translates to a higher inflammatory response to that food/chemical.

How does MRT compare to other food sensitivity tests?

MRT food sensitivity testing is more reliable, accurate, valid, and comprehensive compared to other food sensitivity tests.

This is because MRT measures the end-point inflammatory reaction (which could take place via multiple pathways and involve dozens of different mediators) following exposure to 170 different foods and chemicals individually.

Certain other food sensitivity tests may measure only specific types of mediator levels present in your blood (such as cytokines but not prostaglandins, for example).  

  • There are usually multiple types of mediators involved in inflammation, unique to each individual.  Measuring only one type of mediator out of dozens is very limiting and not always relevant.

Other types of food sensitivity tests may only measure one pathway.  For example, a commonly measured reaction pathway known as Immunoglobulin G or “IgG” is not always indicative of inflammation.  

  • Sometimes it’s considered normal and healthy to have an increased IgG response after eating certain foods.  This makes IgG food sensitivity testing less valid and reliable.

(You can learn more about MRT food sensitivity testing here.)

LEAP + MRT: a dynamic duo

The LEAP diet protocol can only be executed after you’ve completed an initial nutrition assessment with a certified LEAP therapist (CLT) and received your results from the MRT food sensitivity test.

On the LEAP eating plan, you’re essentially removing all possible dietary sources of inflammation quickly and without having to guess, because of the MRT results in combination with your clinical nutrition assessment. (“Test & assess, don’t guess!” is a saying you’ll hear often among many of my fellow functional medicine colleagues.)

MRT LEAP Program

What does the LEAP diet entail?

Step 1:  consulting your CLT

In the MRT + LEAP 1-1 Program, the first step is to meet with your CLT to review your MRT test results.

Step 2:  de-coding your MRT report + LEAP booklet

Your MRT report will include a panel of 170 different tested foods and chemicals, organized by category. 

You’ll also receive a 50+ page LEAP booklet summarizing your MRT test results and providing you with a bundle of meal planning resources, grocery shopping/restaurant dining tips, and simple recipes to help you get started.

  • Note: Along with the MRT test results, in the LEAP booklet you will also receive a computer-generated sample meal plan.  
    • The computer-generated meal plan is not customized to your individual needs and it’s not the same as the LEAP diet. It does not take into account your food preferences,  intolerances, food allergies, patterns of eating, medications, and your unique nutrient requirements. 
    • I advise my clients not to look at the computer-generated sample plan as it often creates unnecessary confusion.

Within each food group category, the foods/chemicals will be listed and color-coded in order of least reactive (green) to mild-moderately reactive (yellow), all the way down to highly reactive (red) if applicable.  

  • Green indicates those foods could be among your body’s best foods, while yellow and red indicate those foods could be inducing an inflammatory response in your body. 

Sample MRT test results


Non-reactive foods

When a food is showing up on the report in the green range, it means you likely aren’t having a significant inflammatory response in your immune system.  These foods are generally considered to be “non-reactive.”

  • Note:  This is not an allergy test or a food intolerance test, so if you’re still reacting negatively to a food that showed up on the MRT test as “non-reactive” or low-reactive, it’s likely another type of adverse food reaction. 
    • You can learn more about the key differences between food allergies, intolerances, and sensitivities here.

Mild to moderately reactive foods

The foods showing up in the yellow range on your MRT test report are found to be inducing a moderate level of mediator release (inflammatory response) in your body.

This “yellow” category of foods is usually the most difficult to identify through food logging, because the reactions are typically subtle, delayed (taking place up to 3 days after you ate the food), and/or dose-dependent (meaning you may tolerate a certain threshold of this food/chemical without any reaction.)

I find that most people typically have more moderate food sensitivities than severe ones.

Highly reactive foods

When a food is flagged as red (towards the very bottom section of each panel or category), it indicates that food is causing a clear inflammatory response in your body.  (This is a “highly reactive” food, or a “severe” food sensitivity.)

My clients are usually not too surprised when they see which foods end up getting flagged as red, with the exception of when it’s a food they don’t eat very often!

Typically, on the LEAP diet, the “gold standard” is to avoid the “red” highly reactive foods for at least 6 months before re-introducing gradually. (Ideally you want to be mostly symptom-free for a period of time 

Untested foods

Given there are *only* 170 foods and chemicals included in the MRT test panel, that means there are still hundreds of untested foods and chemicals remaining. This is where things get tricky, and this is where the full LEAP elimination and reintroduction protocol can be beneficial.

You won’t know for sure whether you react to these or not, unless you go through each phase of the LEAP diet, and make it all the way to phase 6.

Step 3: LEAP diet elimination and reintroduction phases

The details of each phase will be customized to you, and you actually get to participate in co-creating your LEAP eating plan alongside your LEAP therapist.  

You’ll also be advised on how to keep a food-symptom journal, so you and your CLT can track your progress and identify any potential hidden sources of reactive foods along the way.

Below is just a general overview of what you can expect in each phase of the full LEAP diet protocol.

Phase 1

You and your CLT will decide on a list of ~25 to 35 foods to begin with. These won’t just be a random list of foods; you’ll get to pick a handful of non-reactive foods from each category of your MRT test report (fruits, veggies, spices, fats, proteins, grains/starches, and miscellaneous) based on what you enjoy and what you know works well for your body.

Your LEAP therapist will support you by providing a compiled list of these foods as well as some sample meal ideas, food combinations, and recipes using only the “allowed” foods.

In this phase, since inflammation levels typically drop fast, people tend to lose a few pounds of water weight from dehydration, so your CLT will also talk to you about the best ways to stay hydrated and maintain proper nutrition in these early stages of healing. (When we’re inflamed, we tend to retain fluid!)

Phase 2

One your symptoms have been noticeably reduced, (usually within the first week), you get to move onto phase 2! In this phase, you and your CLT will co-select another set of non-reactive foods from each category. 

You’ll be able to start adding no more than one new food per day (or every few days) from the list of foods selected, since there’s a window of delayed reactivity.

Phases 3-5

In these phases, you continue what you started in Phase 2, adding up to one new food each day.  

In phases 3-5, you can also start exploring different types of fiber supplements (as needed) as well as dairy (if non-reactive, and as tolerated) which aren’t encouraged in the first few phases.

Phase 6

In phase 6, you get to start increasing variety by adding in untested foods (foods not included in the list of 170 foods and chemicals on the MRT test panel).

You’ll also begin learning more about rotational diets, which help to reduce the likelihood of developing new sensitivities to foods you’re eating too often (which often happens in cases of leaky gut syndrome). (1)

LEAP ImmunoCalm Diet Program - Sample Food Reintroduction Plan

How does LEAP compare to other anti-inflammatory nutrition protocols and IBS diets?

Elimination diets

Unlike most types of elimination diets out there, which tend to heavily emphasize what not to eat, LEAP serves to help you identify your body’s best foods while maintaining a nutritionally balanced diet and receiving clinical supervision from a registered dietitian the entire time.

Other elimination diets are also based primarily on guess-work, versus clinical blood work.  I see this as throwing things at the wall until something sticks.

  • While guess-work is sometimes necessary (in the case of food intolerances), when it comes to diet-induced inflammation (which is caused by food sensitivities), running the MRT test paired with the LEAP diet will save you years of unnecessary frustration!

Anti-inflammatory diets

I find the LEAP protocol to be superior to other anti-inflammatory diets out there which typically feature a list of “superfoods” or antioxidant-rich fruits, veggies, herbs, and spices.  

This is because when it comes to food sensitivities, your body doesn’t care how many micronutrients (vitamins, minerals, or antioxidants) are in a particular food or herb.   It’s possible to be “sensitive” or “reactive” to virtually any food, herb, spice, or chemical!  

  • In fact, I’ve seen people in my clinic have adverse reactions to commonly deemed “anti-inflammatory” or “healthy” foods more times than I can count.

LEAP is the only version of an anti-inflammatory diet that takes into account what’s going on in YOUR body!

IBS diets

The LEAP diet may or may not be the best IBS diet for you, depending on your symptoms, IBS subtype, and the underlying root causes of your IBS.

  • If you’re navigating IBS, make sure to read more on IBS diets before diving head-first into LEAP therapy!

Who can benefit from MRT testing and the LEAP diet?

While MRT and LEAP therapy can be super effective for those who meet clinical criteria and are motivated to implement what they learn, this stuff is still not for everyone!  

MRT testing is not cheap, and LEAP is pretty restrictive, especially in the beginning.  Going down this path requires quite a bit of commitment to say the least. I’d even go as far as calling this a lifestyle overhaul!

All of that said, LEAP therapists are trained to screen you before moving forward with recommending and performing MRT testing and the LEAP diet. 

  • We’ll provide a consultation to make sure you meet clinical criteria for MRT, and we’ll also ask a series of questions to make sure the LEAP diet is a good fit from a behavioral change standpoint.

Clinical criteria for MRT testing

MRT ain’t cheap, and LEAP is no picnic!  That said, it’s important to first make sure this path is clinically relevant and justified.

From a clinical and functional nutrition standpoint, you may be a good candidate for the MRT test and LEAP diet if you’ve been experiencing any of the following conditions, which tend to get triggered or exacerbated by underlying food sensitivities:

  • Diarrhea-predominant IBS
  • Functional diarrhea
  • Crohn’s disease
  • Ulcerative colitis
  • Unexplained gastritis
  • Chronic heartburn / gastroesophageal reflux disease (GERD)
  • Barrett’s esophagus
  • Eosinophilic esophagitis (EOE)
  • Fibromyalgia
  • Arthritis
  • Psoriasis
  • Migraines
  • Eczema
  • Various other types of autoimmune disorders
  • Hives
  • Mast cell activation syndrome (MCAS)
  • Hormonal imbalance
  • Acne
  • Chronic fatigue
  • Unexplained weight gain
  • Unexplained fluid retention
  • Lymphedema
  • ADHD

Behavioral criteria for the LEAP diet protocol

While the idea of this diet might sound great on paper (and in many ways it is!), as I mentioned earlier, it’s not for everyone. 

Embarking on dietary restrictions can be like playing with fire, even when you have the best of intentions. Dietary restrictions can quickly spiral into disordered eating, unintentional weight loss, and/or nutritional deficiencies.

There are certain qualities which can make-or–break your ability to execute this type of plan and remain consistent enough to get results. 

To meet behavioral criteria for the LEAP diet, I recommend having:

  • An open mind 
  • A growth mindset (versus a fixed mindset)
  • A strong conviction
  • Delayed gratification
  • The means and willingness to invest in yourself
  • Eagerness to put yourself first and commit to your health
  • A healthy relationship with food and self care
  • A decent foundation of meal planning and balanced eating
  • Sustainable access to food

Who is it NOT for?

Clinically speaking, not all conditions are caused or triggered by food sensitivities.

  • For example, constipation, gas, bloating, and/or small intestinal bacterial overgrowth (SIBO) as stand-alone symptoms don’t meet criteria for MRT testing unless any of the above clinical symptoms/conditions are present. 

I would also not enroll someone in this program who is underweight (with a body mass index or “BMI” below 19), malnourished, and/or who has a history of or tendency towards disordered eating.

MRT and LEAP are not a good fit for you if:

  • You’re underweight or navigating multiple nutrition deficiencies
  • You have an eating disorder or a tendency towards disordered eating
  • You have a tendency towards yo-yo dieting
  • You just want a quick fix
  • You’re not ready to make diet and lifestyle changes
  • You don’t value your health as a top priority
  • You tend to just throw money at your problems hoping they will go away
  • You’re too busy to make time for this

You’ll also be required to submit a 5-day food log prior to beginning the LEAP program, so your CLT will have a more objective baseline to help you determine whether this is the right time or not.

Benefits, cons, and limitations 

Real results!

The whole purpose and primary benefit of the LEAP diet program is the amazing results waiting for you on the other side, for those who are in alignment and who stay the course!

Quality of life is different for everyone.  But if you find value in feeling amazing in your body, living pain-free, having more energy, and ultimately getting your life back… your mind and body will thank you for those few months you spent living in a “bubble” while moving your way through the LEAP eating plan.

Personal empowerment

There’s nothing more empowering (in my opinion) than healing yourself through lifestyle change!  

We can’t really heal on the physical level without also undergoing transformation on the mental, emotional and spiritual levels. On this path, you must transform and change on all levels in order to move forward.  

Very restrictive

As I’ve mentioned many times in multiple articles, dietary restriction isn’t always safe or recommended.  The LEAP diet is definitely restrictive and it’s got the potential to trigger people with disordered eating or an unhealthy relationship with food.  

This diet may also be too restrictive for those who are underweight or navigating unintentional weight loss or multiple nutritional deficiencies. 


MRT isn’t cheap, and neither is working 1:1 with a LEAP therapist in many cases.  (In all fairness, we often get what we pay for!) But if you aren’t serious about this journey or if you have a tendency to just throw money at your problems to make them go away without doing the work, this path probably isn’t for you.


Let’s be frank – there’s never a “right time” when it comes to making diet and lifestyle changes or dealing with inconveniences.

  • When it isn’t the holidays, it’s birthday celebrations, anniversaries, Valentine candy, spring break, or the summer season!  These are constants, not variables; every season has its own unique challenge to navigate, but trust me – it’s all figureoutable!

Choosing the LEAP path means not taking the path of least resistance, and that comes with a bit of temporary constraint and discomfort.  Only you get to decide if going down this path is worth the inconvenience!

Untested foods 

Untested foods/chemicals are a limitation of the LEAP protocol.

As I mentioned earlier, there are lots of untested foods and chemicals which are very difficult to avoid day-to-day, especially if you eat lots of processed foods which usually contain a laundry list of ingredients. 

Eating untested foods (intentionally or unintentionally), especially in the early phases of your healing journey can create confusion and frustration.

On the other hand, reintroducing and testing each untested ingredient one-by-one, one at a time, is extremely tedious and not always feasible. 

Additional frequently asked questions

“Can’t I just avoid the reds & yellows?”

This is a question that comes up a lot! There isn’t a right or wrong answer; it depends on where you’re at, what you want, and your level of readiness to change.  

Many people will just get the MRT test and opt to remove the red/yellow (moderately reactive to highly reactive) foods from their diet, since it’s less restrictive. 

  • Going that route is very hit-or-miss.  Sometimes people can get profound results (up to 50% relief within a few weeks, just from removing a few foods) and not feel the need to take things any further, but most will likely hit a glass ceiling with their healing.

Those who would like to make quantum leaps in their health (pun intended) will find relief faster by going through the 6 phases of the official LEAP Immunocalm diet.  While that route is more restrictive, it’s for a relatively short amount of time and may be worth the investment if you’ve been suffering for a long time and want relief sooner rather than later!

“How often should I avoid the reds and yellows?”

This is something you should discuss with your CLT, but it’s considered best practice to wait at least 3 months before re-introducing the “yellow” moderately-reactive foods, and to wait at least 6 months before reintroducing the “red” highly reactive foods.  

Generally you’ll also want to wait until you’ve been symptom-free for a period of time before reintroducing these types of foods into your lifestyle.

“What if it doesn’t work?”

The #1 reason LEAP doesn’t work (assuming you meet all the clinical and behavioral criteria to go down this path) is when you’re not sticking to the plan – whether intentionally or not.

There are certain ingredients which are very difficult to avoid; for example, citric acid comes from corn, and it’s in almost everything! Or salicylic acid is a chemical which is present in virtually all fruits, veggies, spices and some other foods in varying quantities. 

This is where food logging comes into play.  Your CLT will advise you to keep a detailed food-symptom journal, so if things don’t go well, you can retrace your steps and identify any potential hidden blind spots.

LEAP will also “not work” if there are other underlying functional medical conditions (such as mycotoxins, histamine intolerance, or candida to name a few examples) which you’d need address in addition to the LEAP protocol.

Recap and next steps

The MRT test paired with the 6-part LEAP diet protocol as a “dynamic duo” are a highly effective, little-known way to combat chronic inflammation naturally, without the guesswork.  (Test and assess, don’t guess!)

The “secret sauce” of MRT + LEAP is to identify, remove, and replace all known sources of diet-induced inflammation while properly nourishing and supporting the body in ways that promote healing.

While the LEAP Immunocalm diet isn’t for everyone, and it’s certainly no cake-walk, in a few months’ time (for those who meet clinical and behavioral criteria), LEAP is a complete game-changer which can alter the entire trajectory of your life for the better.

If you live in the United States, and you’d like to consider taking the next step (or “leap”) on your journey together, let’s chat! Feel free to apply for a Complimentary Connect Call with me so we can see if we’d be a great fit working together.

Click here to book a free call with Jenna Volpe

Or if you know someone else who may benefit from learning more about the LEAP diet / MRT LEAP Program, please share this article with them!

2 thoughts on “The LEAP Diet Protocol: What Is It, How Does It Work & Who Is It For?”

    1. Hello! Unfortunately I don’t know of any customized home service plans for the MRT test results. However, my team and I are in the process of creating a self-study course to help people better understand and navigate their MRT test results since it can get confusing in many cases. Let me know if that is something you might be interested in, and we’ll keep you posted! -Jenna

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