The Lectin-Free Diet: What You Should Know

What is the Lectin-Free Diet?

The lectin-free diet eliminates foods containing lectins (a type of protein), such as wheat and other grains, dairy products from cows, beans, lentils, almost all fruits, and many vegetables. Many health professionals have expressed concern that eliminating such a large swath of foods could mean you’ll miss out on valuable nutrients, and the harmful effects of lectins have yet to be proven definitively.

The lectin-free diet was introduced by Steven Gundry, MD, a cardiologist and author of the 2017 book "The Plant Paradox." He and other proponents of the diet believe that eating lectins can lead to weight gain, brain fog, chronic inflammation, poor digestion from a disrupted microbiome, and other adverse symptoms.

The 7-Day Diet Plan

Unlike many diet plans, the lectin-free diet does not specify when you should eat or where to purchase ingredients. The diet also doesn’t restrict calories or portion sizes, so you’re free to eat to your level of fullness. Gundry claims in his book that “you can actually eat far more than you used to eat and still lose weight.”

Below is an example of what you might eat throughout 7 days on the lectin-free diet, beginning with phase one, which is the most restrictive and lasts three days. Note that this is an example of a diet that is not recommended. Consult your doctor before considering this diet.

What You Can Eat on the Lectin-Free Diet

You will cut back on—or eliminate—foods with lectins while on the lectin-free diet. Many common foods are approved on the plan, including those below.

Foods With Low or No Lectins

• Grass-fed meats
• Fish and seafood
• Pasture-raised poultry
• Plant-based meats without soy
• Buffalo, goat, or sheep dairy products
• Cruciferous vegetables
• Sweet potatoes
• Some nuts and seeds
• Olive, coconut, and avocado oil
• Coconut or almond flour
• Dark chocolate

What You Can't Eat on the Lectin-Free Diet

Foods not allowed on the lectin-free diet are those with a large amount of lectins, including those listed below.

Foods Containing Lectins

• Grain-fed meats, poultry, or seafood
• Most starchy foods, such as potatoes, rice, and grains
• Beans and lentils
• Nightshade vegetables, including tomatoes, eggplant, and peppers
• Fruits except for in-season berries
• Cow's milk dairy products
• Sugar and sugar-sweetened products
• Soy foods
  

Tips for the Lectin-Free Diet

This program comes down to eliminating foods that contain lectins. While some people may choose to dive cold turkey into the lectin-free diet, if you follow the plan you will progress through three phases.

• Phase One: A three-day “cleanse” eliminates almost everything but a handful of vegetables.
• Phase Two: Add in all remaining approved lectin-free foods.
• Phase Three (optional): Reduce your intake of all animal protein to 4 ounces or less per day and incorporate intermittent fasting.

Pros of the Lectin-Free Diet

It’s unclear whether eliminating lectins from your diet will lead to dramatic health outcomes like weight loss, reduced symptoms of chronic inflammation, or better digestion but a diet low in processed foods is shown to be beneficial.

• May reduce inflammatory response: Some research has indicated that lectins may activate an inflammatory response. A 2017 study in the Journal of Immunology identified a molecular pathway by which this can happen, theorizing that lectins might act as a "danger signal" that promotes autoimmune diseases. Therefore, reducing or eliminating lectins could potentially quell inflammation.
• May promote better nutrient absorption: Ever heard of "anti-nutrients"? Lectins are sometimes given this label because as they accumulate in the gut they can interfere with nutrient digestion and absorption. Elimination might allow your gut to better absorb important nutrients.
• May benefit people with irritable bowel syndrome (IBS): Many people with irritable bowel syndrome find that certain foods are triggers for symptoms—so it’s possible that foods with lectins could aggravate constipation, diarrhea, bloating, or other IBS woes. Some researchers have speculated that there may be an interplay between foods that contain lectins and those that contain FODMAPs (carbohydrates known to cause digestive problems in IBS sufferers). More research is needed to determine how removing lectins could benefit people with IBS.
• Emphasizes whole foods: There's one guarantee on a lectin-free diet: You won't be consuming many processed foods. Because of the diet's restrictions, you'll likely do most cooking at home with whole foods like vegetables, grass-fed meats, and plant-based fats. This could certainly be a benefit, as our society gets many calories from processed foods,
• May lower disease risk: Research shows that more processed foods in the diet are correlated with a greater risk of cardiovascular disease, hypertension, metabolic syndrome, cancer, obesity, and even depression. It's always a good idea to include whole, unprocessed foods wherever possible, and a lectin-free diet may help you do so.

Cons of the Lectin-Free Diet

The lectin-free diet is extremely restrictive and could result in some detrimental health effects.

• Limited evidence of effectiveness: Although some evidence exists to show that lectins might have harmful effects, there’s no consensus among nutrition experts that a lectin-free diet is a worthwhile means of treating or preventing any health condition.
• Available research does not apply to humans: Research on lectins’ effects on health is extremely limited, and much of it has been conducted on animals. Plus, even though some foods (such as raw kidney beans) contain high amounts of lectins that can cause food poisoning, cooking reduces those levels. (And when’s the last time you ate an uncooked kidney bean?)
• May be hard to consume enough key nutrients: Going without lectins might mean going without certain key nutrients, too. Curating a well-rounded diet with plenty of fiber is especially tough when you can’t eat grains or legumes, as is getting plenty of antioxidants when fruits are off the menu. And in the long term, not getting enough vitamins, minerals, and antioxidants from produce could result in nutrient deficiencies.
• Difficult to follow: There’s no denying that the lectin-free diet’s list of unapproved foods is quite long. Adhering to its strict guidelines will likely be challenging, and you may miss favorite foods that don’t make the cut. 
• May interfere with social eating: Any diet that eliminates large categories of foods has the potential to disrupt eating in a social context, meaning it may be challenging for you to find foods to eat while dining out, or at parties or gatherings. This can lead to feelings of anxiety, frustration, or isolation.
• Many approved foods are expensive: Although a lectin-free diet encourages consuming plenty of inexpensive vegetables like broccoli, carrots, and onions, other recommended foods could get pricey. Grass-fed meats; dairy products from goats, sheep, or buffalo; and high-dollar cooking oils like avocado and walnut aren’t exactly budget-friendly. Before starting the lectin-free diet, you may want to consider whether it’s financially feasible.
• May cause unwanted side effects: A diet excessively low in carbohydrates is often a formula for fatigue, headaches, mood swings, and other unpleasant side effects.
• May cause constipation: Without enough fiber from grains, legumes, fruits, and certain vegetables, you may become constipated.

Is the Lectin-Free Diet a Healthy Choice for You?

It is possible to consume all the nutrients you need for good health on a lectin-free diet. With the variety of foods on the diet’s “yes” list, you don’t necessarily have to miss out on the macro and micronutrients you need each day.

However, a lectin-free diet can have significant nutritional drawbacks. Carbs, which we need for energy, are hard to come by here, so getting the recommended 45% of 65% of your daily calories from them will be a stretch.

And since the diet does not include any grains, you won’t come close to reaching the 3 ounces per day of whole grains recommended by the 2020 Dietary Guidelines for Americans. Because of this lack of grains (as well as beans, lentils, and numerous vegetables), it may also be tough to reach your daily fiber target of at least 25 grams for women and 38 grams for men.

Additionally, because fruits are all but eliminated on a lectin-free diet, you might also struggle to consume enough of the nutrients they contain, such as vitamin C, potassium, and folate.

A Word From Verywell

For weight loss, more energy, and better digestion, some people have found success with a lectin-free diet—but the jury is still out on whether the evidence supports its use for any health condition. And since it cuts out so many foods known to be nutritious (like beans, grains, and fruits), this diet probably isn't worth following for most people.

If you're considering a lectin-free diet, take stock of how much you're willing to give up, and for what potential benefits. And, as with any diet, be sure to consult your physician or a registered dietitian before switching to a lectin-free lifestyle.

Remember, following a long- or short-term diet may not be necessary for you, and many diets don’t work long-term. While we do not endorse fad diet trends or unsustainable weight loss methods, we present the facts so you can make an informed decision that works best for your nutritional needs, genetic blueprint, budget, and goals.

If your goal is weight loss, remember that losing weight isn’t necessarily the same as being your healthiest self, and there are many other ways to pursue health. Exercise, sleep, and other lifestyle factors also play a major role in your overall health. The best diet is always the one that is balanced and fits your lifestyle.