What Is the Lectin-Free Diet?

Beans and grains

At Verywell, we believe there is no one-size-fits-all approach to a healthy lifestyle. Successful eating plans need to be individualized and take the whole person into consideration. Prior to starting a new diet plan, consult with your healthcare provider or a registered dietitian, especially if you have an underlying health condition.

You’ve heard of gluten as an ingredient many people try to avoid in their foods—but have you heard of lectins? Lectins are a protein in numerous foods that binds to carbohydrates and can accumulate in the gut, which may cause health problems in some people. Although scientists have been aware of lectins for quite some time, a diet that eliminates them is relatively new, introduced by cardiologist Dr. Steven Gundry in his popular 2017 book "The Plant Paradox."

According to Gundry, lectins in foods can cause harm to health in several ways. He and other proponents of a lectin-free diet believe that eating these proteins can lead to weight gain, brain fog, chronic inflammation, poor digestion from a disrupted microbiome, and other adverse symptoms. On a lectin-free diet, you’ll eliminate foods that contain lectins, such as wheat and other grains, dairy products from cows, beans and lentils, almost all fruits, and many vegetables.

A lectin-free diet may be helpful for people with certain health issues, but it hasn’t been embraced by nutrition experts as a healthful way to eat or as a means of treating specific health conditions. Many health professionals have expressed concern that eliminating such a large swath of foods could mean you’ll miss out on valuable nutrients. Plus, the harmful effects of lectins have yet to be proven definitively.

What Experts Say

"Advocates of a lectin-free diet believe that you should avoid foods that contain lectins, such as, legumes and whole grains. But, these plant-based foods contain important nutrients, including fiber and a variety of micronutrients. Studies have found that those people who consume more plants have many health benefits, including a reduced risk for heart disease. Soaking, cooking, sprouting, and fermenting these foods destroys most lectins. If you are trying a lectin-free diet for medical purposes, consult with a registered dietitian to ensure your eating plan meets your nutrient needs and goals."

Barbie Cervoni, MS, RD, CDCES, CDN

What Can You Eat?

On a lectin-free diet you will, of course, cut back on (or completely eliminate) foods with lectins. But many common foods are approved on the diet. Foods that contain low amounts of lectins include pasture-raised meats, fish, cheeses made with goat, sheep, or buffalo milk, certain vegetables, berries, most nuts, oils like avocado and olive oil, and dark chocolate. Dr. Gundry’s website provides a comprehensive list of “yes” and “no” foods for reference.

What You Need to Know

While a lectin-free diet does outline approved and unapproved foods, unlike many diet plans, it doesn’t specify details like when you must eat your meals or where you need to purchase ingredients. It also doesn’t restrict calories or portion sizes, so you’re free to eat to your level of fulness. In fact, Gundry claims in "The Plant Paradox" that “you can actually eat far more than you used to eat and still lose weight.” On this diet, it really all comes down to eliminating foods that contain lectins.

Some people may dive right into a lectin-free diet cold turkey, but to follow Gundry’s official plan, you’ll progress through three phases.

  • Phase One: A three-day “cleanse” that 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.
What to Eat
  • 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

What Not to Eat
  • 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

Pros and Cons

Pros
  • May reduce inflammatory response

  • May promote better nutrient absorption

  • May benefit people with irritable bowel syndrome (IBS)

  • Focuses on whole foods

Cons
  • Limited evidence of effectiveness

  • May be hard to consume enough key nutrients

  • Difficult to follow

  • May interfere with social eating

  • Many approved foods are expensive

Pros

May Reduce Inflammatory Response

Some research has indicated that eating lectins could 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"? It sounds like a contradiction in terms, but lectins are sometimes given this label because, as they accumulate in the gut, they can interfere with nutrient digestion and absorption. Getting them out of your diet 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). Still, more research is needed to determine exactly how removing lectins could benefit people with IBS.

Focuses on Whole Foods

There's one guarantee on a lectin-free diet: you won't be consuming many processed foods. Because of the restrictions of the diet, you'll likely do most of your cooking at home with whole foods like vegetables, grass-fed meats, and plant-based fats.

In a society that gets far too many calories from processed and "junk" foods, this could certainly be a benefit. You might also learn some valuable kitchen skills by having to cook at home!

Cons

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 any health condition.

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) definitely contain high enough amounts of lectins to cause food poisoning, cooking reduces them down to a safe level. (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.

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 a challenge, 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. When dining out or at parties or gatherings, you may not be able to take part in the food offered. This can lead to feelings of anxiety or frustration.

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 getting started with this diet, you may want to consider whether it’s financially feasible.

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 are definitely hard to come by here, so getting the recommended 45-65% 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 25 grams for women and 38 grams for men.

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

It’s possible to get all your necessary nutrients on a lectin-free diet, but doing so may require some careful planning. Fiber and micronutrients like vitamin C, potassium, and folate are particularly at risk of going missing on this eating plan.

Health Benefits

It’s not clear whether taking lectins out of your diet will lead to dramatic health outcomes like weight loss, reduced symptoms of chronic inflammation, or better digestion—but crafting a diet low in processed foods might have major benefits. 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.

Health Risks

The biggest disadvantage of a lectin-free diet is arguably its restrictive nature, which could trickle down to some detrimental health effects. A diet excessively low in carbohydrates is often a formula for fatigue, headaches, mood swings, and other unpleasant side effects.

Without enough fiber from grains, legumes, fruits, and certain vegetables, you may end up constipated. And in the long-term, not getting enough vitamins, minerals, and antioxidants from produce could result in nutrient deficiencies.

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-term or short-term diet may not be necessary for you and many diets out there simply don’t work, especially 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.

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Article Sources
Verywell Fit uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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