Can Eating Too Many Vegetables Be Unhealthy?

basket containing wide variety of vegetables

Conventional wisdom suggests that we need to eat more, not less vegetables. And while no one can deny the importance of vegetables in a diet, there may be such a thing as having too much of a good thing.


With the growing popularity of green smoothies, it’s now easier for many people to go above and beyond their daily requirement for greens. Take into account that more and more people are choosing a vegetarian or vegan diet, and there is even more potential to over-consume or consistently consume the wrong types of vegetables.


Too much of a good thing?

To see how too much of a good thing can be bad for you, we can look to the recent study on kale. Kale is high in a number of vitamins, fiber, iron, calcium, and is a powerful anti-oxidant and anti-inflammatory. However, a study conducted by biologist Ernie Hubbard revealed that kale contains a number of heavy metals that can be toxic to the body in large doses.


Studying urine samples from patients complaining of fatigue, digestive problems, and skin issues, Hubbard found high amounts of thallium, which is a common ingredient in rat poison. Afterwards, he discovered that kale and other cruciferous vegetables such as broccoli and cauliflower, absorb thallium from soil. Although this and other heavy metals in kale exist in very small amounts, consuming large amounts of kale each day can raise those levels and lead to the health issues the patients were complaining about.1


Another potential issue with raw cruciferous vegetables, as Dr. Michael Greger points out, is that the compounds in them can block iodine uptake in the thyroid. Some vegetables have more of this compound than others. Dr. Greger also states that that just 3 cups of raw mustard greens, for example, is too much.2


Vegetable fibers and digestion

young woman drinking green vegetable smoothie

Yet another factor to consider with vegetables is that many of them, such as greens, peas, and cauliflower, are high in insoluble fiber. Although the right amount of this type of fiber helps keep you regular, too much of it can actually irritate the stomach. This is especially the case if you have an existing gut issue such as IBS.3 4


Because it can inflame the gut, some experts advise consuming less insoluble fiber and adding more soluble fiber. In addition to this recommendation, licensed acupuncturist Chris Kresser advises reducing the variety of vegetables you eat if you are experiencing digestive issues.5


If you still want to enjoy vegetables that are high in fiber, cooking them may be an effective solution for you. Cooking vegetables, especially cruciferous ones like broccoli, cabbage, and cauliflower, reduces their fiber content (as well as their compounds that block iodine uptake), making them easier on your stomach.


Of course, along with potentially limiting your fiber intake from vegetables, you should also consider the source of your vegetables. You may want to choose only organic vegetables from trusted sources to avoid potential issues caused by pesticides and herbicides.


Finding the sweet spot

The American Heart Association recommends getting 25 to 30 grams of fiber from food sources per day.6 While most people don’t consume enough fiber, those who get too much of it may experience health problems such as bloating, abdominal pain, constipation, and fatigue.


If eating too many vegetables is putting you well over the recommended amount, you should consider reducing the amount of veggies you eat, cooking them, replacing high-fiber veggies with low-fiber ones, or perhaps doing a combination of all of the above.


In addition to potentially overloading your body with fiber, certain vegetables can be toxic to the body for other reasons—particularly when they’re consumed in high amounts. As such, it is generally recommended to consume no more than 5 servings of vegetables per day.


To sum it up, vegetables should be a key part of any diet—but you don’t want to overdo it. If you want to know more about how to get the right types of vegetables in the right amounts for your specific situation, make sure to talk with a qualified dietitian or nutritionist.




seth photoAbout Seth Morris
Seth Morris is an experienced article writer with a background in marketing, Web content creation, and health research. In addition to writing and editing content for the ZYTO website and blog, he has written hundreds of articles for various websites on topics such as holistic wellness, health technology, and Internet marketing. Seth has earned Bachelor’s Degrees in Business Management as well as Literary Studies.





1. Hinde, Natasha. “Hidden Health Dangers of Kale: Traces of Rat Poison Found in Popular Superfood.” HuffPost.

2. Gregor, Michael. “Overdosing on Greens.”

3. Nagarajan, N., A. Morden, et al. “The role of fiber supplementation in the treatment of irritable bowel syndrome: a systematic review and meta-analysis.” European Journal of Gastroenterology & Hepatology 27, no. 9 (2015): 1002-1010.

4. McRorie Jr., J.W. “Evidence-Based Approach to Fiber Supplements and Clinically Meaningful Health Benefits, Part 2” Nutrition Today 50, no. 2 (2015) 90-97.

5. Kresser, Chris. “Got digestive problems? Take it easy on the veggies.” Chris Kresser.

6. “Increasing Fiber Intake” The Regents of the University of California.


The information provided in this article is intended to improve, not replace, the direct relationship between the client (or site visitor) and healthcare professionals.

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