Short answer:
I recommend having at least 3 servings of non-starchy vegetables each day, more is great too, but no need to overdo it. Like anything else, we can get too much of a good thing.
Long answer:
First, let's figure out what a serving is:
1 serving of non- starchy vegetables = 1 cup raw, 1/2 cup cooked, or 80 grams.
What are non-starchy vegetables?
How many should I eat each day?
The World Health Organization recommends 5 servings a day of both fruits and vegetables (1). I typically recommend at least 2 servings of fruit and 3 servings of vegetables. Fruit is very healthy, but it does have more natural sugar than vegetables do, and vegetables typically have higher vitamin and mineral profiles.
Why 5 servings a day?
Evidence shows that risk of chronic disease, such as heart disease, stroke, and some types of cancer, is lowered when at least 5 servings of fruits and vegetables are consumed each day.
Can I have more than 3 servings of vegetables?
Absolutely! There are a number reasons why consuming more than 3 servings per day is even better!
1. Nutrient density
Vegetables are extremely rich in vitamins and minerals, often providing well over our daily needs for specific nutrients in only 2 servings.
Take broccoli for example, according to Cronometer.com, 1 cup of cooked broccoli contains:
8% Vitamin B1
17% Vitamin B2
6% Vitamin B3
19% Vitamin B5
23% Vitamin B6
14% Choline
42% Folate
103% Vitamin A
134% Vitamin C
21% Vitamin E
244% Vitamin K
6% Calcium
10% Copper
5% Iron
10% Magnesium
16% Manganese
14% Phosphorus
17% Potassium
4% Selenium
8% Zinc
If you're curious why all of these vitamins and minerals are important, checkout Nutrition Basics & General Healthy Eating Guidelines, which provides an overview of what each nutrient does and where you can find it in foods.
In general, these nutrients keep our bodies functioning properly and prevent symptoms of deficiency and chronic disease.
In the words of Michael Pollan :
Every additional serving of vegetables and fruit reduces your risk of stroke by 5% and your risk of heart disease by 4%.
We only eat about 2 and 3 portions of vegetables and fruit in this country. If we up that by just one more, that would save 30,000 lives and $5 billion in healthcare costs (2).
2. Antioxidants
Vegetables are incredibly rich in these anti-inflammatory compounds, another big reason they help prevent and heal from chronic diseases. Chronic inflammation plays a large role in most ailments including heart disease, diabetes, cancer, and autoimmune diseases.
These compounds act against free radicals, decreasing inflammation. They also help boost our immune's defense system and help fight infection if pathogens do enter our bodies.
3. Digestion
Vegetables are also loaded with fiber, often provided 2-3 grams of mostly insoluble fiber per serving. Insoluble fiber is great at helping move things through the digestive system and feeding healthy gut bacteria.
Helping move things through is important as these "things" in the digestive system are waste matter, toxins, and excess hormones. We want these leaving our systems, not hanging around for a few days allowing them to re-enter our bodies. Nor, do we want constipation, which is uncomfortable and leads to feelings of bloat and fatigue.
The fiber helps feed our gut bacteria, which aids our overall health with everything from immune function, heart health, brain function, lung function, and hormone balance.
For this very reason, however, consuming too many vegetables can become problematic, causing digestive discomfort as the body tries to digest and breakdown all that roughage. So, enjoy until satisfied, but I don't recommend trying to win any contests for who can eat the most vegetables in one sitting, in one day, etc.
4. Weight loss
Vegetables help with weight loss due their nutrient density, antioxidants, and fiber because these things help our bodies stay healthy and function properly. When our bodies are healthy and functioning properly, they are more likely to relinquish excess body weight.
Additionally, vegetables are very low in calories, averaging about 50 calories per serving, which is a drop in the bucket compared to the 1800-2400 calories an average person needs per day.
When trying to achieve a calorie deficit, vegetables are great because despite being low in calories, they tend to help fill us up quickly and digest slowly due to their fiber and water content.
Conclusion:
Eating more vegetables is one of the best things you can do for your health. Enjoy at least 3 servings a day (1 cup raw or 1/2 cup cooked), but more is even better!
For more information, thepaleomom.com has some great articles on the importance of vegetables and how many to consume. I enjoy this resource because Dr. Sarah Ballantyne is a nutrition nerd (like me) very much for nutrient density and improving overall health. She always basis her recommendations and information on scientific evidence.
RECIPE
Simple Roasted Broccoli
Ingredients:
2 Heads of broccoli
1-2 Tbs olive oil
Few shakes each garlic powder, onion powder, salt and pepper OR your favorite seasoning blend (I love using Trader Joe's chili lime)
Instructions:
1. Preheat oven to 400°F.
2. Chop broccoli into florets (and stems if you like them).
3. Spread evenly on a baking sheet.
4. Pour 1-2 Tbs olive oil over broccoli.
5. Season broccoli with spices or seasoning blend of choice.
6. Shake baking sheet to help distribute oil and seasoning.
7. Roast for 15 minutes
8. Check and turn broccoli with a spatula.
9. Roast for another 15 minutes.
Sources
1. Why 5 A Day? NHS. https://www.nhs.uk/live-well/eat-well/why-5-a-day/.
2. In Defense of Food. Directed by Michael Schwartz. Produced by Michael Schwartz and Edward Gray, 2015.