“Eat your fruits and vegetables!” You’ve probably heard that nagging scold more often than any other nutritional advice — not only from your mother but from doctors, health organizations, and governments — over the last four decades.
Eating fruits and veggies is so often recommended as the best way to live longer, healthier lives, that questioning it seems unbelievably controversial. After all, observations show that healthy people who eat fruits and vegetables can consistently live into their 90’s and 100’s.1 While this may show that fruits and veggies can be part of a healthy lifestyle for some, it does not prove that they are required for a healthy lifestyle for everyone.
How many fruits and vegetables do we need to eat? Might some people be better off eating fewer than recommended? More provocatively, do we need any at all? In a world where fruit bowls and green smoothies are seen as virtuous and bacon is viewed as sinful, it may seem difficult to even consider these possibilities.
Yes, there’s been a lot of research on the health benefits of fruits and vegetables, but is it rigorous enough to recommend a standard minimum daily intake? And does the quality of the rest of your diet make a difference in that recommendation? Read on to learn where the scientific evidence currently stands on fruits and vegetables.
1. What are fruits?
Fruits are the seed-containing portion of various flowering plants. They grow exclusively above ground.
Different types of fruit
The broad categories of fruit include pome, citrus, tropical, melons, stone fruits and berries. Most fruits taste sweet, although citrus varieties are often sour or bitter. With the exception of bananas, most domesticated fruits are juicy due to their high water content.
Nutritional composition of fruits
Nearly all of the calories in fruit come from sugar — not surprising, given their sweet taste. Their net carb counts span a large range: 5 grams to 20 grams of carbs per 100 grams (3.5 ounces) of fruit, depending on the type. A single mid-sized orange would have about 12 grams of carbs and a banana at least 23 grams.
2. What are vegetables?
Speaking from a botanical or gardening point of view, vegetables are the leaves, stems or roots of plants. However, many non-sweet fruits are commonly considered vegetables for eating or cooking purposes.
Different types of vegetables
Vegetables can be broadly classified into four categories:
- Above-ground vegetables: greens (spinach, lettuce, chard, et cetera), cruciferous vegetables (broccoli, Brussels sprouts, cabbage, cauliflower, kale, et cetera), bulbs (onions, garlic) and fungi (mushrooms).
- Below-ground/root/starchy vegetables: beets, carrots, parsnips, rutabagas, turnips, yams, potatoes, sweet potatoes, etc.
- Gourds: pumpkins, hard-shelled squashes, and other winter squashes.
- Technically fruits but treated like vegetables: avocados, olives, bell peppers, eggplant, tomatoes, and zucchini. Unlike other fruits, these aren’t sweet and are often prepared and consumed with other vegetables. Avocados and olives are unique among fruits and vegetables because most of their calories come from fat rather than sugar or starch.
Nutritional composition of vegetables
Non-starchy vegetables are keto-friendly foods that provide 5 or fewer grams of net carbs per 100-gram (3.5-ounce) serving. Not so for the root and starchy vegetables, though, which range from 6 to 17 grams of net carbs per serving. Vegetables usually contain moderate to high amounts of fiber, especially avocado — which also happens to be among the lowest in net carbs.