Fruit is one of the healthiest foods on the planet, but it’s also a natural source of sugar. Does that mean the sugar in fruit is bad for you? And will fruit cause you to gain weight?

One of the biggest complaints I see from people who are new to making smoothies or even eating a more plant-based diet is how much fruit they’re eating — and not in a good way.

Fruits are a natural source of sugar, but does that mean the sugar in fruit is bad for you?

Here’s the sweet truth about fruit...

Fructose is a type of monosaccharide — the building block of carbohydrates.

Fructose occurs naturally in fruit, root vegetables, honey and agave — it’s what makes fruit tastes sweet.

Most people are more familiar with fructose in its other form: table sugar or sucrose. Fructose makes up 50% of table sugar, the other 50% is glucose.

The body metabolizes glucose and fructose differently. While pretty much every cell in your body can use glucose for energy, only the liver can convert fructose into glucose.

Today the average American consumes 55 grams of fructose PER DAY! And most of it comes from the refined sugars found in soda and processed foods. That’s nearly three times as much fructose than Americans who lived during the early 1900s. They averaged around 15 grams (or half an ounce). However, their fructose mostly came from fruits and vegetables.

Consuming excessive amounts of fructose can be harmful to your health. It can lead to weight gain, heart disease, type 2 diabetes and other chronic diseases that plague those who consume the western diet.

There’s a very important difference between sugar in its natural form (i.e. the sugar in fruit, the way nature intended) and industrial sugars, such as table sugar, sucrose and high-fructose corn syrup. They all have very different effects on the body.

In other words, the sugar in fruit is not the same as added sugars.

Compared to added sugars, the amount of sugar in fruit is relatively low.

Fruit also contains soluble and insoluble fiber. Together, these two types of fiber form a gel-like substance in the small intestine, which prevents a significant portion of the fruit’s sugar from being absorbed early on during the digestive process.

According to Dr. David Lustig, “Like stopping a tsunami wave by building an underwater wall, this gel barrier limits the rate of sugar absorption so that the liver is not overwhelmed.”

What about blood sugar spikes? Fruit can actually help.

Take berries, for example. One study showed that berries not only help control blood sugar, but also improves control. Why? Researchers believe special phytonutrients may be responsible for slowing sugar uptake into the bloodstream.

Berries can also blunt the insulin spike from other high glycemic foods, such as bread.

Bananas (a popular smoothie ingredient) have also been shown to improve blood sugars over time. And mangoes have a similar effect.

One of the biggest misconceptions is that the sugar in fruit will make you gain weight.

Fruit has a lot of additional nutrients that you can’t find in added sugars, such as vitamins, minerals and antioxidants.

Compared to other foods that lack fiber, the fiber in fruit also helps you feel more full.

There are also multiple studies that show fruit can actually reduce your risk of obesity.

Consider this 2011 study published in “Metabolism” that compared two diets: one that restricted fructose from both added sugars and fruit and one that only restricted fructose from added sugars.

The diet that kept the fruit did better. In fact, people lost MORE weight with the extra fruit present than if all fructose was restricted.

I’m glad you asked because it’s actually been put to the test!

Researchers gave 17 people 20 servings of fruit a day, which is the equivalent of 8 cans of soda. After 3 to 6 months, there were no reports of adverse effects for body weight, blood pressure, and insulin and lipid levels.

Another study reported similar results. They also recorded a 38 point drop in LDL or “bad” cholesterol.

Some diabetics may restrict their fruit intake because of the sugar in fruit. However, fresh fruit can be part of a healthy diet for those with diabetes. In fact, fruit has actually been shown to be beneficial.

In one Danish study, type 2 diabetics were randomized into two groups: one group was told to eat at least two pieces of fruit a day, and the other group was told to eat now more than two fruits a day.

The group who reduced their fruit consumption didn’t see any effect on the control of their diabetes or weight. The researchers concluded that patients with type 2 diabetes should not reduce their fruit intake.

Other studies have shown that low-dose fructose may actually benefit blood sugar control.

Fruit can also help prevent type 2 diabetes. According to Dr. Joel Fuhrman, eating three servings of fresh fruit (in its whole form, not fruit juice) each day is associated with an 18% decrease in risk of diabetes.

However, he does recommend that those who are diabetic stick to low sugar fruits like berries, kiwi, oranges, and melon to minimize glycemic effects.

Fewer than 1 in 10 Americans meet the minimum daily fruit recommendation, which is 1½-2 cups per day.

As Dr. Michael Greger says: “We should stuff our face with as many fruits and vegetables as possible.” But when it comes to fructose in the form of added sugars (table sugar, high-fructose corn syrup) you should definitely limit your consumption.

If you’re worried about too much fruit in your smoothies, add some greens or vegetables.

Need some smoothie inspiration? Click here for some of our favorite smoothie recipes.