In nutritional circles there has been some worrying evidence about the way fructose is metabolised in the liver, causing weight gain, but this evidence results from animals being fed large amounts of pure, isolated fructose. In this form, fructose does act much like a toxin in the body, and it would be a terrible idea to start sweetening your food with pure fructose. But because fructose isn’t found in isolation in nature or even in our food supply, these studies are largely irrelevant to practical nutrition.
Fruit: an unhealthy sugar?
Although conventional wisdom holds that fruit is unquestionably a health food, the push to avoid sugar and excess carbohydrates has in many cases left people hesitant, even afraid to eat fruit. While it’s typically acknowledged that eating an apple is better than eating a bag of candy, fruit is still often seen as a source of sugar that should be consumed in strict moderation.
However the fiber and water found in whole fruit increase satiety, which makes it less likely that you’ll go into caloric excess. Studies going back more than forty years have shown that naturally occurring sugars in fruits are beneficial to health and do not promote weight gain. The danger comes from over-juicing and too many smoothies.