Getting enough fiber is one of the healthiest adjustments you can make to your diet.
But despite decades of nutritional advice, research shows that the vast majority of Americans don’t consume enough fiber, with only 4 percent of men and 11 percent of women meeting recommended levels.
It turns out that a way to bridge this enormous gap is hiding right in front of us.
In a new study in the International Journal of Food and Nutrition SciencesResearchers have found that the parts of fruits and vegetables that people regularly throw away as food scraps often contain more fiber than the parts they actually eat.
If we could change this behavior and stop throwing these precious parts of fiber-rich fruits and vegetables in the trash, we could improve our health, reduce food waste and also save money.
“This isn’t about perfection or forcing people to eat unpalatable foods,” says Rachel Gibson, a nutrition scientist at King’s College London.
“It’s about recognizing the nutritional value of components that we have been conditioned to reject.”
In the study, Gibson and his fellow researchers analyzed the components of 12 common fruits and vegetables, from root to tip, looking at the amount of fiber contained in edible parts of the plant that are typically discarded during food preparation, such as peels, skins, seeds and stems.
Fresh produce studied included beetroot, bell pepper, broccoli, butternut squash, cauliflower, celery root, kale, fennel, kiwi, leek, pineapple and watermelon.
Of these 12 different foods, the researchers found that in all but two (broccoli and fennel), the discarded plant parts had a higher fiber content by weight than commonly consumed portions — and sometimes much more.
“The variation in fiber content between the parts of foods we eat and those we throw away most was striking,” says Gibson.
“The components in our study, from root to tip, accounted for between 25 percent and 48 percent of the total product weight. This means that people are throwing away a significant portion of the products we buy.”
Of the foods analyzed, the three foods with the largest relative differences were pineapple (by weight, the skin and core together contain about 453 percent more fiber than the flesh), watermelon (the rind contains 425 percent more fiber than the flesh), and butternut squash (362 percent more fiber in the skin, seeds, and guts than in the flesh).
In contrast, in foods like broccoli and fennel, the parts we normally eat contain more fiber by weight than the pieces people tend to throw away. For example, broccoli stems contain 28% less fiber by weight than florets.
Of course, just because some of these components, from root to tip, are edible doesn’t mean they’re necessarily easy or enjoyable to eat.
The study’s big winner in terms of fiber differential, the skin and core of the pineapple, might technically be edible, but the skin may contain naturally occurring toxic compounds. The aim, therefore, is to highlight the variety of fiber-rich foods we are currently wasting.
“It’s not about encouraging people to eat ‘100g of butternut squash skin and seeds’ to increase their fiber intake,” says Balazs Bajka, a gut physiologist at King’s College London.
“On the contrary, by making better use of the often neglected parts of fruits and vegetables as part of daily meals, we have the opportunity to increase dietary fiber intake in a simple and sustainable way.”
As part of their research, the team conducted focus groups in which participants were asked about food, fiber, food waste and food preparation.
The sessions showed that although some people were aware of the fiber content of fruit and vegetable components from root to tip, their consumption could still raise concerns.
The researchers suggest that by promoting the nutritional benefits of eating from root to tip, it may be possible to further educate consumers and overcome these negative preconceptions.
“I know the skin has a lot of fiber and nutrients,” said one participant. “But yeah, uh, it’s just something about eating the skins that doesn’t really sit well with me.”
The results are reported in the International Journal of Food and Nutrition Sciences.
This article was fact-checked by Rebecca Dyer and edited by Rebecca Dyer. Although we are proud of our process, we are only human. If you spot an error, please let us know.
Gn Health
