King’s College London study finds fruit and vegetable scraps are high in fiber

A study conducted by researchers at King’s College London, published in the International Journal of Food Sciences and Nutrition, reveals that the peels, stalks, seeds, and cores of many fruits and vegetables contain significantly more dietary fiber than the parts typically consumed.

Analyzing 12 common types of fresh produce, researchers found that discarded parts contained higher fiber levels in 10 of the 12 cases. Notable findings include pineapple skins and cores containing approximately five times more fiber than the flesh, and butternut squash skins and seeds providing 9.25 grams of fiber per 100 grams. Watermelon rind was also found to contain 2.10 grams of fiber per 100 grams, comparable to a slice of wholemeal bread.

The research highlights a potential solution to two major issues: low dietary fiber intake and high food waste. In the United Kingdom, only 4% of adults meet the recommended daily intake of 30 grams of fiber, with an average consumption of just 16.4 grams. Additionally, the UK wastes approximately 10 million tonnes of food annually, with fresh produce accounting for over a third of that volume.

Lead researcher Dr. Rachel Gibson noted that discarding these parts represents both a nutritional and economic loss, as these scraps can account for 25% to 48% of a product's total weight. Experts recommend a “root-to-tip” eating approach to improve digestive health and reduce waste, while emphasizing the importance of thoroughly washing produce before consuming peels or skins.