Many components in fruits are water-soluble, such as Vitamin C and soluble plant fiber—pectin, which can lower cholesterol levels in the blood. Their digestion and absorption do not require the mixing of complex digestive juices, allowing them to quickly pass through the stomach and be absorbed in the small intestine. The absorption rate on an empty stomach is significantly higher than after a full meal.
Eating fruit before a meal helps in achieving the principle of an 80% full healthy diet. Fruits are low-calorie foods, with an average calorie content of only one-fourth that of an equivalent weight of staple foods and approximately one-tenth of that of meat like pork. Consuming low-calorie foods first makes it easier to control the total intake.
Many fruits are easily oxidized and spoiled. Eating fruit first can shorten its residence time in the stomach, reducing the extent of oxidation and spoilage, and thereby minimizing any potential adverse effects on the body.