Final answer:
Fibrous foods contribute to a sense of fullness and satiety due to their effects on gastrointestinal transit and nutrient absorption, with soluble and insoluble fibers playing distinct roles. These fibers, along with the digestion process and fat-induced satiety hormones, signal the hypothalamus to regulate eating behavior.
Step-by-step explanation:
Fibrous foods result in a sense of fullness and contribute to satiety by affecting the gastrointestinal (GI) tract and the absorption of nutrients. Fiber is a complex carbohydrate that is partly indigestible and plays a critical role in maintaining GI tract health.
It adds bulk to the diet and can create a feeling of fullness without adding excess calories. Soluble fiber absorbs water to form a gel-like substance, which can slow down digestion and extend the feeling of satiety. Insoluble fiber adds bulk and can help food pass more quickly through the stomach and intestines, signaling fullness to the brain.
The digestion process itself, involving the passage of food through the GI tract, sends satiety signals to the brain, as do increases in blood glucose levels following a meal. Fats also promote satiety by engaging different physiological responses, including the release of satiety hormones such as leptin from fat cells.
These multiple mechanisms work together to regulate eating behavior, preventing overconsumption of food by signaling the hypothalamus in the brain that the body has consumed enough energy.