Which part of the small intestine is responsible for most food absorption?

The jejunum is the section of the small intestine primarily responsible for the majority of nutrient absorption. It comprises the middle portion of the small intestine, where most of the digested food, including carbohydrates, proteins, and lipids, is absorbed into the bloodstream.

While the duodenum plays a critical role in the initial stages of digestion—helping to break down food with enzymes and bile—the jejunum is specifically adapted for absorption. It has a larger surface area due to finger-like projections called villi and microvilli, which increase the efficiency of nutrient absorption. The ileum, while also involved in absorption, is more focused on the absorption of vitamin B12 and bile acids rather than the primary nutrients.

The answer that includes all sections of the small intestine may seem tempting, but it is important to note that while nutrients are absorbed throughout the small intestine, the jejunum is where the bulk of that absorption occurs. Understanding this distinction helps clarify the specific roles of each part of the small intestine in the digestive process.