Indian astronaut Shubhanshu Shukla, who returned in August 2025 after visiting the International Space Station (ISS), shared an engaging video tutorial on eating in space. The Indian Air Force pilot explained the unique challenges astronauts face with food and drink in zero gravity. In his Instagram post, Shukla demonstrated survival techniques like "eating water" and emphasized the importance of being mindful to avoid creating a mess. He highlighted that digestion functions normally in space thanks to peristalsis, a gravity-independent process involving muscle contractions that push food through the digestive tract. The video captured widespread attention online. Nutritionists confirmed that while astronauts can digest food without gravity, they encounter specific issues such as gas mixing with liquids, leading to discomfort sometimes called "wet burps." Shukla's insights offered a rare glimpse into daily life aboard the ISS and the body's remarkable adaptability in weightlessness.
How the Body Digests Food Without Gravity
Shukla explained that peristalsis enables digestion in space. This process involves rhythmic contraction and relaxation of muscles that move food through the digestive tract, independent of gravity. Dr Anjana Kalia, an Ayurvedic doctor and nutritionist, confirmed that additional physiological mechanisms support digestion. Digestive enzymes from the stomach, pancreas, and small intestine break down proteins, fats, and carbohydrates. Bile from the liver emulsifies fats for easier absorption. The small intestine absorbs nutrients through specialized structures called villi and microvilli, relying on chemical activity rather than gravity. However, astronauts face unique challenges: gas bubbles mix with food and liquid, making burping difficult and sometimes causing bloating, indigestion, or nausea—termed "wet burps." Despite these issues, nutrient breakdown and absorption remain efficient with a balanced diet.
Source: Link