Posteating

Posteating, or the postprandial period, refers to the interval after a meal during which the body digests and absorbs nutrients. It is a dynamic phase marked by changes in blood glucose, hormone secretion, lipid levels, and energy expenditure. The term is used in nutrition and medicine to describe physiological responses that follow eating, as opposed to the fasting state.

Physiological processes during posteating include rapid carbohydrate digestion and absorption, leading to a rise in blood glucose. In healthy individuals, this prompts an insulin response, aided by incretin hormones such as GLP-1 and GIP, which help regulate glucose uptake and appetite. Lipids from the meal are emulsified and transported as chylomicrons, contributing to a rise in circulating triglycerides over several hours. Satiety signals, including peptide YY and cholecystokinin, promote fullness. Diet-induced thermogenesis may also occur, increasing energy expenditure transiently after eating.

The time course of the posteating response varies with meal composition. Glucose and insulin typically peak within 30 to 60 minutes and decline over 2 to 4 hours in many people, though a high-fat or high-fiber meal can alter this pattern. Postprandial triglycerides may rise and peak several hours after a meal, particularly with fat-rich foods. Individual factors such as age, body weight, activity, and metabolic health influence these responses.

Clinical relevance centers on postprandial glycemia and lipemia as indicators of metabolic health. Abnormal posteating responses are associated with diabetes, cardiovascular risk, and obesity. Measurements include postprandial glucose or mixed-meal tolerance tests and assessments of postprandial triglycerides. Diet and lifestyle interventions often target posteating responses to improve overall metabolic outcomes.