Postprandial hypotension is a drop in blood pressure that occurs after eating, most often within the first one to two hours after a meal. It is linked to the normal movement of blood toward the stomach and small intestine during digestion, combined with an inadequate cardiovascular or autonomic response. After food enters the digestive tract, blood flow increases to support gastric emptying, intestinal absorption, pancreatic hormone release, and nutrient transport. In a healthy response, heart rate, vascular tone, and hormonal signaling adjust to maintain stable blood pressure. When these adjustments are delayed or insufficient, blood pressure can fall and may be associated with lightheadedness, weakness, fatigue, blurred vision, imbalance, or post-meal sleepiness. Meal size and meal composition strongly influence this pattern. Large meals, rapidly absorbed carbohydrates, low-fiber refined foods, and highly concentrated glucose loads can increase splanchnic blood pooling and intensify insulin and gut hormone responses. Fast gastric emptying may deliver carbohydrate quickly into the small intestine, producing stronger glucose absorption, incretin signaling, pancreatic insulin release, and vascular changes. These events can interact with autonomic regulation, endothelial nitric oxide signaling, renin-angiotensin activity, vasopressin signaling, natriuretic peptide signaling, and hydration-electrolyte balance. A whole food plant-based diet can support meal composition by emphasizing smaller, balanced meals built from intact carbohydrates, legumes, whole grains, vegetables, fruits, seeds, and water-rich foods. These foods provide fiber, resistant starch, potassium, magnesium, polyphenols, carotenoids, and amino acid substrates that slow glucose absorption, support endothelial function, strengthen gut microbiome short-chain fatty acid signaling, and help maintain hydration balance. Foods such as brown rice, oats, lentils, chickpeas, black beans, quinoa, sweet potato, spinach, banana, blueberry, flax seeds, and green tea provide gradual carbohydrate delivery and biologically active compounds linked to vascular and metabolic regulation. Meal pattern is also important. Smaller portions, slower eating, steady hydration, and pairing whole grains or starchy vegetables with legumes, leafy greens, berries, and seeds may reduce rapid post-meal glucose appearance and support more stable blood pressure physiology. This plant-based approach does not rely on stimulants, animal foods, oils, or processed meal replacements. It focuses on intact food structure, mineral density, fiber viscosity, polyphenol exposure, and digestive pacing to support the body systems involved in post-meal blood pressure stability.