Weight loss exceeding 5 kilograms results in significantly greater reductions in systolic blood pressure (−6.63 mm Hg) and diastolic blood pressure (−5.12 mm Hg) compared to weight loss of 5 kilograms or less (−2.70 mm Hg systolic, −2.01 mm Hg diastolic), indicating a threshold effect for clinically meaningful blood pressure improvement.

When a person loses more than 5 kilograms of body weight, fat tissue shrinks, which turns down the activity of two systems that normally raise blood pressure: one that constricts blood vessels and holds onto salt, and another that speeds up the heart and tightens arteries. This causes blood vessels to relax and the kidneys to flush out more salt and water, which lowers blood pressure more than smaller weight losses.