A net weight loss of 5.1 kilograms, achieved through energy restriction, increased physical activity, or both, causes a reduction of 4.44 mm Hg in systolic blood pressure and 3.57 mm Hg in diastolic blood pressure in overweight and hypertensive adults.

Losing weight reduces fat tissue, which lowers the overactivity of a hormone system that tightens blood vessels and causes the kidneys to hold onto salt and water. This system becomes less active, so blood vessels relax and the body gets rid of extra salt and water. At the same time, the body becomes more sensitive to insulin, which stops the kidneys from holding onto too much salt and reduces nerve signals that raise blood pressure. Together, these changes lower blood pressure.