White potatoes have recently been allowed back in the cash value voucher of the government food stamp program after it was stated that there were no known adverse health effects of potatoes. However, the association of potatoes with heart health, especially elevated blood pressure is not known. This study will examine the effects of potatoes on blood pressure in different populations of adults and children, and assess, in a feeding trial, the effects of an additional serving of potatoes per day on the possible mechanisms that link potatoes to high blood pressure. The investigators will also analyze the intake of potatoes in participants of the government food stamp program.