Hypertension is a leading risk factor for cardiovascular disease (CVD) globally, accounting for 25-35% of the population-attributable fraction. Sodium (salt) intake is a key determinant of blood pressure, and reducing sodium intake has emerged as an important target for population-based interventions to prevent CVD. However, there is considerable uncertainty about the optimal level of sodium intake that is associated with lowest CV risk, and whether optimal levels differ for different populations and individuals. International and national guidelines recommend low sodium intake (<2.3g/day, or lower) in all persons, and advocate a population-wide approach to reducing sodium. Most of the world's population (~95%) consume between 3 and 6g/day of sodium (mean intake 4.0g/day), which means that most people will require a major change to their diet, to achieve the guideline target (<2g/day). While there is convincing evidence that high sodium intake (>5g/day) is associated with an increased risk of CVD, compared to low or moderate intake, the evidence that low sodium intake (<2.0g/day) is associated with a lower risk of CVD than moderate intake (2.0-5g/day) is inconsistent and inconclusive. The investigators plan to conduct a Phase IIb clinical trial to evaluate the role of low sodium intake (versus moderate) on cardiovascular biomarkers.