As usual, the bossy ascetics are wrong. Recommendations for normal, healthy adults to keep their sodium intake under 2,300 mg/day are not just unrealistic for most people, but probably unhealthy. According to a paper in Am J Hypertension:
Population-wide opportunities to reduce the burden of cardiovascular disease (CVD) would be beneficial. To that end, sodium reduction is recommended based upon the hypothesis that sodium restriction, by lowering blood pressure, would prevent heart attacks and strokes. To reach this goal, the Institute of Medicine (IOM) in 2004 defined a tolerable upper sodium intake level (UL) of 2,300mg/day and an adequate intake level (AI) of 1,200–1,500mg/day. However, these definitions were inconsistent with IOM’s own definition of AI, which is “the approximate intake found in apparently healthy populations.” Because the mean intake of sodium in populations ranges between approximately 2,700mg and 4,900mg, conventional estimates of AI and UL would have been similar to these values. The fragility of the 2004 UL of sodium intake (2,300mg/day) has been highlighted by the 2013 IOM report based on studies that directly link sodium intake to morbidity and mortality, which concludes that the population-based health outcome evidence is not sufficient to define a UL for sodium. An AI was also not defined.
Sodium reduction, moreover, produces several physiological effects, some of which may adversely influence health outcomes.
(Particularly galling is the description of that 2,300 mg figure as an “upper tolerable limit”. Perhaps they are using the word ‘tolerable’ to mean something other than its conventional meaning.) After meta-analysis of 25 published studies they conclude:
Both low sodium intakes and high sodium intakes are associated with increased mortality, consistent with a U-shaped association between sodium intake and health outcomes.
There are probably a great many things you could substitute for sodium in that sentence and have it remain essentially true: fat, coffee, carbohydrates, protein, chocolate, wine, green vegetables, you name it.
For its part, the CDC stands by its recommendations.