the most recent Dietary Guidelines Advisory Committee (DGAC, 2005) also noted that inclusion of children beginning at 2 years of age is based partly on concerns about the development of taste preferences for foods with added salt at young ages. As discussed in Chapter 3, preferences for salt taste begin as early as 4 months of age and are shaped by experiences with foods. Moreover, throughout the lifespan, adaptation to lower sodium intake can occur if introduced gradually.
An additional point of controversy concerning extension of the reduction of sodium intake to the general population is the issue of salt sensitivity. This concept refers to differences between individuals in the way that their blood pressure responds to changes in dietary salt intake (Strazzullo, 2009). Although some argue that if salt sensitivity were taken into account as part of dietary recommendations, such recommendations would not need to be expanded to the general population, the major national authoritative consensus bodies have not supported the conclusion that salt sensitivity mitigates the concern for a general population approach (DGAC, 2005; IOM, 2005). There is variation in responses to changes in salt intake (IOM, 2005). However, such changes do not reflect a threshold effect, but rather have a continuous distribution (DGAC, 2005). There are no established standardized diagnostic criteria or tests, and there is no biological basis for deriving meaningful cut-points (Cutler et al., 2003; DGAC, 2005). Further, the responses are modifiable by factors such as potassium and other dietary intakes. For these reasons, there is no validated or scientifically defensible basis on which persons could be identified as “salt sensitive” or “salt resistant.” As such, the concept of salt sensitivity does not provide a basis to identify a subgroup of the total population as a target group (IOM, 2005).
Based on the consensus reports from expert advisory committees and relevant published literature, the strategies to be developed are to be targeted to the general population and consistent with the statement of task. The goal is an overall population-wide intake of sodium consistent with the levels specified by the Dietary Guidelines for Americans.
The steps followed by the committee in recommending strategies to reduce sodium intake are illustrated in Figure 1-1. At the outset, it is important to clarify key terminology. Although the term “salt” (sodium chloride) is not interchangeable with the term “sodium,” many reports use them synonymously because the most significant contributor to dietary sodium is salt. This report uses the term “salt” when the intended reference is to sodium chloride, and the term “sodium” when the intended reference is to sodium. Further, the term “food industry” is meant to encompass