*3.3. Changes in Sodium Content over the Years*

When sodium content was compared over the years, some differences were observed. Foods from 2020–21 had the highest sodium content (Table 5). This may be due to different kinds of foods collected over the years. In order to minimise this confounding factor, a comparison was performed by food group. Only those with at least 30 items from three different brands were considered for this analysis (G6, G7 and G13 did not meet this requirement). Groups with no added salt (G9, G10, G12) or high heterogeneity (G11) were also discarded.

*Nutrients* **2021**, *13*, 3410


**Table 5.** Comparison of the sodium content (mg/100 g food) by group and

 year.

of foods. 25th, 50th 75th: percentiles. ND: Not Determined (<30 foods or <3 brands).

As seen in Table 5, G4 (cheese), G5 (dairies and substitutes), G8 (meat) and G14 (sauces) showed statistically significant increases in sodium content in 2020–21 compared to 2017–19. No tendency to decrease sodium content was observed for any group analysed.

Further analysis was performed by comparing the same products over the years (matching products). A total of 219 foods could be studied, from 29 different brands and belonging to 12 groups. No differences were observed in sodium content (mean sodium differences = −7.1 mg/100 g; median sodium differences = 0 mg/100 g; 25th and 75th were also 0 mg/100 g).

#### **4. Discussion**

The present work analyses 3897 foods sold in the Spanish market from 2017 to 2021. Sodium content depends much on the food group. A low proportion of foods were sodiumfree and almost half of foods were low in sodium. A high proportion of foods were considered high in sodium according to the two NPMs used. Both NPMs greatly disagreed in some food groups. No decrease in sodium content was observed over the years.
