Yikes. It's so disappointing to see public health agencies pushing medical misinformation but that's nothing new for the NHS, I guess. In reality if you look at this from an evidence-based medicine perspective what really matters is not the quantity but rather the osmolality. And the optimal level depends on multiple factors including genetics and activity level.
Source: https://www.nhs.uk/live-well/eat-well/food-types/salt-in-you...