Is salt really a new culprit in type 2 diabetes?

economictimes.indiatimes.com:

type 2 diabetes, they often think of sugar (even though the evidence for that is still not clear). Now, a new study from the US points the finger at salt. The study, conducted by researchers at Tulane University in New Orleans, used data on about 400,000 adults, taken from the UK Biobank study. This observational study followed the participants for nearly twelve years. In that time, around 13,000 developed type 2 diabetes.
In a press release, the principal investigator on the study said that «taking the saltshaker off the table can help prevent type 2 diabetes». But is it really as simple as that?
For a start, this type of study, called an observational study, cannot prove that one thing causes another, only that one thing is related to another. (There could be other factors at play.) So it is not appropriate to say removing the saltshaker «can help prevent».
My colleague Dan Green and I have previously criticised university press releases such as this as they can lead to misleading news stories. The Tulane study can only suggest an association between salt use and the risk of developing type 2 diabetes — nothing more.
This is before considering the quality of the data itself.
The data used to assess salt use, was based on the simple question: «Do you add salt to your food?» (It specifically excluded salt added in cooking.)
The question the participants in the study answered only had the options: «never/rarely», «sometimes», «usually» or «always». This means it is not possible to estimate from the answers how much salt might be associated with an increased risk of developing type 2 diabetes.

Processed food is the biggest source

Normal salt intake in countries like the UK is about 8g or two teaspoons a day. But