Data for 311 fast food items were collected and entered into a
Microsoft Excel spreadsheet. For each product the following information
was recorded: company name, product name, serving size
(g), energy (kcal and kJ) and salt (g) content. Where information
was available, we recorded energy and salt content both per serving
and per 100 g. When both measures were not provided, one was
calculated from the other using the serving size of the item. If sodium
content was provided instead of salt, the value was converted by
multiplying by 2.5 (Institute of Medicine, 2004). The data entry
process was checked by selecting a random sample of 5% of entries
and comparing the information in our database against the original
website source.