As referenced by beejiu elsewhere on this thread[1], it applies to all foods products based on their nutritional content; there are no exemptions. Alcohol, however, does appear not to be covered by these new rules, but there are existing restrictions about advertising alcohol - [2] is one document on the topic, although I can't immediately tell if it's out of date.

[1]: https://news.ycombinator.com/item?id=42360734

[2]: https://www.asa.org.uk/static/uploaded/d3683dc1-189e-413c-86...

Advertising alcohol to children is, of course, already illegal.