The questions;
The congestion questions only offered one solution, which I happen to think is the wrong solution anyway.
The best solution I have seen and used is park and ride.
This could be refined by having a charge to enter a restricted area but pre booked, no booking then no entry, or large fine, (providing signage made that clear) booking via phone, internet, local shops.
This way it is possible to have some exemptions, after all the point is to reduce traffic not stop it.
The food question:
Taxing food is not effective, the problem I think, is caused by manufactured foods, therefore limit or prevent their production.
Evolution has left us with weakness for fat, sugar, and salt.
Way back, (stone age and before) we lived on a wide range of leaves, grains, fruit, and roots, with very occasional animal flesh, collecting food was a fulltime job.
Salt, unless we lived near the coast, (coastal plants are adapted to hold salt in special cells) salt was hard to find, so we are attracted to salt, when we found any we ate it.
Sugar, was a rough indication of 'safe to eat' (bitter is risky) but it also takes very little effort to convert sugar to energy, if we find sugar then, eat lots.
Fats (vegetable or animal), much more energy than carbohydrates, therefore much less effort to fill yourself, and less work.
Getting food was hard physical work so the risk of getting fat was low.
Fats and sugar can be mixed easily, salt can make some fats more palatable, all adding up to what food manufacturers produce for us, and it's no effort to get food we just need money.
For anyone interested, BBC 4 2024 Christmas Lectures can be found on iPlayer 'The Truth About Food'. 3 x 1hr.