Vegetarians who don't like vegetables or pulses, or most other common vegetarian food, so seem to exist on things like chips and cheese sandwiches so are impossible to cater for or find a suitable restaurant for when eating out.
Adults who are fussy about food and eat a limited diet without good reason (allergies).
People who say they 'cannot afford vegetables' but seem to have plenty of money for fizzy pop, takeways and expensive mobile phones.
People that only eat shitty food.
People who drive very short distances (less than a mile) and are generally very inactive and then complain that they 'cannot lose weight' or don't know why they keep putting weight on.
People who drop litter, especially if it is from their cars.
People who sit in car parks with the engine running.
I'm not sure if I would judge the people eating pies with a teaspoon mentioned upthread. On the rare occasion I try to eat a pie or pasty outside the comfort of my own home (eg in the car or street) I seem to end up dropping half of it on my front, so they appear to have come up with a solution to avoid such a problem.