My input it:
Eat some fish. Make sure it's ethically sourced (ie NOT haddock and cod every day, cos they're not in good supply anymore)
Sainsbury's sell only well farmed, RSPCA Freedom foods salmon. It's only come from Scotland too, and not all the way across the atlantic. You can get enough for 2 large adult portions for about £2:50. We had some for lunch on Tuesday. Just heat oven to max, and then when it's hot, put salmon in on foil, for about 6 minutes...
Eat lots of fruit. Vegetables are good... but fruit is very rarely cooked, so maintaind a lot more vit c and frankly it's easier to eat at work than a head of broccoli.
Try to have some pulses... beans. There are now loads to choose from. Flageolet, red kidney, borlotti... whatever.. just ue those to replace some meat in whatver you make. It's cheaper too... just rinse them WELL if they're in salt water.
And try to eat as many different colours as possible. If you can manage a red , a green, a white and a purple thing, you're rocking