I always make sure I make an extra portion of the evening meal to have for lunch the next day. Although I am lucky to have a microwave at work.

Next weeks menu plan is as follows and each day with the exception of Wednesday I will have leftovers for lunch the next day:
Sunday: Campfire Stew
Monday: Pasta Arrabatia
Tuesday: Fajitas (I stick it on top of a Jacket whilst the rest of the family have wraps)
Wednesday: Jamaican Chicken
Thursday: Chilli

I then make up a salad to go with it at lunch, if there aren't enough veg in the actual dish.
Fruit wise, I make a nibble pot each morning with whatever fruit I have Melon, Pineapple, apples, pears, grapes (NO Bananas!! they go slimy). My Fave is a whole grapefruit and whole orange segmented, I could eat that all day.

Doesn't sound like you eat enough for lunch. Getting a list of good lunches , as suggested above, then getting organised the night before in making them up will really help you. Prevent getting caught out. Look up low syn foods from the supermarkets that you have access to, asda tinned Dahl for instance.

Good luck, let us know how you get on.

I've had the tesco healthy choices cottage cheese on jacket potatoes for my lunch most days