Im pretty sure you can eat as much as you want as long as your within your syns and everything is worked out in thirds on your plate.
I generally have the following in the cuboard for snacks:
Walkers Pops 4syns per 19g pack
Kellogs Fruit Winders only 1 Syn
Activia Intensly Creamy vanilla only 2 1/2 syns nice and thick and fills you up especially if you add fruit to it.
Ive started buying little packets of Frootz Buttons 3 1/2 syn a pack they are yummy
Snack a Jacks Caramel 2 1/2 Syns I think only 2 syns if you choose the cheesy ones.
My Friday Treat is a Freddo at 5 Syns but just keeps my chocolate cravings at bay.
Fruit Wise, I'm mixing it up each week instead of having the same fruit, so Ive started buying watermelon, strawberries one week and grapes and oranges the next etc.
Another Tip if you get Hungry, I go for a half hour walk and normally I'm not hungry when I get back. I think also I read somewhere that food cravings last for 20 minutes so I just try and ride them out lol
Hope this helps