Try eating dried fruit like dates, figs, raisins, combined with nuts daily. You will be full faster but your body will need some time to adjust and for the first couple of days you may crave even more and the extra fiber might give you the runs a little, but it will pass.
Also try adding curry powder to nuts, put in a jar and shake it up, great alternative to crisps and such.
Adding beans to your salads will help too. Be careful with starchy carbohydrates like potatos, pasta, bread and rice. Your blood sugar rises and drops which makes you hungry faster. So keep those to a minimum and make sure it's all wholegrain at least. Dried fruits have lots of carbs too but the fiber keeps it from entering your blood too fast.