HELP!

I need to lose weight. I need to eat a more healthy diet with less sweets - a bowl of icecream is NOT lunch! I want to be alive and fit when I am 65 - I want to avoid as best I can having my Mum's health at 65 - I want to be like my MIL who kept a cracking pace up at the zoo the other day with her 5 grandchildren, 2 DILs and her US exchange student. I need to change my sweet tooth now! I actually eat quite well for breakfast and dinner. We get curry every Friday from our favourite Indian restaruant but other than that the only take away is an occassional pizza or perhaps a platter of lebanese food. No it is lunch and afternoons where the wheels fall off my wagon. I just don't feel like eating much! and then I get hungry and need a sugar hit ... Any ideas for a variety of easy but tasty lunches? I think I can do fruit for afternoon tea but lunch has me stumped I don't want to rely on sandwiches.

I already exercise a fair bit - running after the brats - that can be increased a little without too much effort. It would be nice to actually enjoy getting dressed again!