Hi from Australia!

I would love some tips/feedback on my after dinner "snacking" problem. I go so well throughout the day. Do a workout, drink heaps of water and eat healthy food. But when it come to the evening, sitting down after dinner and watching tv, my body goes into snack mode. UGH! Feels like I undo all the hard work ive done during the day. Whats wrong with me? Wheres my willpower? I dont know, it just seems to disappear. Any advice would be appreciated! Cheers, Kaz