OP, I once posted that I was cross with my FIL for "forcing a chocolate button" down my poor 7 mth old daughter... I was almost laughed off mumsnet.
One thing I want for my daughter is for her to have a healthy relationship with food. I went through some very bad times with my relationship with food, from throwing up, taking laxatives, hiding my food etc. It took me a long time to get over it, even though it was never really that "serious". So it is important for me that DD has a good relationship with food, and that means that she gets to have treat food.
She quite likes chocolate spread on crumpets for breakfast. Which I found out that she'd had one morning at the childminders, and rather than flipping out, I thought of all the healthy meals that she has, the healthy snacks etc. She loves fruit and vegetables (she'll be three in October), she loves cheeses and yoghurts, she eats really well.
So when we go to my mum and dads and they give her puddings, or we go to the inlaws and they give her sweets, I remind myself that they are a small % of her actual diet.
HTH!