I believe entirely in having a healthy mind and a healthy body, and sometimes what makes a healthy mind doesn't make a healthy body. But it's okay to indulge in moderation. How happy would you be turning down everything vaguely unhealthy 100% of the time? Easter, Christmas, birthdays, parties?
It's about having the motivation and control to know when it's not going to make you feel any happier having that second helping of dessert, but rather it's going to make you feel unhappy because you knew you didn't need it.
After times like Easter it's sometimes good to have something like a mini detox to get you back on track again. Even if that just involves doing that little bit more exercise than usual or tweaking your diet for a few days (eg avoiding anything processed).
Looking after your mind and maintaining a positive attitude will help you achieve your health goals, but try to have the things that make you happy but aren't necessarily good for your health (like chocolate) only in moderation.