First - is that if you give someone an Unbestowed Frienship Bracelet to fix their Heartbroken Status, you receive a "Gift of Friendship" Buff which gives you +200 to Health (This is separate from the /kiss Kwee +200.)
Second - The chocolates can be eaten and you can receive multiple effects at the same time. The screen shows all of them are active, but I haven't tried to test the accuracy of this. (Let me know if anyone has.)
We used to be able to eat multiple pieces of food and recieve all the buffs at the same time. However, that was changed in Patch 1.9.
Food and Drink are now in separate categories, so you can only have one food effect and one drink effect on you at a time. The only effect should be that foods that used to stack with each other (you could have two food effects on you at once) no longer will stack.