Be the change you want to see in your environment. In my country everybody brings heavy cakes, pastry and coke-like drinks for birthdays. And everybody complains it’s too sweet, and ruining their figure but eat it anyway out of conformity. And you do have 1-2 birthdays per week, plus other happy occasions, like somebody leaving the company, getting married, having a baby etc. What I did: I brought exotic fruits and icecream (sorbet). The fruits should be peeled and cubed for easy access. they can mix it in with the low cal icecream or eat as such. It caught on, and many colleagues embraced this as a more healthy alternative.