A compromise would be something like spinach. You can make spinach/kale cupcakes and apparently people like them, though I don't. Hide all the green inside and then watch their faces when they take their first ever bite of vegetables. Or do what I did once as a kid and take advice that you can replace bicarb soda with baking soda, add a huge amount of baking soda, and produce the worst tasting biscuits you have ever had. If you keep bringing disgusting "sweets" to work often enough, eventually you will train the fat to say no to food.