Make healthy treats for a dieting friend

To avoid irreversible offense/trauma/ill will, you should be absolutely sure before proceeding that this person is on a diet. And this information should be volunteered by the dieter, not asked by you. This is crucially important to maintaining friendly relations. There's a wealth of online resources to help you. A list of main dishes can be found here, for example. For sweets, this is a list of substitute ingredients for making baked goods more nutritious. 


Or if you break out into a cold sweat at the idea of using your oven, you could always pick up dried fruit or make single-serving snack packs. This is as easy as portioning chocolate, nuts, crackers, roasted chickpeas, jerky, etc. into reusable bags. The appreciation you'll get will outweigh the effort you put in.


Effort involved: as indicated above, disproportionately low considering the praise you'll receive.