Working in an office setting there are constantly doughnuts, cakes, treats, and sugar bombarding me from every department. People feel good about providing these delicious treats but sometimes fail to see the negative side of doing so.
My will power for the "cherry dump cake" sitting on the counter usually only lasts for 4 hours so I desperately hope it disappears before the 15th time I have to walk by it. I am working on this with every mental trick I know; blocking line of sight with a cardboard box, telling myself it can't be that good, and sometimes, even transporting it to another floor.
One thing I have noticed is that it offends people when I say no to accepting their sugary treats. Although my main motivation is weight management I have found it easier to evade these awkward situations by explaing my strong hereditary trend towards diabetes. I am not diabetic, however this tactic makes sense to people. They immediately understand and make an effort to not offer it to me in the future.
SO here is my tip. Don't be afraid to use a little health scare tactic in your refusals. If someone says something like "oh come on, one doughnut is okay, you deserve it!" having an answer geared around a real fear, not just weight loss, helps people to grasp the severity of one little harmless doughnut.
Stay strong, the devil is in the doughnuts.