If any whole country gave up candy then they'd save a lot in direct cost and even more in related costs (diabetes, etc.) that they could certainly help feed many many people. Sure, the effect of one person not eating candy is easily lost, but I spend a few pounds a month myself on sweets (ie candy, I'm from the UK). I know that money could likely feed someone in a developing nation for a month.
It's so easy to tell ourselves that each small contribution adds to zero, but as someone noted elsewhere in this thread, calculus should tell us enough to be wary of dismissing little bits!
I don't know who needs to hear this, but being overweight doesn't make someone a bad person. Flying from New York to San Francisco a couple times a year also doesn't make someone a bad person.
It's so easy to tell ourselves that each small contribution adds to zero, but as someone noted elsewhere in this thread, calculus should tell us enough to be wary of dismissing little bits!