The only one I have a hard time saying no to is myself, frankly enough. Sometimes I want to do things that I know I shouldn't. My mind says no but my body says it is so.

For someone who fasts, I have gotten ridiculously weak to food, something that I definitively must get in control.

There must also be a mention that saying "No" becomes diminished if you say "No, but....". Happens to me a lot.