Every day, no matter what is going on, my child does this thing, and then I always know what's coming next. She wiggles from the bedroom where's she's been pretending to be a ninja for the past two hours and says, "Mooooooooom..."
"Yes?" (And I know what's coming because she says it)
And what used to ensue after this comment was a fifteen-minute conversation about what she did and what she didn't want to eat. It became too much and decided that I wanted to streamline her afternoon snack so that she only had 2-3 options from which she could choose.
Long story short, I compiled 14 snacks that she loves and I rotate them each week so I know she is eating a diverse plate of food. And the best part is that she knows what her options are and that nothing else is available. Problem solved.
Since you may be struggling with a kid who doesn't know what he wants to eat, or hell, a kid who knows what he wants to eat, but you aren't offering it, I wanted to give you my list of kid-approved snacks.
And while these snacks are geared toward kids, you could totally make them for yourself to take with you for work. I broke these up based on calorie load: 100 calories, 200 calories, and 300 calories.
Some of these may seem very un-kid, but I swear that if you feed your child food and insist that you have nothing else, then eventually, you will win the war. Avoid cookies and crackers and other shit and just feed them delicious, healthy food. And of course, the calories are eye-balled here, so don't take my information as medical advice :)