Yes, you do have to get it in!
I'm finding it much easier to stay on the diet when I have to lug my lunch to school, and then get back exhausted and with homework. I'll just do all my meal prep/planning on weekends.
I lug my lunch to work...but then I sit at a desk all day.
My main problem is in the evening, though. Hard to break habits of snacking while watching movies, reading, etc.
But drinking water helps. Maybe that's part of why it's pushed so much.