I’ve been in advertising for 16 years and have yet to work at a place where I couldn’t take a 10 minute walk most days. People know how to get a hold of you—email, Slack, voicemail at your desk phone—and it’s nobody’s business where you go when you’re not at your desk. You could be in the bathroom, in a meeting, chatting with your boss. If anyone gives you grief, tell them you have back pain and your doctor recommended you get up and move around every so often since you sit all day.
For people eating, I recommend headphones. The big, obvious ones that go over your ears. People will think you’re just focusing/brainstorming. For hunger, try coffee or herbal tea.
I once had a boss who would go all day without peeing because she went from meeting to meeting and said she didn’t have time to pee. And everyone saw right through her—she just had bad boundaries and wanted to feel indispensable. Take your walks. People will probably join you—then you can say, “Oh yeah, Sam and I brainstorm better when we’re walking around.”