Despite the jargon use of the term, I don't think dog food CEOs actually eat their dog food, because it is for dogs. Similarly Reddit is for Redditors.
I'll just point out that dog food is food. It may not be healthy for a human in large amounts, but it can't be worse than eating fast food for a week or so.
I know an unreasonably large amount of people that claimed to try it. Most when they were children. I doubt that my bubble is unusual on this.