Do you mean eating out at fast food places and such at night? If so, then I believe it's riskier. Many criminals use the darkness of night for cover, and most restaurants have little in the way of security. If you're going to eat out late, I'd at least take a pocket knife or pepper spray for protection, and try and stay in a group. You never know when you'll need it.
Nutritionally, it's also not recommended to eat late; food metabolizes poorly during sleep. Many experts recommend you finish dining for the day between 6 and 8 p.m.