The 35-year-old superstar mom says she loves preparing meals for her young brood but it can be a tricky task.
"The problem with my packed lunches is everybody is very outspoken about what they want, so I often say, 'I'm not a waitress!'" the actress told the British morning show GMTV this week.
The Oscar winner, who is currently in Europe promoting her action thriller Salt, says their shopping list is only going to grow.
"We go through so much food," she complained. "And they're still little. So, I can imagine it's going to get worse."