Pause for a moment and consider the answer to this question. If you're truly hungry, eat! Your goal isn't to eat less, but rather to stop eating when you aren't hungry.
Focus on using food for its intended purpose: nourishment. We'll deal more with how eating is connected with emotions in tomorrow's challenge, but for now, just focus on whether or not you're hungry.
If you find that you're not actually hungry, consider getting a glass of water or a cup of tea and putting off your meal for a bit — you might just be thirsty. Or, it may help to do something to distract yourself for a few minutes, like taking a short walk or doing a brain teaser.
I frequently mistake hunger for thirst. To avoid this, I keep a large glass of water nearby and drink throughout the day.