Oh man, how many times have you heard this? "Have an extra helping, you are eating for two!" OR "You are so lucky, you can eat anything you want now because you are eating for two!" OR "You aren't eating enough, remember you are eating for two!" Sound familiar?
This is a very hard mentality to not fall prey to while you are pregnant. It sounds very inviting. I mean, hey! I can finally eat as much as I want?! Hmmm... unfortunately, that is not the case. Yes, there is a tiny human being inside of you that does need to be fed. BUT it is a tiny human, not a full grown adult.
During your first trimester you should aim to gain around 2-4 pounds total for the entire trimester. Now, keep in mind every body is different and there are differences from pregnancy to pregnancy so allow yourself some grace here. You should be consuming around your normal amount of calories in this first trimester, maybe an additional 100 calories if you aren't feeling nauseous. If you have gained more than the 2-4 pounds in your first trimester don't panic and don't start dieting. This is not the time to start restricting your eating no matter how much you've gained. Just start paying closer attention to what and how much you are consuming. Think portion control, balance diet and variety.
Your second trimester you should be feeling better and more energized. You should be gaining on average 3-4 pounds per month. Depending on your height and weight your caloric intake will increase by approximately 300 additional calories per day. And example of 300 calories is 2 slices of whole-grain bread with 2 tablespoons of peanut butter. So keep this in perspective. Try to stay in tune with your body. When you are hungry have a healthy snack on hand. Always be prepared. Eat small, healthy portions throughout the day to keep your energy high and hunger at bay.
By your third trimester you should be continuing to gain 3-4 pounds per month. Your caloric needs may increase by an additional 100-200 calories from your second trimester. Just continue to be an intuitive eater. As your belly grows your baby will be taking up a lot of the space where your organs use to sit comfortably. So your stomach may not be able to handle as much food all at once. All the more reason to eat smaller portions throughout the day. This may also help extinguish cases of heartburn from torching your esophagus.
To wrap it up, eat for two. But remember your little eating buddy is anywhere from the size of a tadpole to a small watermelon not a 300 pound linebacker. Here's more on prenatal nutrition.