What does it mean that I get really tired after eating? I'm pregnant.

It may be your diet. Whether you are pregnant or not, digesting food requires an investment of energy and a shift of blood to the intestines. The content of the meal can affect the energy required. I think everyone has experienced the desire for a siesta after a high fat meal. When you are pregnant, you are all ready experiencing increased energy demands, add a meal and you get really tired.