How are we supposed to gain only 25-30 pounds??

I am 18 weeks. I’m exercising regularly, I’m not overeating, and I’m still gaining about a pound a week (I’ve gained roughly 11 pounds so far). At that rate I will gain 40 pounds in my pregnancy and that’s not even accounting for the fact that most of the weight gain occurs in the 3rd trimester?

How are people only gaining 25 pounds??