so what is the science behind all this hunger?

Following this! I'm 9 weeks and can't make it an hour or two without eating, even all night long. I miss my normal days and sleeping at night. Praying it doesn't last the entire pregnancy or I will be the size of a whale. 

You can control it quite easily by eating small healthy protein rich meals with complex carbs every 2 to 3 hours.

Sadly it doesn't go away 😒 I eat constantly and I'm the third trimester the only time it's slows down is when I get sick😒