Right off the bat I'll say I didn't have a very bad case, but if I hadn't figured this out quickly it would have come and gone for months. Everyone's experience and solutions are different, so I'm sharing this in case it's helpful for the portion of people with my type of metabolism.
Even before pregnancy I was hungry in the mornings, and I found it almost impossible to fill up once I was six weeks into my first pregnancy. I remember chugging a Gatorade after I'd already had breakfast and a morning snack, and calling my mom to ask what worked for her. She said she ate every time she woke up at night and was the least bit hungry.
This turned out to be a game changer for me, but I found that not every kind of food made an equally good midnight snack. Meat wasn't so good, but fruit, nuts, and yogurt worked well. Banana cream pie was a mainstay for a while.
What I realized about my blood sugar was that by the time I was hungry, I was better off eating something carb-heavy and basically spiking my blood sugar to quickly resolve the nausea. Normally I over-react to sugar and I would avoid spiking it, but first trimester of pregnancy was different.
Once my blood sugar was up, I would immediately eat a more balanced meal or snack, still with more carbs than I would have eaten without being pregnant. As long as I did this I felt fine. After a few weeks my blood sugar and appetite stabilized or normalized, though I still had regular night snacks for the first few pregnancies. Once I was over 30 and my metabolism was a little slower, I didn't need to eat as frequently either day or night, which was convenient since I was busier. But I still kept a stash of popsicles and other favorite carbs for when I needed a quick lift.
Another part of this strategy is to rest as much as possible. I don't know why this makes a difference, but if I power through first-trimester fatigue for a day or two, I would become nauseous most of the time instead of intermittently. Other moms have noticed the same effect - the more they rest, the easier it is to manage nausea. I know it's not possible to cancel every obligation in your first trimester, or even for a few weeks, but letting the house go, and using convenience foods can help. From 6-9 weeks pregnant all bets are off for productivity, as I drag myself to the fewest possible things, nap, and go to bed at 8 pm.
I have a few friends who can't eat any extra carbs when pregnant, but the strategy outlined above has helped many people I know and may work for you or a friend.
Best of luck to all expectant ladies!