I read somewhere recently that you don't need any extra calories in the first trimester of pregnancy, though I don't recall seeing that anywhere else I've read about nutrition in pregnancy.
My theory is the typical tiredness must come from somewhere, it's probably some kind of indication of the work our bodies are doing.
I also read an article yesterday about people who find it difficult to put on muscle bulk, despite working out. In someways I fall into that category, any greater muscle definition I've gained in the past few months comes from losing weight I gained post hip surgery, despite the fact I've been doing quite a lot of exercise. Not that I've been aiming to gain muscle bulk, but it was interesting to read how you could see if you fell into this category and what the potential reasons might be. Fundamentally it seems I probably don't eat enough, or not of the right kinds of things.
Having had one growth restricted baby, I do want to make sure to eat well throughout, growth problems in the uterus aren't well understood, later on it's thought to be a placental problem and the baby simply can't get enough regardless of what the mother eats, but early on the placenta is still being formed and if eating the right amount of stuff can influence that, then it's something I want to do. But when you're feeling sick a lot of the time, getting enough to eat is challenging, particularly as high protein foods are some of the least appealing for me right now.
I've never been a big milk drinker, but one of the things I did when expecting DD was finding ways to sneak milk into my diet, back in the UK, I ate a lot of Angel Delight, it's an instant dessert that you whisk with milk then leave for 5 minutes. Right now I'm going for hot chocolate with whipped cream. Another advantage to this is that we have vit D enriched whole milk.
There is one caveat that I only just realised, with Sausage Boy, I stuck to my usual very low milk diet (about a half pint or less per week) and he's had no problems with milk. With Banana Girl, she's borderline intolerant to the stuff, we never had a problem when she was breastfeeding, but she gets very mucousy when she consumes too much, but as it's not a complete intolerance or allergy it's not really a big deal, she has soy milk on cereal and occasionally to drink and doesn't appear to miss regular milk, she sometimes has chocolate milk, but doesn't seem to like it that much, just does it to copy big brother. Milk that's been processed such as cheese doesn't seem to bother her. You have to wonder if this is connected, it does seem anecdotally that it's often the mothers who are big milk drinkers who have babies with milk allergies!