have you seen the Eat Fat book by Trudie Deakin?
She is a dietician, so everything in that book is a perfect blend of extensive dietician knowledge and LCHF. She trains other trainers.
As for worrying that you aren't eating enough... are you eating regularly? Enough to feel full? Are you eating enough volume, with enough varieties of different foods to give varied nutrition?
Broadly speaking, my personal gauge on this would be:
low carb (anywhere from 20g upwards, from low carb sources, mainly veg,
at least 5 portions a day)
enough protein (there is a calc on the number of g of protein for your weight, I will post a link)
then fill up on fat til you aren't hungry any more.
That way you simply can't not eat enough, even if losing weight, you still get the nutrition you need, and can tinker with calories and fat til you control your weight.
I know that my experience is that as soon as I wasn't wasting intake on empty carb calories, my veg and nutrition intake went through the roof! I usually have minimum 6-8 veg portions a day (although sometimes it is only 3-4 types of veg a day, in HUGE portions), with 2-3 portions of berries a week. The more varied, colourful and interesting, the better.
Here is that LC nutrition calculator:
http://www.phlaunt.com/diabetes/DietMakeupCalc.php
