I don't complete understand calorie counting (nor do I care for it) but from my understanding and what I have been told is that you dont need to much extra- literally like 1 apple or banana a day extra. Although I guesd that entirely depends in the person and how much you eat usually.
Lol I don't know either I just read some where where it says you need a extra 450 calories in the third trimester
1 calorie = something like 0.004kj ?
Don't know what you mean. 450 calories would be a whole meal though.