Baby movements

Rachelle • Mother to 3 daughters and 3 sons. Mother to 3 angels taken early in pregnancy. Currently pregnant with my number 7.
So I'm 18 weeks pregnant today and have felt baby move from about 14 weeks. These movements kinda last for like a day or two a week. Then nothing for the remaining days. I don't eat very much. Heart burn and the fact I'm not hungry makes it really hard for me to want to eat so I usually snack during the day and eat dinner. But some days I will just eat dinner. What I was wondering was this.... 
Can lack of food or nutrition cause my baby to be less active? To not move. 
I can't wait to hear from you all and get advice. Thankyou