Is it OK if I remove my rabbits food from say... 10:00 PM until 6:00 AM? ?

The reason I am asking this is because I have a 10 month old Holland lop female bunny and a Netherland male bunny and I noticed that my female wants to eat constantly and she is getting quit plump and is not really active and wants to sit next to her food dish and eat, eat and eat. She has hey but tends to eat the pellets more so then the Timothy hey and I also give her a small amount of celery leafs, apples and carrots daily. I know her and my Netherland bunny seem to be awake more so at night time and I fixed up the bunny room for them with , cones to run through and hide in, big sticks to chew on, a thick fuzzy rope that hangs down that seems to keep my one bunny amused. If I take their food such as the pelletts up at night and just leave down the Timothy hey and water bottle? Do you think that is being mean or do you think that is OK? I just want her to be a bit more active. I do take her outside in to her run and she tends to do the same thing there as well. It's a good 15X8 foot run that's real nice set up for them to play in. They have toys in there just as well. I do let her run around the backyard freely as I'm always with her when she is running the backyard but only one at a time. That seems to be the only true exercise she tends to get. I do bring them in to the house each night in to the bunny room because I don't have a top on their run and I don't want the strays getting to them. Next spring my husband will build and make a beautiful weatherized hutch for them and a cover to go over their run to keep it nice and dry from the elements. If anyone has any more sudjestions to help me out with some new ideas? Please let me know. I just don't want her to be unhealthy at such a young age or for that matter any age. Thanks... :o)