The US Department of Health states that approximately 2000 calories is required for the average person with a normal to active lifestyle to remain healthy. The diet should be balanced between fruits, vegetables, proteins, dairy and grains.
As for fertility, whitebois don't get fertility. But then, black men don't either. Men are VIRILE, and females are FERTILE. I wish people would learn that difference. Virility can be modified by diet. There are foods that are testosterone-inhibiting, or even estrogen-enhancing.
Cleanliness would be mandatory for someone with a restricted diet. The body requires calories for muscle, skin and nerve development, injury recovery, and to cleanliness would need to be mandatory to help the body maintain good health. Depending on the work being preformed, you would need a shower perhaps 3-times per week, or daily, depending on the activities. In addition the quarters you would be living in would similarly require cleaning on a frequent basis, as the dead epithelial cells and natural oils and fluids from the human body tend to breed bacteria that can be very harmful to us. Scratches and scrapes would become infected and require treatment and more calories to heal. Cuts would be the same, only more.
So start there and think it through. Being a slave isn't all it is cracked up to be.