Let them choose their own pattern of sleep..the human body eventually adapts and finds it own pattern called the Circardian Rhythm.
I have noted that many parents become alarmed even in childs eating pattern especially when the child is sick..they get scared that they child is not eating.
Its not easy telling parents that those who are sick usually eat less and appetite will be back to normal once they get better.
If we observe a sick animal for example a dog or cat..we will notice that when they are sick..they hardly eat and some cats eat grass at that time and rest the whole day..once they are well they start eating again.
I guess when we are sick the body concentrates on fighting the disease and giving the disgestive system a rest like a semi fasting state....but dont ever try telling a human parent to observe cats and dogs cos they will shout back at you saying "my child is not a dog or cat"
So you will have to be the very careful on how we word it ..we can say that "in all mammals..humans and even the canine and feline family...when they are sick the GI system usually goes into resting mode blah blah blah"