To dream that you have this disease does not have to be a prediction (although if you have symptoms of discomfort, it is worth a check). Cancer is a tumor, and the dream could mean that an undesired element is becoming part of yourself or is growing in excess; for example a growing obsession that can affect your personality, and even your health. Having cancer in dreams also indicates that you do not properly deal with your emotions which end up being destructive; the dream is a warning against that.
If you want to go on a diet, you might want to have enough of sleep. The researches show that people who are on a diet and rests well, relatively lost more fat, of about 56% than those who deprived themselves to sleep. When you sleep well, your metabolism also works well, certain hormones will go up in your blood and drive your appetite.
In most kids, lack of sleep can surely result to ADHD (Attention Deficit Hyperactivity Disorder), which is the opposite with the adults. Children between 7 and 10 who gets less than 8-hours of sleep every night will likely to become inattentive, impulsive and hyperactive. Their sleeping patterns can easily affect their brain.