How unhealthy is it when one doesn't eat until dinner time?

Watch for muscleloss: If you do this on a routine basis body will get used to it. But you want to make sure your diet has balanced portions of proteins, fats and carbohydrates otherwise you might be loosing muscles to make up for the energy during daytime.

Very Unhealthy: Your body requires energy in the form of food regularly throughout the day. When you only eat late at night your bodies internal clock tries to save all this energy rather than use it up. This leads to weight gain rather than loss; and a run down feeling from low energy. Eat regularly in little doses to get better energy and weight control.

Dr Kuitems agreed