For weight loss which is better eat only when hungry or on a time table?
One needs to build a very fine balance of eating on time and should train your body to feel hungry at the right time. A good practice is to speed up your metabolism. You should eat food every 3 - 4 hours. Do not eat huge amounts but have only smaller amounts of food. It takes a while for your body to get adjusted to the new eating schedule you are training your body with, but human body is very flexible and eventually adapts to it.
When you go long periods of time without eating your body goes into a starvation mode and when you do eat your body will store the excess calories as fat instead of using it as fuel to give you energy.
A right mixture of good controlled regular diet and exercise will help you great deal with weight loss.