Having breakfast, lunch and dinner are important things to remember. But what human behavior that leads to eating disorder? Is escaping one meal of the day will result to eating disorder?

    

No, skipping a meal is not considered a disorder.
It becomes a disorder if it is harmful to health.
If you skip one meal, there is no real difference that is made to your health.

If you want to find the exact definitions of the different types of eating disorders, please look at the Diagnostic and Statistical Manual of Mental Disorders. This book is used as the guidelines for mental health practitioners when they are making a diagnosis. It will have all the signs and symptoms of an eating disorder.

Skipping one meal a day doesn't lead to a disorder. There are many people who skip breakfast but they are not considered to have an eating disorder. A person with a eating disorder doesn't have to be anorexic. Somebody who is anorexic is a person who fears gaining weight. They look at themselves in the mirror and all they see is a big fat slob when in reality they are thin. In order to lose the weight, they stop eating.
There are also those who are bulimic. They also have a fear of getting fat (and they see themselves as fat) but they have no control over how much they eat. They will binge eat and then vomit it out. I've known people who have eaten cakes and pizzas, candy, chips all in one sitting and then they go and vomit it out.
There are also those binge eaters who are called Compulsive overeaters. They eat large amounts of food but these people don't vomit.
I think different factors cause eating disorders. Some people are bullied about their weight. They might start of trying to lose the weight naturally but after seeing no results they eventually turn to bulimia or anorexia. Some people might have parents who push them to be thin, while others just have bad self esteem and think that being thin will help them feel better about themselves so they starve themselves. Others might be pressured into being thin at work (movie stars, models).

I'm a weird eater, and I've never had three square meals a day. I "graze eat" throughout the day and end up having about six small meals. I don't have an eating disorder; I just don't like the feeling of eating a lot of food at once.