Have you ever wondered why some diet plans are effective to some while a failure to others? That's because there are many kinds of obesity according to a Harvard professor.

Dr. Frank Sacks, a professor in nutrition at Harvard University, said that obesity is like cancer which has many types. That is why even if two people have the same fat excess, same age, same gender, and same socio-economic status, they cannot have the same treatment.

Dr. Lee Kaplan, director of the obesity, metabolism and nutrition institute at Massachusetts General Hospital, has counted that they have found 59 types of obesity so far. With that discovery, he then reasoned out that since obesity has many faces, it does not make sense to recommend just one way to prevent it. To say that you can get rid of excess fat by doing one thing is like recommending to someone with lung cancer to stay away from the sun, which applies only to those with skin cancer.

Another research by the Department of Clinical Biochemistry and Medicine at Cambridge University headed by Dr. Stephen O'Rahilly, said that his team has found 25 genes that greatly impacts weight gain when they mutate.

In the same way, there are also types of drugs that cause weight gain. For example, drugs for diabetes, high blood pressure, or steroids that suppress the immune system, can contribute to weight gain. People who take such kinds of drugs might not realize that these are the cause of their weight game and not because they have lack of self-discipline.

With this discovery, obesity specialists try to look for the main reason why a person gains weight and try different ways to lose them. They start with the least invasive treatment first before moving to another if it doesn't work. Dr. Kaplan said that he has 40 types of therapies and 15 types of drugs he can recommend to a patient.

As Dr. Caroline Apovian, director of the nutrition and weight management center at Boston Medical Center, said, it is still some sort of a trial and error thing.