We have at least 30 years of research on the effects weight loss interventions. What stands out to anyone who has even a rudimentary grasp of the literature is the unprecedented consistency of the outcomes. Every weight loss initiative that has been studied, regardless of the population involved, the length and intensity of the program, the type of exercise and/or food intervention, the credentials of the people running the program, and every other variable imaginable has come up with the same set of results:

• Many people lose weight during the program
• When the program is over, people begin to gain their weight back
• Within a year or two most people have gained most of their weight back
• Some people end up weighing more than when they started the program

Because they have not changed their habits permanently?

Don’t be misled by the rhetoric coming from vendors and consultants. If all weight loss programs in the last 30 years have resulted in the same outcomes, there must be a reason. Here are 5 questions you can ask to help protect you from the dangers:

1. What are the qualifications of the people promoting these programs?
2. How is this program different from all those hundreds of others?
3. What is the dropout rate?
4. What is the weight trajectory for those who lost weight in the first 6 months  to one year after the program is over?
5. What percentage of the people who finish the program keeps their weight off 1, 2 and 3 years after the program is over? (Keep in mind that the evaluation must include dropouts as well.) 

I suspect those "programs" are not suitable for a real (or realistic) real-life scenarios.  For instance, in Biggest Loser the participants were exercising so many hours per day that no full-time job would fit in. Or food choices/preparations were unrealistic.  So yes, essentially the problem with those programs that they "end", and even if a person does make some adjustments to their life, the weight loss is not permanent.

It is a question of how much of YOUR quality of life can you sacrifice to be thin. It is possible to not be thin, and be healthy - and beautiful, and attractive.

Right! The goal is to be healthy. Not necessarily thin.