With regard to Dieting and Weight Issues, it is becoming clearly evident  that the members of the Medical Profession, including those who are part of the Scientific Community, are greatly in need of a REALITY CHECK.  A Reality Check is something which shows you that the real situation is different from what you believed or hoped. 

What is considered as "conventional wisdom" is that :

Most people burn X number of calories, and if they reduce that X number by 500 calories per day, in one week they will lose one fat pound (3500 calories = 1 fat pound). 

Therefore after doing this for 10 weeks, they will lose 10 pounds. Because they are now 10 pounds lighter, they will burn slightly less than the X number of calories their body needed before their weight-loss, and they can then easily eat that new X calorie number and maintain that weight loss.

This process can be continued indefinitely, and by following through, it will result in the body's loss of all "excess weight", and thereafter, will result in the body's maintenance of that "ideal weight" .  As a result of this people will become Thin and Healthy. 

At the bottom of this article, I give more detail about this numbers issue, but the POINT IS that while following this Basic Process gives short-term weight loss results, only a very few people ever achieve long-term weight loss results.  

Certainly, the REAL SITUATION Here is DIFFERENT from what the Medical Profession, the Scientific Community, and the General Public, BELIEVES or HOPES it to be.

DietHo...

Research studies on the subject of misinformation show that:  

When information doesn’t square with someone’s prior beliefs,

Not all false information goes on to become a false belief -- meaning: a lasting state of incorrect knowledge -- and not all false beliefs are difficult to correct.

For example astronomy. If you were asked to explain the relationship between the Earth and the Sun, you might do so incorrectly, and a friend who understands astronomy might correct you. No big deal, you simply change your belief.

But in the time of Galileo, the view of the Earth-sun relationship was tied closely to ideas of the nature of the world, the self, and religion. If Galileo tried to correct your belief, the process wouldn't be as simple.

The crucial difference between then and now, is the IMPORTANCE of the Misperception.
 When there's no immediate threat to our understanding of the world, we change our beliefs. Problems occur when that change contradicts something we hold as important.

False beliefs stem from issues closely tied to our conception of self. False beliefs, it turns out have a great deal to do with self-identity; What kind of person am I, and what kind of person do I want to be? This self-identity issue affects all ideologies.

Facts and evidence simply aren't that effective, given how selectively they are processed and interpreted.   Strongly held beliefs continue to influence judgment, despite correction attempts … even with a supposedly conscious awareness of what is happening.

When someone believes something strongly,  new information isn't going to change their mind.  
 

I am now I'm now in my 9th year of maintaining a "normal" weight after a large weight-loss.

Accomplishing this has been incredibly hard, and, even after all these years, this task is not getting any easier for me.
See: Running DOWN the UP Escalator.

The Truth about weight-loss and maintaining weight-loss isn't something that we're EVER going to hear from Marketing Interests … (which includes most doctors and nutritionists) … however, Facing it, Understanding it, and Accepting it, can be very helpful.

Below is a recent CBS news article discussing this issue.

Obesity research confirms long-term weight-loss almost impossible. 
                          by Kelly Crowe, CBS news 6-4-14

There's a disturbing truth that is emerging from the science of obesity. After years of study, it's becoming apparent that it's nearly impossible to permanently lose weight.

As incredible as it sounds, that's what the evidence is showing. For psychologist Traci Mann, who has spent 20 years running an eating lab at the University of Minnesota, the evidence is clear. "It couldn't be easier to see," she says. "Long-term weight loss happens to only the smallest minority of people."

We all think we know someone in that rare group. They become the legends — the friend of a friend, the brother-in-law, the neighbor — the ones who really did it.

But if we check back after five or 10 years, there's a good chance they will have put the weight back on. Only about five per cent of people who try to lose weight ultimately succeed, according to the research. Those people are the outliers, but we cling to their stories as proof that losing weight is possible.

"Those kinds of stories really keep the myth alive," says University of Alberta professor Tim Caulfield, who researches and writes about health misconceptions. "You have this confirmation bias going on where people point to these very specific examples as if it's proof. But in fact those are really exceptions."

Our biology taunts us, by making short-term weight loss fairly easy. But the weight creeps back, usually after about a year, and it keeps coming back until the original weight is regained or worse.