I watched a documentary on BBC called 'The Men Who Made Us Thin', and it was actually very interesting in shedding light on how the diet industry came about. Also, it actually proved that all of these 'magical' diets are a huge waste of time and in fact most people always end up failing them.
The first thing the show highlighted was that near enough everyone is obsessed with their weight and what they are eating, and in fact people who aren't over weight are counting calories daily. So, there is no wonder why the diet industry is so huge when so many people are obsessed with their weight and body image. This may of came about because in 1959 'Met Life' published new desirable weights taking into account peoples BMI, influencing those who were not overweight to start losing weight, initiating unrealistic body and weight ideals.
Anyhow, the show identified that some of these diets are actually ridiculous and it amazes me how much success they have had and how many people actually are convinced by them. I mean one was called 'Six Weeks To Omg' which suggests blowing up a balloon everyday can tighten your stomach. Furthermore, the books slogan is to be 'skinnier than your friends' turning weight loss into a competition, portraying that these amazing diets are nothing but a business ploy, and honestly do not have peoples health at interest.
The reason why you shouldn't diet is because diets do not work. If these diets did work than why is over 50% of the population still obese and why is there still a huge consumer market for dietary products? Dieting does not work because your body goes into starvation mode and eventually you will regain the weight completely, they are not a long term solution.
Ancel Keys conducted an experiment between 1944-45 called the 'Minnesota Starvation Experiment' by which they wanted to test the effects of starvation on the body physically and psychologically by reducing participants calories to about 1500 a day. The experiment concluded that starvation can result in a decrease in the metabolic rate and in fact in the long run the participants gained more weight than they were prior to the experiment. Thus, indicating that dieting is clearly not an effective nor healthy solution to losing weight. Additionally to this, the effects of starvation psychologically resulted in an increase in depression and isolation, one participant became so affected mentally that he chopped of three of his fingers.
So why is it that although these fad diets do not work yet, people still go back to them? The show illustrated that less than 20% can sustain their goal weight after being on 'Weight Watchers' a multimillionaire company, but people are continuing to retry these diet plans. I think the answer like any consumer company, the dieting companies are a business and thus create something short term because they know that people will come back to it. This is because consumers, previously had short term weight loss results, which is enough to encourage them to retry the same diet. Honestly though if these diet plans really did work than why is over half the population overweight? Simple, they do not work.
To conclude it is clear that dieting is a waste of time, if you want to lose weight then be smart, eat healthily and exercise.
I obtained most of my information from here