A great deal of science today is Junk Science. This is how the U.S. Department of Justice described it in 1985:
"The use of such invalid scientific evidence (commonly referred to as
'junk science') has resulted in findings of causation which simply
cannot be justified or understood from the standpoint of the current
state of credible scientific or medical knowledge."
More contemporary definitions exist, but I don't think any describe the phenomenon better than the above.
Frequently poorly designed research projects, funded by some body that has a vested interest in the results are twisted and thwarted to produce the desired results. If they don't do that they often don't see the light of day. Those results are often extrapolated to huge segments of the population to generate vast sums of money as in the 'gluten free' industry. Only a tiny percentage of the population are gluten sensitive, but a very significant proportion think they are and generate vast sums for the purveyors of gluten free foods.
Junk science is pushed by the likes of Dr, Oz, whom the American Medical Association has never had the courage to take to task. Many of the same ilk with no appropriate training or knowledge,present themselves as experts pushing junk science and spreading misinformation. Even some highly trained physicians, in their efforts to simplify, oversimplify and do not present a very coherent explanation.
Then, the Hollywood experts from DiCaprio to Clooney, most of whom do not even understand the basis of the junk science, take authoritarian positions and their word is taken as Gospel. DiCaprio was in Calgary this past winter when a Chinook brought the temperature from well below 0 degr C upinto the high teens. I heard DiCaprio in an interview state he has seen global warming in Calgary and everyone said they had never heard of such warming before. I guess he only spoke to his Hollywood pals. He couldn't have spoken to an Albertan.
Politicians and their janissaries, love all this,of course. They can often manipulate the data to justify their incompetence and to impose new taxes to benefit humanity.
There is probably no area in which junk science has had more influence than obesity. When I walk into my local bookstore, there are shelves of books on the 'only diet' that really works. Here are a few of the titles: Atkins Diet, Best Life Diet, Blood Type Diet, Glycemic Index Diet, Macrobiotic Diet, Mediterranean Diet, Grape Fruit Diet, Beverley Hills Diet, South Beach Diet, etc.,etc..
Now, you know that if any one of these diets was really effective it would very quickly replace the others. They continue to proliferate.
Having treated overweight and obese patients for many years I have found that success was much more dependent on the motivation and persistence of the patient and their ability to make and maintain life style changes, than on any particular type of diet. In other words, behaviour modification is an essential ingredient: there is no silver bullet, there is no magic potion. The immutable equation holds. More calories consumed than burned results in obesity.