John Tierney's Science blog has excellent commentary on junk nutrition....."Before we pass any more laws on what to eat, I wish we’d take a harder look at how often the supposed experts in nutrition have been wrong before... "

The science writer Gary Taubes in Good Calories, Bad Calories, writes that .... unlike science, nutritional hypotheses are not properly questioned and requestioned."

In science,

"Outstanding questions are identified or hypotheses proposed; experimental tests are than established to either answer the questions or refute the hypotheses, regardless of how obviously true they might appear to be. If assertions are made without the empirical evidence to defend them, they are vigorously rebuked. In science, as [the philosopher of science Robert] Merton noted, progress is only made by first establishing whether one’s predecessors have erred or “have stopped before tracking down the implications of their results or have passed over in their work what is there to be seen by the fresh eye of another.” Each new claim to knowledge, therefore, has to be picked apart and appraised. Its shortcomings have to be established unequivocally before we can know what questions remain to be asked, and so what answers to seek — what we know is really so and what we don’t. “This unending exchange of critical judgment,” Merton wrote, “of praise and punishment, is developed in science to a degree that makes the monitoring of children’s behavior by their parents seem little more than child’s play.”

But nutrition and obesity research don’t work this way. "The other problem with public health-related research is that the beliefs not only infect entire fields of science, but they spread beyond the science to the public, the politicians, etc., and so the number of those individuals invested in the erroneous belief grows exponentially and it becomes almost impossible to eradicate it or correct it."

"If public health research functioned like some of the harder sciences — high energy physics being the one I know best — then researchers would be ridiculed and perhaps even run out of the field for over-interpreting their evidence or publicly presenting the results of sloppy experiments or basing claims on premature evidence and none of this would have happened.

You can think of this kind of brutal response to bad science as an immune system that serves to protect reliable knowledge from infection by the infinite number of bogus but compelling ideas that are out there. The last place you want a science to find itself is where obesity research is today, with hypotheses of causation that can explain none of the pertinent observations, but yet are believed so fervently that no one can challenge them without being ostracized or declared a quack."

Tierny then asks "Is he right about the lack of an immune system in these fields of research? And if so, what can be done about it?"