Dr. Aseem Malhotra, lead cardiologist of the UK's National Obesity Forum recently told the Daily Mail that he doesn't go near margarine-type products that claim to lower cholesterol and he advises his patients to stay clear of them as well.  Dr. Malhotra (no friend to food freedom for his desire to see regulations placed on the food of which he disapproves) said of these products:

First, they are expensive; second, these products are artificial, packed with unnatural products that really can’t do you any good; and third, I don’t believe there is any demonstrable health benefit.

They may have a very marginal effect on cholesterol, but — and this is critical — this hasn’t been established as having any clinical benefit in reducing the risk of a heart attack. In short, the whole saturated fat argument has been ridiculously overhyped.

A review of studies in the American Journal of Clinical Nutrition in 2010, which analysed almost 350,000 people for up to 23 years, revealed no consistent evidence linking saturated fat and cardiovascular disease.

So, what does Dr. Malhotra advise his patients to eat? Butter! That's right, the famous heart doctor and respected advisor to governments tells his patients to do what generations were doing — eating butter! — until government advisory panels started freaking out about everyone's butter consumption which led the medical community to tell people to switch to margarine.

The lesson here is clear: Health advice shifts. There is consensus; and then there is not. There are popular trends in the medical field and, very often, those trends go out of fashion. Doctors, like Vogue editors, dole out the fashionable advice popular at the time.

Why is this important?  Because this year, the U.S. Department of Agriculture along with other federal agencies will begin the process of updating the government's dietary guidlines (the final guidlines won't be issued until 2015, but the process will begin next year).  As in previous years, agency experts and select medical professionals will dole out advice that in a few years they will throw out as dated, or just plain wrong; like the eat margarine not butter advice doled out a few years ago.  Oops, sorry dieters. We were wrong, again.

As I wrote soon after the Dietary Guidlines were released in 2010, maybe it's time for the government to get out of the weight loss industry. Do we really need government agencies doling out dieting advice when there's a booming, billion dollar private industry already doing it?  Consider the ubiquitous television shows on weight loss and nutrition. The endless number of finger-pointing talk show hosts either on a diet or talking about which diet is the best. The books, magazines and smart phone apps dedicated to weight loss. Just glance at the shelves in your local grocery store to see how much real estate is dedicated to diet foods. Diet advice is being drilled into the American psyche with no help from the government.

But perhaps more importantly, Americans simply aren't looking at the dietary guidlines. Want proof?  Just consider what USDA Secretary Tom Vilsack said when the 2010 Dietary Guidlines were released: "I must admit personally that I never read the dietary guidelines until I got this job."

So, in other words, Secretary Vilsack had to be paid to read the USDA dietary guidelines.