Diet Books! How many do we need, really? I have to admit though, when I see a shiny new hardback in the local bookstore with an eye-catching image (a big stack of sinister-looking bagels, or a piece of broccoli in the shape of a brain) and an author with credentials – Dr. Mitch Somebody, M.D. – it’s hard not to get sucked in. Especially when you throw in the endorsements on the back cover by a host of other authors (who have all invariably written their own diet/nutrition books): “This book changed my life!” – Dr. Chad Betterman, M.D., author of N.Y. Times bestsellers, My Diet will Change your Life! and The Betterman Way. What’s kind of amusing is that we tend to automatically trust the opinion of doctors for advice on nutrition when in fact they receive, on average, less than 24 hours of nutrition-related training during med school, and only 2 hours in some cases. Having said that, there are of course several good nutrition books out there, some of which are written by M.D.s. The point I’ll hopefully get to later is that you need to be wary about what you read and vigilant enough to do a little fact-checking of your own.
So, I just finished reading a book called Proteinaholic, by Dr. Garth Davis, M.D., and it brought up a couple of interesting points. (By the way, he had Howard Jacobson, Ph.D., to help him read and interpret the 669 research papers and keep him on the straight and narrow – Jacobson has also researched science for two of T. Colin Campbell’s books and runs an interesting podcast called Plant Yourself). You can read my review of the book here – I’m only going to go into one aspect of it right now. But briefly, the main thesis of the book is that we are eating too much animal protein and this can lead to low life expectancy, heart disease, diabetes, obesity, and cancer. The fact that a diet rich in meat is not good for you shouldn’t come as a huge surprise at this point. It’s also well accepted by now that switching to a predominantly plant-based diet is one of the single biggest things (probably the single biggest thing) you can do to improve life on this planet. So, why is our protein consumption increasing?
Dr. Davis believes that we consume too much animal protein in part because we’ve received decades of conditioning from so many sources that protein is good for you – that in fact you can never get too much protein. When it comes to the other two “macronutrients”, fats and carbs, we’ve vacillated over their virtues and dangers for decades, opting eventually to split them into “good” and “bad” versions. But during all of these food fights, protein has maintained an untarnished halo around its little globular head. This reputation has been nurtured by decades of lobbying, advertising, and manipulation of the truth (aka deception and lies) by politicians, government agencies, industry boards, and special interest groups, all with vested interests in selling meat and dairy. There are several examples given in the book, including an account of Kansas Senator Bob Dole’s interesting reinterpretation of the recommendations of the 1977 U.S. Select Committee on Nutrition and Humans to eat less meat and dairy while consuming more fruits, vegetables, and grains. Apparently, following pressure from the National Livestock and Meat Board, Dole summarized the findings with a recommendation that we should to eat more lean meat (the “more” satisfying the Meat Board and the “lean” included as a nod to the Committee – hey, it’s not quite fruits, veggies, and grains, but how do you expect me to get reelected in Kansas if I’m touting a hippie rabbit food diet?)
I think that by now we are used to the fact that corporate associations and boards do their best to manipulate us. When evidence emerges that something they are selling is bad for us or harmful to the environment their wheels of public relations quickly kick into motion. However, over the last few years there has been a concerning trend that these manipulation tactics are creeping into the discipline of Science. In medicine, it’s well known that doctors take the Hippocratic Oath to do no harm, and although scientists take no oaths, it’s understood that their loyalty should always be to the Truth. But there have been several high-profile cases over the last decade of individual scientists falsifying data, and there has also been a lot of focus on failure to replicate work published by the pharmaceutical industry.
In Proteinaholic, Dr. Davis makes the point that if you are getting enough calories then you are getting enough protein. Any diet that consists of a reasonable mix of foods, even if 100% plant-based, will include enough protein. The question then becomes: is there a benefit from ingesting more than “enough” protein? In the U.S., the recommended daily allowance for protein is 56 grams per day for men and 46 grams for women (or around 0.8 g/kg body weight). The WHO/FAO recommendations are a little lower at 0.68 g /kg. Endurance athletes (who need more protein than bodybuilders) may benefit from a protein intake of 0.9 g/kg – that’s 67 grams for an endurance athlete who weighs 75 Kg. However, average protein intake (across a largely sedentary population in the U.S.) exceeds all of these levels, reaching around 109 grams per day in young adult males.
I wanted to double-check on our average protein intake and came across this paper that provided just the information I was looking for.
And that’s when things got weird. The paper looks innocuous at first – it simply charts data from a survey on protein intake in the U.S. But it’s really not a research paper at all – in fact it has virtually nothing to say – the entire paper appears to be a set up for the conclusion that:
Given the positive benefits of higher protein intake on satiety and other physiologic functions, efforts should be undertaken to help Americans consume the recommended amounts of protein.
This conclusion is reached without any references to back up the author’s vague claims on the “positive benefits of higher protein intake.” In fact there are only 11 references in the paper and none of them are references to research papers – the majority are just links to websites that describe the USDA food pyramid. So, basically, the paper lists data on protein intake and, even though this data shows that intake levels are above both the WHO and U.S. RDA values, the author goes on to conclude that we should really increase our protein intake.
So, the paper is really a thinly disguised advertisement for consuming protein, masquerading a science paper. The sole author is not associated with a university – he’s basically running a one-man-show consulting firm called Nutrition Impact.
Nutrition Impact is a small consulting firm that specializes in helping food & beverage companies develop and communicate aggressive, science-based claims about their products and services.
His funding source for the paper:
An honorarium for preparing the manuscript and reimbursements of travel expenses for attending the Protein Summit were provided to VF by the Protein Summit sponsors. VF has also received research grants from The Beef Checkoff through the National Cattlemen’s Beef Association.
The Journal that published the paper? It’s not, as you might expect, a virtually unheard of trashy journal – The American Journal of Clinical Nutrition has an impact factor of 6.8 (quite high) and claims to be the most frequently cited journal in nutrition and dietetics.
Marion Nestle and others have been pointing out for several years that many of the journal’s board members are heavily associated with the food industry and their conferences are looking more and more like advertising sessions than scientific meetings.
So perhaps it’s a sign of the times that Dr. Davis felt the need to devote an entire chapter of Proteinaholic (Research Truth and BS: How to Speak Science) to guiding readers on interpreting scientific papers so that they can develop an instinct for when they are being manipulated. The way things look right now, the problem seems to run deeper than a few isolated papers – an entire Journal appears to have been compromised.
I think we have to fall back on the advice offered by Jon Stewart in his final episode of the Daily Show.