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Saturday, August 2, 2014

School lunches: Measure twice - cut once

“History doesn’t repeat itself, but it does rhyme” Mark Twain

Maureen Ogle, in her book “In meat we trust”, reminds us that school lunches have always been on the menu of food controversies. In 1926, the New York School Board banned frankfurters from school lunches. She writes that: “The board’s lunch director explained that the food was unsuited to students’ nutritional needs” The director went on to say that: “The sausage was so heavy that when children ate it, they neglected to eat green stuff and milk”. And you’ve guessed it – no data were gathered upon which to construct evidence based policy. The director simply looked into his or her heart in search of wisdom. The issue of school lunches lingers on and whilst I want to end on a positive note, I will cite three studies which all show that poorly informed or misinformed interventions in food choice to improve nutritional balance in school lunches can back fire.

Case 1. A group from Tufts University examined the effect of three years of intervention in the US National School Lunch Programme to reduce total fat and saturated fat intake[1]. They observed that as the % of calories in lunches decreased, the % of calories from fat increased. This is known as the sugar-fat seesaw. Basically, if one reduces the level of fat in a child’s energy supply, children will compensate for the loss of fat by eating higher amounts of other foods and time after time, it has been shown that as you lower fat, you raise sugar. So, in today’s terms where sugar is popularly perceived to be utterly toxic, would one describe the reduction in total fat and saturated fat intakes as a success or would the increase in % energy from sugars be seen as a failure. This writer would deem it a success as fats and especially saturates are directly implicated in elevated plasma cholesterol on the basis of dozens of randomised controlled feeing studies while almost none exist for sugar at the normal or even slightly normal levels of intake.

Case 2. Fruit and vegetable intake are common targets in school lunch programmes and the general belief is that because they have a low energy density (fewer calories per unit weight) that higher intakes will reduce energy intake. Researchers from the University of Wiscanson-Maddison studied food choice in school canteens using digital imaging to identify foods selected and portion size[2]. They studied schools taking part in the Farm to School project. They found that whereas fruit and vegetable intake increased, the intake of other foods decreased such that energy intake remained constant. Thus if the objective was to reduce energy intake, the project failed. But a higher intake of low-salt, low fat fruit and vegetables would reduce overall the negative targets of foods (fats, saturates etc.) and thus the project should be deemed a success.

Case 3: Brian Wansink and his colleagues at Cornell University, reported on a pilot study evaluating the consequences of banning chocolate milk in school cafeterias[3]. Chocolate flavoured milk represents about two thirds of all mile in the US school cafeteria system. In 11 Oregon schools, chocolate flavoured milk was banned from the lunch menu and the group from Cornell used data gathered in the National School Lunch Program to assess the success or otherwise. Total milk sales fell by 10%. White milk increased but some 29% of this non-flavoured milk was wasted, that is unfinished by the students. In all, the numbers of children using the School Lunch Program fell by 7%. Success or failure? Once again I would say the outcome could have been predicted if someone had invested funds in attitudinal research, which would have saved a lot of money and effort. My father, a carpenter, always used the phrase: “Measure twice – cut once”. In effect, these school lunch managers, in all three cases never measured even once. But they were all mad keen to cut!

Which brings us to a major recent study from the University of Chicago, which carried out a survey of 557 representative schools to assess the impact of the updated standards of the National School Lunch Program[4]. The ratio of “agree”/ “agree strongly” to “disagree”/ “disagree strongly” that “students generally seem to like the new school lunch” was about 70:30. This contrasts with the opinion: “At first, students complained about the new lunch” where 57% agreed or agreed strongly. So, slowly the students absorbed the newer healthier lunches. About 2/3 students have fewer complaints about the new lunches and the same number doesn’t seem concerned about the changes. One main area of complaint was the withdrawal of pizzas from some school menus. Students were happy with healthier pizzas but not happy with the absence of any pizza option. So this is a positive note for innovation school lunches. However, the more that innovation is built on a priori data, the more likely it is to be successful and, regrettably, the general trend is to cut and not measure in advance.

Here in the EU, where national policies on school lunches differ according to member state, the Commission has published a very useful overview of existing practices and has set the scene for future joint action to help improve the nutritional quality of school lunches[5].

One area of public health nutrition that is badly missing is the measure of the impact of school lunches on the student’s overall daily dietary performance. In other words, for how many children does the school lunch counter balance poor dietary practices at home and outside the home and school environments? For how many pupils is the home driving most the student’s daily intake of nutrients to optimal. Such data are very important to understand the true social impact of school lunches.

[1] Dwyer JT et al (2003) Journal of Adolescent Health, 32, 428435
[2] Bontrager Yode AB et al (2014) Childhood Obesity July 2, e-pub ahead of print
[3] Hanks AS et al (2014) PLOS ONE, 9, (4), e91022
[4] Turner L and Chaloupka FJ (2014) Childhood obesity, 10, number 4

Sunday, July 27, 2014

Celebrating 100,000 views of Gibneyonfood

“The media is today awash with articles on all aspects of food and health and some are so non-sensical that I thought I'd start my own blog to provide an alternative medium through which an informed view on food and health can be delivered. The blog will be a weekly event coming live every Monday morning, beginning on Monday November the 8th and will cover a wide range of topics”.

So began my first blog on November the 1st, 2011.  Now, 80 posts later, the blog has passed 100,000 page views giving an average of 1,251 views per post and an average of over 3,000 views per month. At first I welcomed comments on individual blogs but stopped that facility when people abused it to advertise their health food rubbish. A typical comment might be: “What a fantastic blog and all antioxidants are not the same. Try[1] for best results”. Another reason to block comments was the advent of porn tags. One day you’d look at the Google Analytics and see an enormous rise in views from some quite unlikely country. When I sought out the most popular referral site, I hit an XXX site. The advice from  Google was to let it pass and never open a referral site you don’t know about. My own book “ Something to chew on ~ challenging controversies in food and health” was the most viewed which is great. I’m currently working on another with the tentative title: “Ever seen a fat fox - the science of human obesity”. After that the rankings are as follows: “Oh Sugar! Wrong about fructose”, “Dolly Parton and the art of dieting”, “Sugar taxes and weight loss prediction”, “Michael Pollan’s in defense of food – a critical appraisal”, “Dietary advice with a grain of salt, “Dietary supplements: useless or useful”, “Sex, obesity and the seven deadly sins”, “Fructose – challenging the myths” and “Sorry Dr Lustig: A calorie is still a calorie”.

 As regards countries,, averaging the last 33 months the country top-ten rankings for views are: US, Ireland, UK, Spain, France, Germany, Romania, Canada, China, Australia.  However, that varies by time. For example taking today (defined by Google analytics as the most recent 24 hours), the rankings now include the Ukraine (life goes on there), Sweden and Russia. Many EU states, Gulf States. Middle East and South American countries also view the site but their contribution is outside the top 10. I have very few views from sub-Saharan Africa so if any readers want to pass on the URL to colleagues in SSA, I’d be very grateful.

I’ve enjoyed blogging and ranting and iconoclasting and I hope you continue to enjoy the product. Thanks for taking a look. Next blog will be on school lunches.

[1] At the time of writing, no URL exists for ,which is entirely fictitious! 

Tuesday, July 22, 2014

Super-foods, super-diets and pseudo science

From time to time, certain  “super-foods” and “super-diets” emerge to dominate the menus of fashionable restaurants and chique delicatessens. The most recent super-food has been quinoa (pronounced KEEN-wah). Apparently, it will treat hypertension, diabetes is a natural appetite suppressor and is anti ageing[1]. In fact, the UN Food and Agricultural Organization deemed 2013 to be “The Year of Quinoa”[2]. The Director General of FAO stated that “…quinoa can play an important role in eradicating hunger, malnutrition and poverty”. The facts are however somewhat at variance with this view of quinoa as a super-food. Firstly, it is stated that its protein quality is unique in the plant world in that it is complete in all the 8 essential amino acids. This leaves the non-expert think that some plant foods therefore lack one or more essential amino acids. Not so. All plant proteins contain all amino acids but they vary in the relative amount of each. To rank the quality of a protein, its “protein digestibility corrected amino acid” (PDCAA) score is calculated. Three proteins gain a perfect score of 1.0: two of animal source, egg and whey protein and one of plant origin, soy protein. According to an entry in Wikipedia (most Internet listings for quinoa are from advocacy groups), quinoa, along with amaranth, buckwheat, hempseed, and spirulina fall below 1.0 but they are still called complete proteins because they contain sufficient of all the nine essential amino acids to meet the dietary needs of man[3]. So, quinoa is hardly unique despite its hype. If we turn to protein levels, we find that the following are the levels of protein in average servings of some plant food: amaranth, 3.8; rice, 4.0; beans, 15.0; lentils, 18.0 and soybeans 29.0[4]. Again, this hardly qualifies quinoa as a super-food. Quinoa is putatively “packed” with dietary fibre. An average serving of quinoa has the same amount of fibre as amaranth (5g) which does not compare well with other plant foods: lentils with 16g per serving and both beans and soybeans with 30g. Quinoa is also a truly marvelous source of antioxidants but most of these are simply natural bioactives and not nutrients and there is no serious data linking such plant bioactives to the incidence of chronic disease or risk factors for chronic disease. The hype on quinoa has caught the interest of researchers. Thus in the 20 year period from 1991 to 2011, PubMed lists 20 studies published on quinoa. In the last 2.5 years, a further 20 were added to the literature. According to the Wall Street Journal, there was a 9-fold increase in quinoa imports to the US between 2000 and 2007 and the price per pound almost doubled. This is all good news for the Andean farmers who grow it but not for the Andean people who rely on this crop as a staple food. Quinoa is more likely to grace the shelves of niche food stores in Manhattan to feed the worried well than it is to feed the billion people who go to bed hungry every night.
Besides super-foods we have super-diets and to illustrate the nonsense of super-diets, I will draw heavily on the writings of Harvey Levenstein in his book: “Fear of Food[5]” and specifically the chapter on “Natural Foods in Shangri-La”.
Sir Robert McCarrison (1878-1960), a medical doctor with the British Army in India, toured a remote valley at the foot of the Himalayas, now in Kashmir, Pakistan, which was the home of the Hunza people, the Hunzakut. He attributed their longevity and their physical and sexual fitness to their diet of unprocessed natural foods of milk, eggs, grain, fruit and vegetables. In the late 1940’s a former employee of the US Inland Revenue Service, wrote a book on the Hunzakut, never having visited the region. His book began to attract some attention and by 1957, the New York Times chief foreign correspondent visited the Hunza valley and confirmed that indeed the inhabitants lived to a very old age on a diet of dried apricots and powdered milk. Films were made featuring the Hunzakut and more books were written on their great health, physique, longevity and sexual prowess which persisted well into their 90s. In 1959, President Eisenhower’s cardiologist had an air-force doctor fly to the Hunza valley to check out there cardiac function and sure enough, a perfect bill of health came back. He added: “ A man in really good shape can eat up to 3,000 apricots in one sitting”! If it takes say 20 seconds to eat an apricot, then an apricot feast would last over 16 hours!!! The Hunza fever in the US reached the dizzy heights of an editorial in the Journal of the American Medical Association[6]. Then in 1956, a US geologist set up a small clinic in the Hunza Valley and was instantly inundated with cases of malaria, dysentery, parasitic infestations and symptoms of vitamin deficiency. He noted that in Spring, the entire valley ran out of food and starved until the barley harvest arrived. The Mir who ruled the valley, owned 25% of the land and of course was well fed as were his lackeys. He did visit the clinic to be treated for dyspepsia, requiring an ant-acid for relief. Subsequent visits by British, Japanese and French physicians confirmed widespread deficiency diseases such as goiter, a deficiency of iodine. Malnutrition was found to be rampant. Hunzamania is still rampant. You can buy on Amazon “Crystal Energy Hunza Water” and if you buy 2 you get 1 free[7]. How much? US $99.99!!

The fashion for super-foods and super-diets isn’t new and we will see quinoa slip in favour of the next fad. Its mainly pseudo-science.

[5] Fear of Food is published by Chicago University Press (2012)
[6] JAMA (1961) February25th. “Longevity in Hunza land”