Currently browsing posts about: Diets

I cannot understand the revisionist attack on the work of Ancel Keys, who died at the age of 100 in 2004.  Most scientists are lucky to have made important contributions in one area.  Keys produced outstanding work in several:

• High altitude physiology
• The physiology of starvation (for this alone, he should be honored)
• Mediterranean diet benefits
• Heart disease epidemiology

The fuss, of course, is over this last one, particularly his role in the Seven Countries Study.  The arguments falls right into today’s absurd debate about sugar vs. fat as a cause of disease (absurd, because we don’t eat sugar or fat; we eat foods and diets that provide energy measured as calories).

What started off this most recent fuss is Ian Leslie’s The Sugar Conspiracy, which begins with the question “How did the world’s top nutrition scientists get it so wrong for so long?”  This alone is a red flag.  “Everything you thought you knew about nutrition is wrong” is a sure signal for caution; that’s not how science works.

The attack on Keys’ work induced the True Health Initiative to develop a ​White Paper in defense (here’s its press release).  Its authors: Katherine Pett (who had written a blog post in defense), Joel Kahn (who also wrote a blog post) Walter Willet (long a champion of Mediterranean diets), and David Katz (who wrote about it in his own blog post).

In response, Michael Joyner pointed out that R.A. Stallones (a professor of mine at the School of Public Health at Berkeley) had made the same arguments years ago.

Another defense of Keys’ work comes from Kevin Klatt, a nutrition biochemistry PhD student at Cornell.

Sarah Tracy, a science historian at the University of Oklahoma, has been working on a biography of Ancel Keys for years.  I can’t wait for it to come out.  We need to have Keys’ life and work put in reasonable perspective.

While waiting for the fat v. sugar debate to resolve (I’m predicting it won’t), eat a healthy diet, enjoy what you eat, and be skeptical when writers write about nutrients, not food.

Here’s another one of this site’s roundup of articles on specific topics, written from the perspective of food companies.  Paleo sells.

Special Edition: Paleo: Fad, Trend, or Movement?

Definitions vary, but most advocates of the Paleo diet think the dietary rot set in once humans stopped hunting and gathering and started to grow crops and raise animals for food. So grains, legumes, and dairy are typically off limits (although some Paleo fans say grass-fed dairy is OK). While critics say any diet that eliminates major food groups should be treated with caution, the number of products featuring Paleo claims and certifications is growing rapidly, and many retailers and manufacturers are now looking at how to tap into the trend, which some market researchers see as the next evolution of low carb, and gluten-free.

• Natural channel still accounts for bulk of Paleo product sales, but sales in conventional channels are growing faster, says SPINS: Where are Paleo-positioned products thriving? SPINS data break it down by channel and category… Read
• Low-carb, gluten-free and now Paleo… Another anti-grain fad or a true concern for bakers?: Bakers shouldn’t worry too much about Paleo, but the trend does call for increased grain education and better industry innovation, warn grain advocacy groups… Read
• Whole30 certification helps brands boost exposure, sales and shelf space: Certifying a product as approved by the popular Whole30 diet is a “pretty intensive” process, according to the diet’s co-creator, but for the few and proud that make the cut, the licensing deal can provide exposure to a fiercely loyal consumer base, boost sales significantly and help secure shelf space in competitive categories… Read
• PALEO IN FOCUS: Are we ‘supposed’ to drink cow’s milk? It’s the wrong question, says professor: ‘Paleo’ fans argue that the dietary rot set in when we stopped hunting and gathering and started producing foods (dairy, grains, legumes) our bodies are not adapted to digest. But does the theory behind this approach hold water?.. Read
• Passionate paleo followers can fuel brand awareness, sales for compliant packaged products: Between 1 to 3 million people in the United States follow the paleo diet, and yet relatively few packaged products comply with the regime – making it a market brimming with potential that once tapped could quickly drive brand awareness and sales, according to the co-founders of frozen dessert brand Snow Monkey… Watch now
• What’s the size of the Paleo foods prize? Mintel and IRI weigh in: Paleo themed product sales could soar to $4bn in the US in the next three years if enough manufacturers invest, according to IRI, although Mintel says we’re not looking at the next Greek yogurt… Read
• Paleo certification requests have doubled annually, scheme embraced by ‘household names,’ says Paleo Foundation: Demand for Paleo-certified products are on the rise. But is the diet – and the certification scheme – based on sound science? We chat with Paleo’s critics and proponents to get the inside scoop… Read
• Our Paleo ancestors were more active than us, but did they really have an optimal diet?: Supporters of the ‘Paleo’ diet (a hunter/gatherer-style approach to eating) urge us to eschew grains, dairy and legumes – among other things. But any diet that eliminates major food groups should be treated with caution, argue two high-profile dietitians we quizzed as part of our weight management special edition… Read
• Meteoric sales growth at Primal Kitchen: ‘Things just exploded as soon as we launched’: “We did everything you’re not supposed to do,” observes the COO of Primal Kitchen, which exploded out of the blocks with a sugar-free avocado oil-based mayo in February 2015, notched up revenues of $13.2m in 2016, and is expecting to almost double that in 2017. ..

The much delayed UK government’s plan for dealing with childhood obesity has finally been released to virtually universal dismay over the missed opportunity.

The strategy is now a Plan, and says it is “the start of a conversation.” It reconfirms the government’s intentions to implement a soft drink tax, subject to consultation, but does not include a range of measures recommended by its own Public Health England and by last year’s House of Commons Health Committee, such as reduce food marketing and controls on retail promotions. It relies on voluntary sugar reduction by the food industry and encouraging parents to help increase children’s physical activity to meet the recommended 1 hour per day.

It’s fun to read the criticisms: nobody minces words.

An editorial in The Lancet

The UK Government’s long-anticipated response to the childhood obesity crisis disappointed everyone. From doctors, health charities, and celebrities to the very industry it seeks to propitiate, the Childhood Obesity Plan, published with as little noise as possible in the summer recess, has met with resounding criticism. As a Comment in today’s Lancet highlights, the strategy has been delayed for a year, and in that time it has been watered down to a vague Plan with no teeth.  Reading the report from start to finish gives the impression that its authors haven’t.

The Lancet editorial continues

The absence of curbs on industry practices that contribute to childhood obesity—promotions of unhealthy food in supermarkets and restaurants; advertising of junk food through family TV programmes and social media—seems like a gift to industry.

The Lancet is especially miffed because it ran a series on obesity last year that made it clear what kinds of policies needed to be enacted.

Also in The Lancet, World Obesity’s Tim Lobstein and Klim McPherson say

What we read in the government’s Plan is nothing particularly new, nothing bold, and very little that can actually be measured to assess the Plan’s success. It is a document that is not only a disappointment to public health professionals, but also evidence of a government walking away from its moral duty to protect the health of children, and its fiscal duty to protect the NHS from the consequent costs.

The Association for the Study of Obesity (ASO) issued a statement:

the plan is a lost opportunity to provide leadership and commitment in tackling childhood obesity as part of a whole systems approach. It lacks bold actions that are needed to reverse the current high levels of child obesity such as: a ban on junk food advertising before the 9pm watershed; reduction in portion sizes; reformulation targets for industry that address high energy density foods; curbing the promotion of unhealthy foods in supermarket; investment to increase and extend evidence-based child weight management services. All of these would be robust, evidence-based actions and would start to tackle the root causes of obesity in this country.

Again in The Lancet, Yoni Freedhoff and Kevin Hall point out the need for more sensible weight loss studies:

Over the past several decades, dozens of randomised controlled trials have compared various diets for the treatment of obesity. Ideally, such studies should have provided strong evidence for clear clinical recommendations and also put a stop to society’s endless parade of fad diets. Unfortunately, the evidence base remains contested and the “diet wars” continue unabated…What is especially striking is the similarity of the long-term pattern of mean bodyweight change, irrespective of diet prescription.⁵ …Fewer resources should be invested in studying whether or not a low-carbohydrate diet is marginally better than a low-fat diet, or whether intermittent fasting provides marginally better short-term outcomes than a so-called Paleo diet.

Their study provides further evidence why we need stronger policies for preventing obesity.  It’s too bad the UK couldn’t do better.

And if you think things are any better in New Zealand…

The food industry has hit out at claims in a leading journal that New Zealand’s childhood obesity plan was flawed and that the government valued corporate profit over public good. The Food and Grocery Council said that an editorial in the New Zealand Medical Journal, which claimed that the government’s strategy did not address excess sugar intake, was “flawed on many fronts.  Moreover, the FGC complained that its response to the article, solicited by Fairfax Media, was not run.

Addition, September 14

• Jamie Oliver weighs in—The Guardian

I breathed a long sigh when I read Gina Kolata’s We’re So Confused: The Problems With Food and Exercise Studies in the New York Times on August 11.

Nearly everything you have been told about the food you eat and the exercise you do and their effects on your health should be met with a raised eyebrow… The problem is one of signal to noise. You can’t discern the signal — a lower risk of dementia, or a longer life, or less obesity, or less cancer — because the noise, the enormous uncertainty in the measurement of such things as how much you exercise or what exactly you eat, is overwhelming. The signal is often weak, meaning if there is an effect of lifestyle it is minuscule, nothing like the link between smoking and lung cancer, for example.

This is a pessimist’s view.  I, however, am an optimist.

Nutrition advice could not be easier to understand.  Eat plenty of vegetables and fruits; balance calories; don’t eat too much junk food.

David Katz must agree.  He asks: Diets, Doubts, and Doughnuts: Are We TRULY Clueless?

No, we are not, absolutely not, emphatically NOT clueless about the basic care and feeding of Homo sapiens…In the New York Times this past week, Gina Kolata made the case that almost all studies about diet, exercise, and health are suspect in one way or another, and that therefore we are confused about lifestyle practices for health, and justifiably so. The first point is valid; the second is utter nonsense…A global consensus of expert judgment concurs… Routine physical activity and a diet of mostly minimally processed vegetables, fruits, whole grains, beans, lentils, nuts, seeds and water when thirsty redounds consistently to the advantage of human health. It offers benefits to the planet as well.

Or, as Michael Pollan famously put it:

Eat food, not too much, mostly plants.

Articles like that one add to the confusion; they don’t help clear it up.

Yesterday I explained why “butter is back” is not useful dietary advice, even when studies show that eating butter has little or no effect on disease risk (the total diet and calories are what matter).  Now I can say the same thing about low-carbohydrate diets.

The debate about whether fat or carbohydrate is responsible for obesity has passionate advocates on both sides, although those for carbohydrates predominate in the press these days.

As explained by Julia Belluz of Vox,

The main scientific model behind the low-carb approach is the “carbohydrate-insulin hypothesis,” which journalist Gary Taubes, Harvard professor David Ludwig, and others have extensively promoted. It suggests that a diet heavy in carbohydrates (especially refined grains and sugars) leads to weight gain because of a specific mechanism: Carbs drive up insulin in the body, causing the body to hold on to fat and suppress calorie burn.

According to this hypothesis, to lose weight you reduce the amount of carb calories you eat and replace them with fat calories. This is supposed to drive down insulin levels, boost calorie burn, and help fat melt away…instead of just cutting calories, you’re supposed to change the kinds of calories in your diet to lose weight.

To his great credit, Gary Taubes was willing to put this hypothesis to the test.  He organized the Nutrition Science Initiative (NuSI) to fund studies that he must have hoped would demonstrate the benefits of low-carb diets.

To its great credit, NuSI recruited highly experienced and respected obesity investigators to design and conduct the studies.

The first of these studies has just been published.   It fully discloses the role of NuSI.

Supported by the Nutrition Sciences Initiative…Nutrition Sciences Initiative (NuSI) convened the research team, helped formulate the hypothesis, and provided partial funding. NuSI and its scientific advisors were given the opportunity to comment on the study design and the manuscript, but the investigators retained full editorial control.

In this case, because I am familiar with the work of some of the investigators, I’m inclined to take these statements at face value.

Here’s what they did.  They put 17 overweight or obese men in a metabolic ward and fed them a very low carbohydrate diet, so low that it would induce fat breakdown and ketosis.  The calories were supposed to be sufficient to maintain weight, but were not.  The men lost weight from water excretion and breakdown of body protein as well as of fat, as is typical of what happens during partial starvation.  Energy expenditure did not increase to the level anticipated from the carbohydrate-insulin model.

The Abstract concluded:

The isocaloric KD [ketogenic, very low carbohydrate diet] was not accompanied by increased body fat loss but was associated with relatively small increases in EE [energy expenditure] that were near the limits of detection [translation: barely detectable] with the use of state-of-the-art technology.

The Discussion concluded:

Therefore, our data do not support the carbohydrate–insulin model predictions of physiologically relevant increases in EE or greater body fat loss in response to an isocaloric KD. However, it is possible that dietary carbohydrate restriction might result in decreased ad libitum energy intake—a prediction of the carbohydrate-insulin model that was not tested in the current study but deserves further investigation.

In other words, restricting carbohydrate does not increase body fat loss or energy expenditure but might help you eat fewer calories.

This result confirms some of the results of a previous study from the first NuSI author. That one, funded by NIH, concluded:

Whereas carbohydrate restriction led to sustained increases in fat oxidation and loss of 53 ± 6 g/day of body fat, fat oxidation was unchanged by fat restriction, leading to 89 ± 6 g/day of fat loss, and was significantly greater than carbohydrate restriction (p = 0.002).

Taken together, these studies show that both low-carbohydrate and low-fat diets cause weight loss when calories are restricted, but low-fat diets cause greater losses in body fat content than do low-carbohydrate diets.

In my book with Malden Nesheim, Why Calories Count: From Science to Politics, we review a 1964 study that put obese patients in a metabolic ward and fed them low-calorie diets of widely varied composition.  They lost weight at the same rate on diets ranging from 3% to 60% carbohydrate and from 13% to 83% fat.  They titled the study “Calories Do Count.”  The NuSI studies confirm the benefits of reducing calories from any source to lose weight.

Bottom line:

• With regard to weight loss, calories count and the relative proportions of fat, protein, and carbohydrate do not matter much (although low-carb diets may help with eating less).
• With regard to health, the food sources of calories matter very much indeed, and nearly everyone would be better off eating less sugar—at the very least because sugars provide calories, but no nutrients.

*Note: this version corrects an error in the version originally posted.  Hall et al.’s 2015 study was funded by NIH, not NuSI.  Apologies.

I’ve just received a new report from USDA’s Economic Research Service, U.S. Food Commodity Consumption Broken Down by Demographics.  This looks at trends in per capita food availability—the amounts of specific foods available in the food supply, obtained from data on production and imports, from 1994 to 2008, corrected for waste, per person in the United States.

Food availability data, especially when corrected for waste, suggest trends in per capita consumption patterns (otherwise why would USDA bother to collect them?), but they are not consumption data.  They are about supply, not use.

With that said, the trends seem odd to me.  They demonstrate a decline in the availability of:

• Fruit (mainly oranges)
• Vegetables
• Dairy (mainly milk)
• Beef
• Pork
• Potatoes
• Sugars

The supply of yogurt and cheese, however, has increased (but their per capita availability is relatively low).

The supply of apple juice also has increased:

Food availability data corrected for waste are supposed to come close to what people actually eat.  But if people are eating less of practically all foods, how come so many of us are still gaining weight?  Surely it’s not because of apple juice.

These data are an important source of information on U.S. dietary patterns.

But what do they mean?  The authors do not say, so it’s left to us to figure that out.

As I keep saying, finding out what people eat is the single most intellectually challenging problem in the field of nutrition.

Food-Navigator USA publishes occasional “special editions” with collections of articles on similar topics.  This one is on how food companies are dealing with weight management: “With almost two thirds of Americans overweight or obese, weight management is still a huge market opportunity for food and beverage manufacturers. However, messaging is moving away from diet-based concepts to more positive messages about food quality, satiety, and overall health & wellness.”

•  Back to Nature Foods Co. repositions SnackWell’s as a “free-from” line: Back to Nature Foods Co.’s revitalization of the recently acquired iconic SnackWell’s brand is an example of how established companies can refresh aging brands that are struggling to better compete with new products from disruptive startups… Watch now

A nutrient profiling system for the (re)formulation of a global food and beverage portfolio.  Antonis Vlassopoulos · Gabriel Masset · Veronique Rheiner Charles ·Cassandra Hoover · Caroline Chesneau‑Guillemont · Fabienne Leroy ·Undine Lehmann · Jörg Spieldenner · E‑Siong Tee · Mike Gibney ·Adam Drewnowski.  Eur J Nutr DOI 0.1007/s00394-016-1161-9.

• Conclusions:  The NNPS sets feasible and yet challenging targets for public health-oriented reformulation of a varied product portfolio; its application was associated with improved nutrient density in eight major food categories in the USA and France.
• Funding: The research presented herein was funded by Nestec Ltd, which is a wholly owned affiliate of Nestlé S.A.  The first eight authors are employed by Nestlé.
• Comment: the paper is the basis of a Nestlé infographic.

Including whey protein and whey permeate in ready-to-use supplementary food improves recovery rates in children with moderate acute malnutrition: a randomized, double-blind clinical trial.  Heather C Stobaugh, Kelsey N Ryan, Julie A Kennedy, Jennifer B Grise, Audrey H Crocker, Chrissie Thakwalakwa, Patricia E Litkowski, Kenneth M Maleta, Mark J Manary, and Indi Trehan.  Am J Clin Nutr  First published February 10, 2016, doi: 10.3945/​ajcn.115.124636.

• Conclusion: This study highlights the importance of milk protein in the treatment of MAM, because the use of a novel whey RUSF resulted in higher recovery rates and improved growth than did soy RUSF [ready-to-use supplemental food], although the whey RUSF supplement provided less total protein and energy than the soy RUSF.
• Funding for this project was provided by the Danish Dairy Research Foundation, Arla Foods Ingredients Group P/S, and the US Dairy Export Council. IT was supported by the Children’s Discovery Institute of Washington University in St. Louis and St. Louis Children’s Hospital…The funders had no role in the design or implementation of the study and no role in the analysis or interpretation of the data.

Oral health promotion: the economic benefits to the NHS of increased use of sugarfree gum in the UK.  L. Claxton, M. Taylor & E. Kay.  British Dental Journal 220, 121 – 127 (2016).  Published online: 12 February 2016 | doi:10.1038/sj.bdj.2016.94

• Conclusion If all members of the UK 12-year-old population chewed SFG frequently (twice a day), the potential cost savings for the cohort over the course of one year were estimated to range from £1.2 to £3.3 million and if they chewed three times a day, £8.2 million could be saved each year…This study shows that if levels of SFG usage in the teenage population in the UK could be increased, substantial cost savings might be achieved.
• Declaration: This study and writing support for the manuscript were funded by Wrigley Oral Healthcare Programme.

Dietary carbohydrate restriction as the first approach in diabetes management: Critical review and evidence base Richard D. Feinman, Wendy K. Pogozelski , Arne Astrup M.D., Richard K. Bernstein M.D., Eugene J. Fine M.S., M.D. , Eric C. Westman M.D., M.H.S.  , Anthony Accurso M.D. , Lynda Frassetto M.D.  , Barbara A. Gower Ph.D.  , Samy I. McFarlane M.D.  , Jörgen Vesti Nielsen M.D.  , Thure Krarup M.D. , Laura Saslow Ph.D. , Karl S. Roth M.D. , Mary C. Vernon M.D. , Jeff S. Volek R.D., Ph.D. , Gilbert B. Wilshire M.D. , Annika Dahlqvist M.D.r , Ralf Sundberg M.D., Ph.D.  , Ann Childers M.D.  , Katharine Morrison M.R.C.G.P.  , Anssi H. Manninen M.H.S.  , Hussain M. Dashti M.D., Ph.D., F.A.C.S.,  F.I.C.S., Richard J. Wood Ph.D., Jay Wortman M.D. , Nicolai Worm Ph.D.  Nutrition. January 2015 Volume 31, Issue 1, Pages 1–13 DOI: http://dx.doi.org/10.1016/j.nut.2014.06.011

• Conclusion: Here we present 12 points of evidence supporting the use of low-carbohydrate diets as the first approach to treating type 2 diabetes and as the most effective adjunct to pharmacology in type 1.
• Disclosure: AA is consultant/member of advisory boards for the Dutch Beer Knowledge Institute, NL, Global Dairy Platform, USA, Jenny Craig, USA, McCain Foods Limited, USA, McDonald’s, USA, and Gerson Lehrman Group, USA (ad hoc consultant for clients). He is recipient of honoraria and travel grants as speaker for a wide range of Danish and international concerns. He has conducted research funded by a number of organizations with interests in the food production and marketing sector. RDF writes reviews for Fleishman-Hillard, whose client is the Corn Refiners Association and he has received grant support from the Veronica and Robert C. Atkins Foundation. EJF has received grant support from the Veronica and Robert C. Atkins Foundation. TK sits on an advisory board for Eli Lilly and gives lectures for Lilly about the diabetic diet. NW has written popular-audience books on low-carbohydrate diets and is a consultant and promoter for Leberfasten/Hepafast, a specific low-carbohydrate meal replacement program. JW is on the Scientific Advisory Board of Atkins Nutritionals Inc. with paid retainer, honoraria, and travel costs. None of the other authors have anything to declare.
• Comment: The Atkins Diet is low-carbohydrate.

Comparison of Commercial and Self-Initiated Weight Loss Programs in People With Prediabetes: A Randomized Control Trial David G. Marrero, PhD, Kelly N. B. Palmer, MHS, Erin O. Phillips, BA, Karen Miller-Kovach, EBMA, MS, Gary D. Foster, PhD, and Chandan K. Saha, PhD. Am J Public Health. Published online ahead of print February 18, 2016: e1–e8. doi:10.2105/AJPH.2015.303035

• Conclusions. A large weight-management program is effective for achieving lifestyle changes associated with diabetes prevention. Such programs could significantly increase the availability of diabetes prevention programs worldwide making an immediate and significant public health impact.
• Funding: This study was funded by Weight Watchers International.

It’s close to a year since I first started collecting these studies.  When the year is up, I will do some analysis.  Until then, the bottom line is that it’s easier to find industry-funded studies with results favorable to the sponsor than it is to find those that are not.