Currently browsing posts about: Diets

This is one of an ongoing series of examples of how industry funding skews, or to be more precise, is strongly associated with skewing, of research and opinion about matters of diet and health.

This example is an analysis of the scientific rigor of dietary approaches to controlling type 2 diabetes through diet.  The authors looked at the evidence for efficacy of the DASH, Mediterranean, Plant-Based, and Low-Carb diets.

Improving the Scientific Rigor of Nutritional Recommendations for Adults with Diabetes: A Comprehensive Review of the American Diabetes Association Guidelines Recommended Eating Patterns.  Hallberg S, Dockter NE, Kushner J, Athinarayanan S.  Preprints 2019.  Online March 5.  doi: 10.20944/preprints201812.0187.v2

Conclusion: “Our review of the current Standards and Recommendations finds significant shortcomings regarding scientific review methodologies, which are likely to translate to suboptimal clinical care decisions for patients with T2D.”  The study dismisses most studies of the DASH, Mediterranean, and Plant-based diets as poorly done or otherwise inappropriate for their review.  For the DASH diet, it says more research is needed.  It calls for more research on whether the benefits of Mediterranean diets are due to low carb or healthy fats, and suggests that the benefits of plant-based diets may be due to weight loss.  The best evidence supports the Low-Carb diet: “Evidence from 30 trials and 10 follow-up studies demonstrates that a low-carbohydrate diet is an effective dietary approach for addressing dyslipidemia.”

Conflict of Interest Statement:  SJH is an employee and shareholder of Virta Health, a for-profit company that provides remote diabetes care using a low-carbohydrate nutrition intervention, and serves as an advisor for Atkins Corp.  NED is a paid consultant for Virta Health.  JAK serves as medical director of McNair Interests, a private equity group with investments in type 1 diabetes and other chronic illnesses, and is also an advisor for Sanofi and Lexicon.

Comment:    All authors are employed by or consult for a company that uses low-carb dietary approaches in its for-profit business.  As I explain in Unsavory Truth, the influence of industry funding is often unconscious, unintentional, and unrecognized.  Nevertheless, the opinions of the authors can be predicted from their financial connections to Virta Health.

Nico Slate.  Gandhi’s Search for the Perfect Diet: Eating with the World in Mind.  University of Washington Press, 2019.  

Let’s start with my blurb:

Nico Slate’s fascinating account reveals Gandhi as an evidence-based, self-experimenting nutrition guru who tried one diet after another—vegan, raw, calorie restriction–in his quest for physical and spiritual health.  Above all, Slate explains Gandhi’s use of fasting as a political means to inspire India to achieve independence.

Gandhi, it seems, was a food faddist well ahead of his time.  The author says:

As his commitment to vegetarianism deepened, Gandhi grappled with whether he should also forgo eggs and milk.  Ultimately, he became convinced that he should become vegan, and renounced all animal products.  Living without eggs was relatively easy.  Doing without milk, by contrast, proved to be one of the greatest challenges of his life.  He experimented with almond milk, peanut milk, and other vegan alternatives.  In 1914, he vowed to abstain from all dairy products.  But after contracting a serious illness, he decided that his pledge did not include goat’s milk. [p. 47]

The book explains how Gandhi’s dietary choices were tightly linked to his politics.

The social potential of a raw diet led Gandhi to explore the cheapest source of sustenance for the poor: wild food…The greatest ethical challenge stemmed from the limitations of wild food as a remedy for poverty.  If the goal was to end hunger, changes in diet would be insufficient if they were not linked to changes in land ownership and the distribution of wealth—change that seemed as impossible as eating ginger nonviolently. [ p. 97]

And one more:

In a world marred by inequality, charity could only do so much.  Ultimately, Gandhi did not want to help the poor; he wanted to end poverty.  Over time, he developed a deeper understanding of the link between famine and imperialism.  “India suffers from starvation because there is dearth not of grain,” he explained, “but of purchasing power.”  The absence of purchasing power was, in turn, a direct result of the economic structures of British rule…Recognizing famine as a result of empire inspired Gandhi to demand India’s freedom. [p.127]

I’ve long argued that the most intellectually challenging issue in the field of nutrition is finding out what people eat.

Here’s what it takes:  Using DNA technology, investigators examined the stomach contents of the “Iceman,” a man who died 5300 years ago but was frozen in the Alps until his body was discovered some years ago.

The result: “a remarkably high proportion of fat in his diet, supplemented with fresh or dried wild meat, cereals, and traces of toxic bracken.”

A recent radiological re-examination of the Iceman, a 5,300-year-old European natural ice mummy, identified his completely filled stomach (Figure 1A) [2]…Previous isotopic analysis (¹⁵N/¹⁴N) of the Iceman’s hair suggested first a vegetarian lifestyle [12, 13] which was later, after careful re-examination of the data, changed to a omnivorous diet [14]. Further analyses of lower intestinal tract samples of the Iceman confirmed that he was omnivorous, with a diet consisting of both wild animal and plant material. Among the plant remains, there were cereals, pollen grains of hop-hornbeam, and fragments of bracken and mosses [14, 15, 16, 17, 18, 19, 20]… In summary, the Iceman’s last meal was a well-balanced mix of carbohydrates, proteins, and lipids, perfectly adjusted to the energetic requirements of his high-altitude trekking.

Nearly half (46%) of the bulk stomach contents consisted of animal fat, much of it saturated.  This, apparently, had consequences:

computed tomography scans of the Iceman showed major calcifications in arteria and the aorta indicating an already advanced atherosclerotic disease state [33].

Fascinating, no?  Now if we could do this kind of analysis on a population basis, think of the questions we could finally answer!

I’ve saved this for Weekend Reading because it will take a weekend to get through it.  The report is a blockbuster: 37 authors, 47 pages, 357 references.

The Lancet commissioned this report from the EAT Forum, which brought together international experts on diet and health (most of whom I do not know) to define unifying dietary principles that best promote will promote the health of people and the planet.

Fortunately, the diet that is best for health is the same diet as is best for the planet.  The report defines it on page 5.

To summarize:

This report has many strengths:

• It is researched in depth and is now the reference source for information about needed dietary changes.
• It firmly links dietary health to environmental sustainability.
• Its findings are consistent with many previous reports on diet and health, including that of the 2015 Dietary Guidelines Advisory Committee DGAC).
• Its messages are unambiguous.
• The summary report is a big help
• The timing  is excellent; the 2020 Dietary Guidelines advisory committee, if it ever gets appointed, will have to pay close attention to the science reviewed in this report.
• It focuses on food, not nutrients (these meals meet the standards of recommended diets).

Does this report settle the questions?  Hardly.  Remember the fuss over sustainability (the “S-word?”) in the 2015 report of the DGAC?

• The meat industry does not like advice to eat less meat.
• The dairy industry doesn’t like it either.  Its trade associations emphasize its nutritional value and source of livelihood for a billion people.
• The food industry has lots of complaints.

There is lots to read and think about here.  Enjoy!

• The Lancet home page for the report (includes slides, links)
• The Lancet editorial accompanying the report
• The EAT Forum home page for the report (information about EAT, the launch, the commission members, etc)
• The EAT Forum summary report

Lisa R. Young.  Finally Full, Finally Slim: 30 Days to Permanent Weight Loss One Portion at a Time.  Center Street, 2019.

I don’t usually write about diet books, but Lisa Young did her doctorate with me and I have followed her subsequent career with great interest.  She has taught for years in my NYU department and has a lively private practice counseling clients about weight loss and other nutrition issues.

Her book explains what works best with her clients.  She must be fun to work with.  The writing is warm, friendly, and to the point.  Her advice is easy and sensible: eat what you like (especially of healthy foods), just not too much.   She is generous with tips about how to deal with parties, restaurants, and other challenging situations, what she categorizes as “slices of advice,” “bite-size goodies,” and “wedges of wisdom.”

Her main focus is on portion control:

Portion control is like a classic wardrobe: It never goes out of style.  It’s not a trendy fad but a proven method for healthful living.  When you enjoy balanced meals and nutritious foods in appropriate portion sizes, you can get off the weight-loss merry-go-found.  So go ahead and enjoy a glass of wine or an occasional ice cream cone (a single scoop!).  Eat brown rice, quinoa, and other healthy carbs.  It’s not only okay.  It’s the best way to achieve long-term weight loss and maintenance.

Good advice, and easy to take.

No wonder its getting such great press.

• She’s on the cover of the January 2 New York Post, with much more about the book on pages 25, 26, and 27.
• Here’s an interview Lisa did in September.
• And here’s one she just did with Diet Detective.

In a most unusual action, the New England Journal of Medicine has retracted a 2013 study of Mediterranean diets and published a new version of it at the same time.

The studies asked participants to consume one of three diets: (1) a Mediterranean diet supplemented with extra-virgin olive oil, (2) a Mediterranean diet supplemented with mixed nuts, and (3) a control diet with advice to reduce dietary fat.

The authors describe Mediterranean diets as containing a

high intake of olive oil, fruit, nuts, vegetables, and cereals; a moderate intake of fish and poultry; a low intake of dairy products, red meat, processed meats, and sweets; and wine in moderation, consumed with meals.

The conclusion of the original, widely publicized, but now retracted study:

In this study involving persons at high cardiovascular risk, the incidence of major cardiovascular events was lower among those assigned to a Mediterranean diet supplemented with extra-virgin olive oil or nuts than among those assigned to a reduced-fat diet.

The conclusion of the newly analyzed version:

In this study involving persons at high cardiovascular risk, the incidence of major cardiovascular events was lower among those assigned to a Mediterranean diet supplemented with extra-virgin olive oil or nuts than among those assigned to a reduced-fat diet.

Looks the same, no?

The most thorough analysis of the study that I have seen comes from Hilda Bastian at PLoS Blogs.

Even for the full group, there was no statistically significant difference on myocardial infarction or CVD mortality – just for stroke. And in the supplementary information, there wasn’t a difference in the Kaplan Meier analysis for stroke either.

What are we to make of all this?

Diet trials are notoriously difficult to conduct and interpret and the Mediterranean diet—largely vegetarian with olive oil as the principal fat—was associated with great health and longevity based on studies of people who lived on the island of Crete immediately after the Second World War; they did not have much food to eat and were highly physically active.

And then there’s the matter of who paid for the study.  The retracted study and its revision were funded independently.  But a study published on June 13 concludes:

Adults who are overweight or moderately obese may improve multiple cardiometabolic disease risk factors by adopting a Mediterranean-style eating pattern with or without reductions in red meat intake when red meats are lean and unprocessed.

The funder?  The Beef Checkoff and the National Pork Board.

Overall, the 2015-2020 Dietary Guidelines for Americans recommends Mediterranean dietary patterns for their health benefits, defines what goes into them in Table 1.2 (p. 35), and provides more details in Appendix 4 (starting on p. 83).

Mediterranean diets are delicious.  While the scientists are arguing about exactly how healthy they might be, enjoy!

A reader in South Africa, Effie Schultz, sends an item from NutraIngredients-USA about a new meal replacement product, Bear Squeeze, “packed with MCT [medium-chain triglyceride] oil, kale, pumpkin seed protein and probiotics.”  It is aimed at people on ketogenic (very low carbohydrate) diets.

The president of the company that makes this product, Max Baumann, says that he wants Bear Squeeze to be known as a “higher-end, cleaner Soylent.”

NutraIngredients says:

If there’s any indicator that a large group of consumers are stoked about a meal replacement powder formulated to meet the requirements of a ketogenic diet, let that be California-based Bear Squeeze’s performance on fundraising platform Indiegogo,​ ​where it raised 421% of its $25,000 goal, a good month before its fundraising deadline.

The brand also snagged the top prize​​ at the new beverage showdown competition at BevNET Live last month, showing that Baumann has gotten the industry excited about his brand as well.

Why this product?  There is money—lots of it—to be made, apparently.

The impetus to start Bear Squeeze,…was seeing the success of meal replacement brands like Soylent, which recently moved from exclusively digital to brick-and-mortar. Soylent CEO Bryan Crowley said last month that sales performance in the offline channel “blew away expectations.”​​​

I have to confess not getting this.  With plenty of healthy, delicious food around, and at a cost buyers of products like these can well afford, why would anyone want to substitute something that tastes pretty awful (I’ve tasted Soylent and doubt this can be much better) for fabulous food?  People who consume these products must not be foodies, alas.

Medium-chain triglycerides are easy-to-digest fats created and formulated for hospitalized patients with serious digestive difficulties.

I vote for food, glorious food, anytime.

Adrienne Rose Bitar.  Diet and the Disease of Civilization.  Rutgers University Press, 2017.

I did a blurb for this one:

Bitar’s fascinating thesis is that diet books are ways to understand contemporary social and political movements.  Whether or not you agree with her provocative arguments, they are well worth reading.

I also took some extra notes because the publisher wanted a particularly short blurb.  As you might suspect from my brief comment, I have some quibbles with some of Bitar’s arguments, but the book is interesting, well written, and worth a look.

Bitar deals with four categories of diet books: Paleolithic, faith-based, South Seas paradise, and detox (this last category strangely includes Michael Pollan’s and my work).

Here’s a sample from the chapter I thought strongest, the one on Paleolithic diets.  It refers to classic images of man arising from apes, and then degenerating into obesity.

These images suggest what is much more explicit in the text—that the diet is a story about humanity, about evolution, about civilization and dis-mankind.  The body of the individual dieter is situated in a long, deep history of mankind.  The dieter is biologically indebted to the Paleolithic Era and, in turn, the coming generations will be indebted to him.  Everyday body practices of the individual—eating, sleeping, walking—are elevated to symbols of mankind’s ascent or descent, failures or triumph, in the grand narrative of progress (p. 41).