by Marion Nestle

Currently browsing posts about: Obesity

Apr 17 2020

Weekend reading: research on coronavirus and food

Research on this virus (officially SARS CoV-2, commonly COVID-19) is pouring out and filling every medical journal I typically read.  Here are a few recent articles on food-related aspects (some of these are not yet in print).

Obesity and its Implications for COVID-19 Mortality: The authors argue that the increased prevalence of obesity in Italy older adults as compared to its prevalence in China may account for the higher mortality observed in Italy.

Obesity is associated with decreased expiratory reserve volume, functional capacity and respiratory system compliance. In patients with increased abdominal obesity, pulmonary function is further compromised in supine patients by decreased aphragmatic excursion, making ventilation more difficult. Furthermore, increased inflammatory cytokines associated with obesity may contribute to the increased morbidity associated with obesity in COVID-19 infections.

Sudden and Complete Olfactory Loss Function as a Possible Symptom of COVID-19: This is a case study of a patient infected by SARS-CoV-2 whose presenting symptom was the sudden and complete loss of the ability to smell.

Loss of smell and taste in combination with other symptoms is a strong predictor of COVID-19 infection:  “Our study suggests that loss of taste and smell is a strong predictor of having been infected by the COVID-19 virus. Also, the combination of symptoms that could be used to identify and isolate individuals includes anosmia, fever, persistent cough, diarrhoea, fatigue, abdominal pain and loss of appetite.”

COVID‐19 Related School Closings and Risk of Weight Gain Among Children:  “In short, we anticipate that the COVID‐19 pandemic will likely double out‐of‐school time this year for many children in the U.S. and will exacerbate the risk factors for weight gain associated with summer recess.”

Should COVID-19 Concern Nephrologists?  Why and to What Extent? The Emerging Impasse of Angiotensin Blockade:  This is the easiest-to-understand review of the science of this extensively studied virus I have been able to find.  It covers the basics along with detailed explanations of what this virus does, how it works, and where vaccines might operate.    To penetrate human cells, this virus seems to hijack a particular enzyme in the complicated renin-angiotensin system that regulates body fluid balance and blood pressure.

Despite these differences, several studies have reported that SARS-CoV-2 exploits the same membrane-bound angiotensin-converting enzyme 2 (ACE2) as SARS-CoV to gain access to its target cells, although it has greater binding affinity. ACE2 is a carboxypeptidase that preferentially removes carboxy-terminal hydrophobic or basic amino acids. ACE2 cleaves a single residue from angiotensin I (Ang I), generating Ang 1–9, and a single residue from angiotensin II (Ang II) to generate Ang 1–7, whose vasodilator, anti-proliferative, and anti-fibrotic functional effects oppose those of the Ang II generated by angiotensin converting enzyme (ACE).

Oct 15 2019

World Obesity: Three More Reports

Friday October 11 was World Obesity Day, which explains why so many groups are issuing reports on obesity prevalence, risks, costs, and prevention strategies.

I wrote about the one from the Trust for America’s Health, The State of Obesity, a few weeks ago.

Here are three more, just in.

1.  The Heavy Burden of Obesity: The Economics of Prevention.

This one was produced by the OECD (Organisation for Economic Co-operation and Development).  It finds: “Almost one in four people in OECD countries is currently obese. This epidemic has far-reaching consequences for individuals, society and the economy. Using microsimulation modelling, this book analyses the burden of obesity and overweight in 52 countries (including OECD, European Union and G20 countries), showing how overweight reduces life expectancy, increases healthcare costs, decreases workers’ productivity and lowers GDP.”

2.  Time to Solve Childhood Obesity   This is “An Independent Report by the Chief Medical Officer, 2019, Professor Dame Sally Davies in the U.K.  The cover deals with both cause and effect:

3.  State of Childhood Obesity: Helping All Children Grow Up Healthy.  The Robert Wood Johnson produced this one.

Its key findings:

  • Obesity rates for youth ages 10 to 17 did not change much from 2016 (15%-16%).
  • Racial and ethnic disparities persist as do disparities by income.
  • Mississippi had the highest overall youth obesity rate (25.4%); Utah had the lowest (8.7%).

Comment:  Obesity is a global problem, not just one for the U.S.  Plenty of policies exist that could help make healthier food choices easier and less expensive.  But as the Lancet Global Syndemic report so clearly explained, doing something about obesity is hampered by weak (corporate-captured) government, food industry opposition, and weak civil society.  The first two are difficult to do anything about without attention to the third.  The clear need: strengthen civil society.  Let’s get to work on that.

Sep 20 2019

Weekend reading: the state of obesity

Trust for America’s Health has just published its annual report on obesity, state by state.

As the home page puts it, “U.S. Obesity Rates Reach Historic Highs – Racial, Ethnic, Gender and Geographic Discrepancies Continue to Persist.”

The press release has an even more pointed headline: “U.S. Obesity Rates at Historic Highs – Nine States Reach Adult Obesity Rates of 35 Percent or More.”

The report highlights that obesity levels are closely tied to social and economic conditions and that individuals with lower incomes are more at risk. People of color, who are more likely to live in neighborhoods with few options for healthy foods and physical activity, and, are the target of widespread marketing of unhealthy foods, are at elevated risk.

What to do?

The report calls for sugary drink taxes, expanded SNAP and WIC Nutrition support programs and a built environment that encourages physical activity.

Buried in the report are suggestions for curbing food-industry marketing and other efforts to undermine public health initiatives.

  • Keep industry out of dietary guidelines.
  • Consider regulating food-industry marketing.
  • Stop industry from preempting state public health laws.
  • Reduce unhealthy food marketing to children.

Lots of good stuff here and well worth a read.

Aug 5 2019

Industry-funded study of the week: “probiotic” weight-loss supplement

I spotted some tweets about this study from Washington Post writer Tamar Haspel, who has a sharp eye for this sort of thing.  Her first tweet said:

Her second tweet explained the problem:

So of course I had to look up the study.  It’s not one I would ordinarily have noticed because its title does not use the word “probiotic,” which typically refers to the live bacteria (in yogurt, for example).  The evidence for benefits of probiotics is iffy, so this study raises lots of questions.

Let’s take a look at it:

The Study:  Supplementation with Akkermansia muciniphila in overweight and obese human volunteers: a proof-of-concept exploratory study. Depommier C, et al.  Nature Medicine (2019

Conclusion: I’ve left out the statistics to make this easier to read:  “Compared to placebo, pasteurized A. muciniphila improved insulin sensitivity…, and reduced insulinemia…and plasma total cholesterol…. Pasteurized A. muciniphila supplementation slightly decreased body weight…compared to the placebo group, and fat mass…and hip circumference…compared to baseline….In conclusion, this proof-of-concept study…shows that the intervention was safe and well tolerated and that supplementation with A. muciniphila improves several metabolic parameters.”

Competing interests:  Five of the authors “are inventors of patent applications…filed with [patent offices in at least 12 countries]…dealing with the use of A. muciniphila and its components in the context of obesity and related disorders.” Two of the authors are cofounders of A-Mansia Biotech S.A., a Belgian company that sells A. muciniphila supplements, presumably as weight-loss supplements.

Comment: As Haspel points out, the subjects in this study were given either (a) live bacteria, (b) Pasteurized (and, therefore, mostly dead) bacteria, or (c) a placebo.  The Pasteurized ones were associated with metabolic benefits and weight loss.  Pasteurization is what gets done to milk to kill most—not all—of the living bacteria it contains.  In this study, Pasteurized bacteria had the same effect on the microbiome as the unpasteurized.  The point of the study was to show that the Pasteurized supplement would induce weight loss; the observed loss, however, was not statistically significant.   Nature Medicine‘s editors should know better.  So should the New York Times’ editors.  Haspel points out that the New York Times account of the study accepted its conclusion uncritically, headlining it “A Probiotic for Obesity?”  At least the headline included a question mark.  The article did not mention the authors’ patents or conflicts of interest; it should have.

Bottom line: If you want to keep your microbiome healthy, eat a healthy diet.

May 21 2019

Obesity explained: Ultra-processed foods –> Calories –> Weight Gain

Kevin Hall at NIH has done a controlled diet study demonstrating that people who consume ultra-processed foods eat more calories—500 more a day (!)—and, therefore, gain weight.

Carlos Monteiro at the University of São Paulo and his colleagues explain how to identify ultra-processed foods.  

They also demonstrate that ultra-processed foods comprise nearly 60 percent of calorie intake.

No surprise.  Calories matter, as Mal Nesheim and I explained in our book Why Calories Count: From Science to Politics (and thanks Kevin for confirming what we wrote in that book).

The clear conclusions of this study have elicited a lot of attention.  Here’s my favorite from Francis Collins, the head of NIH and Kevin Hall’s boss, who also did a blog post:

Examples of media accounts (there were lots more)

Jan 28 2019

New Lancet report: The Global Syndemic: Uniting Actions to Address Obesity, Undernutrition, and Climate Change

The Lancet has been busy.  Last week, it published a blockbuster report on the need for worldwide dietary changes to improve human health and that of the environment.  I posted about this EAT-Forum report on Friday.

Now, The Lancet releases yet another report, this one taking a unified approach to dealing with the three most important nutrition issues facing the world: Malnutrition (undernutrition), obesity, and the effects of our food production and consumption system on the environment and climate change—for which this report coins a new term: The Global Syndemic.

This report breaks new ground in identifying the food industry as one of three main barriers to ending this “Syndemic.”  I’ve added the numbers for emphasis.

  • Powerful opposition by [1] commercial vested interests, [2] lack of political leadership, and [3] insufficient societal demand for change are preventing action on The Global Syndemic, with rising rates of obesity and greenhouse gas emissions, and stagnating rates of undernutrition.
  • New social movement for change and radical rethink of the relationship between policymakers, business, governance and civil society is urgently needed.
  • The Commission calls for a global treaty to limit the political influence of Big Food (a proposed Framework Convention on Food Systems – modelled on global conventions on tobacco and climate change); redirection of US$5 trillion in government subsidies away from harmful products and towards sustainable alternatives; and advocacy from civil society to break decades of policy inertia.

Wow.  This is telling it like it is—at long last.  From the press release:

  • A key recommendation from the Commission is the call to establish a new global treaty on food systems to limit the political influence of Big Food.
  • The food industry’s obstructive power is further enhanced by governance arrangements that legitimise industry participation in public policy development, and the power that big corporations have to punish or reward governments by relocating investment and jobs.
  • Regulatory approaches to product reformulation (eg. salt and sugar reduction), labelling and marketing to children are needed because industry-led, voluntary approaches have not been effective.

Yes!

The documents

The press

▪ The Guardian
The Times (London)
Irish Farmers Journal

Additional press, posted January 30

Newswires (syndicated in international outlets):

UK:

US:

Rest of world:

Jan 16 2019

Bad news on world hunger and obesity: they are getting worse

United Nations agencies have just released their annual report on world food insecurity.

Its main unhappy conclusion:

Food insecurity has increased since 2014:

So has worldwide obesity:

What is to be done?

Alas, that’s not what this report is about.

Dec 7 2018

Weekend reading: the 2018 Global Nutrition Report

If you want an overview of the current status of nutrition problems in the world, what is being done about them, and what needs to be done about them, this report is required reading (to get to the download button for the entire report, scroll to the end of the page).

The report is chock full of useful facts, figures, case studies, and recommendations.  A massive undertaking, it

was produced by the Independent Expert Group of the Global Nutrition Report, supported by the Global Nutrition Report Stakeholder Group and the Secretariat at Development Initiatives. The writing was led by the co-chairs Jessica Fanzo and Corinna Hawkes, supported by group members and supplemented by additional analysts and contributors.

For a quick overview, go right to the slide deck and then to the graphics in the executive summary.

The report deals both with problems of malnutrition (undernutrition) and obesity (overnutrition), especially in children.

It also deals with adult obesity:

It identifies measurable nutrition indicators that can be used to track progress:

It recommends actions to reduce the prevalence of malnutrition and obesity.

What stands in the way of implementing these steps?  Political will, alas.

These reports have come out annually since 2014.  Let’s hope this one gets the attention it deserves.