Basket of Fruits

Obesity Causes: Thoughts on Food and Activity

The second day of the epic meeting on obesity causes at the Royal Society in London came round to the subject that preoccupies almost everyone – food and physical activity. One thing is certain. This is a pair of subjects that evokes strong passions, but the strength of the data often does not match the strength of convictions. As he opened the agenda for the day, Professor David Allison used the writing of Michael Strevens to make a point. Allison explained Strevens’ belief that Sir Isaac Newton was uniquely suited to bring in a new age of science:

“Newton was a closet unitarian working at Trinity College in an age when it was apparently new to hold one’s private religious views privately and one’s public views publicly, and separate those. Strevens argues that that duality allowed science to progress by allowing us to embrace our passions for our hypotheses, our drives to be right, our drives to compete, our intuitions, our zeal for some idea – privately. But then publicly commit to what he calls the iron rule of evidence.

“This is an area that is fun and exciting because lots of people disagree and that makes it a little bit intriguing. But when we disagree, we’re going to disagree on the evidence.”

Passions for Ideas

Allison clearly knew what to expect from this day. It began with David Ludwig passionately making his case that his carbohydrate insulin model can explain the stunning rise in obesity over the last four decades. Up front, he acknowledged that his model is provocative.

Moving through the day, we heard a whole litany of other well-reasoned and provocative ideas. The historical perspective that Kevin Hall offered on ultra-processed foods was especially fascinating – he described it as a just so story.

The day progressed with many more strong presentations on strongly held ideas. The panel discussion at mid-day was one of many highlights. The day closed with an excellent, skeptical presentation by Matthew Dalby about speculation on the role of microbiome in obesity.

The Lingering Question of Why?

In the lively discussion of this day, an apt comment stands out. Professor Jeffrey Friedman reminds us that we need to keep asking, why?

“Telling people to eat less and exercise more will not work. The question is, why does it not work? The available evidence is that there are biological factors that resist that conscious drive in most, not all people.”

Thanks to Mike Albert for pulling out that nugget.

Click here for more of the details on this superb meeting, here a few highlights of the first day, and here for the full video from day two. You can find excellent threads on twitter about the meeting here and here.

Basket of Fruits, painting by Edouard Manet / WikiArt

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October 19, 2022

One Response to “Obesity Causes: Thoughts on Food and Activity”

  1. October 19, 2022 at 8:23 am, Mary-Jo said:

    Thanks for the posts on this meeting, Ted. I’m trying to keep up and having the highlights here is helpful. Once a person is obese or a person with a strong predisposition with obesity (genetic and/or inter-generational ‘epigenetic’ changes of cultural, environment factors), the biology, indeed, makes managing obesity so very difficult, really almost impossible. IMO, the evidence of this should not be an excuse to give a pass to not making meaningful changes to make food and activity options more health-promoting, from all stakeholders involved. Even people with better odds of not becoming obese, are becoming obese! In some countries, changes have to be rather drastic. Other places, it’s easier to not become overweight. Just one example — I’ve been stateside, when going to restaurants, not fast food types, I have gotten French fries 3 times with my sandwiches, even when I didn’t order them! I’m overweight, I’m weak, my biology is screaming, of course I ate them! All I’m saying, we CAN make eating better and increasing activity HELP if we work harder at systemic changes to make better habits more normalized, not unattainably, impossibly ‘virtuous’. JMHO.