Blue Iris, Human Eye

Energy Balance: Physics or Biology?

David Ludwig and Sam KleinAn energetic and well-informed debate at the 2016 Blackburn Course in Obesity Medicine provided a deep dive yesterday into controversy regarding competing ideas about energy balance. Sam Klein presented the view that energy balance is an issue of physics. David Ludwig presented the view that it is an issue of biology.

Klein provided an entertaining defense of classic ideas about energy balance without resorting to simplistic clichés about calories in and calories out. His bottom line:

  • Energy balance drives body weight.
  • Regulation of energy intake by the brain is key.
  • Reward mechanisms control it in complex, poorly understood ways.

Always Hungry, David LudwigLudwig was a bit more definitive and equally entertaining. The more definitive view he presented was unsurprising, given his recent publication of Always Hungry?, a best-selling book. He summarized by saying:

Improving diet quality may be less difficult and more successful than cutting calories for long-term weight loss. A simple dietary strategy to lower insulin and promote weight loss is to replace highly-processed carbohydrates with healthy, high-fat foods – including nuts and nut butters, full-fat dairy, olive oil, rich sauces and spreads, and dark chocolate. We need much better research to definitively test this possibility.

In case you didn’t notice, they had the same ultimate point. We don’t know everything we need to know about nutrition and the regulation of body weight.

For more on this subject, check out Ludwig’s excellent book, as well as this outstanding summary on the subject by Kevin Hall, Sam Klein, and a host of other distinguished authors.

Blue Iris, Human Eye; photograph © Macroscopic Solutions / flickr

Subscribe by email to follow the accumulating evidence and observations that shape our view of health, obesity, and policy.


June 4, 2016

One Response to “Energy Balance: Physics or Biology?”

  1. June 08, 2016 at 12:03 pm, Allen Browne said:

    Yup – it was entertaining, but not a debate between two different points of view. The Blackburn Course, MARS Course, etc have made the physics approach hard to defend.