Rethinking nutrition science: the evolving landscape of obesity treatment, GLP-1 agonists, protein, and the need for higher research standards | David Allison, Ph.D.

**Peter Attia** (0:11)
Hey everyone, welcome to the Drive podcast. I'm your host, Peter Attia. This podcast, my website and my weekly newsletter all focus on the goal of translating the science of longevity into something accessible for everyone. Our goal is to provide the best content in health and wellness, and we've established a great team of analysts to make this happen. It is extremely important to me to provide all of this content without relying on paid ads. To do this, our work is made entirely possible by our members, and in return, we offer exclusive member-only content and benefits above and beyond what is available for free. If you want to take your knowledge of this space to the next level, it's our goal to ensure members get back much more than the price of the subscription. If you want to learn more about the benefits of our premium membership, head over to peterattiamd.com/subscribe. My guest this week is David Allison, who returns to the drive for a second sit down. David is currently the Dean and Provost Professor at the Indiana University Bloomington School of Public Health. He's authored over 500 scientific publications and received many awards and his research interests include obesity and nutrition, quantitative genetics, clinical trials, statistical and research methodology, and research rigor and integrity. In our conversation today, we discussed the relationship between nutrition, obesity, and body composition, and how food affects body composition beyond caloric intake. This leads us to a discussion around the complexity of nutrition research studies and how confusion continues to remain with translating knowledge into practical outcomes such as reducing obesity. We talk about the public health efforts and policy and why they have failed historically in regard to obesity and why there's such a trust problem with nutrition science. Next we dive into the emergence of GLP-1 agonists in treating obesity and what is happening both socially and psychologically with drugs like Ozempic and Mounjaro. We end the discussion talking about protein intake and the adequacy of current protein intake recommendations and the research gaps that lie between what we are told and maybe what is actually known. Overall, this was a fascinating and philosophical at times discussion on the evolving landscape of nutrition science, obesity treatment and the impact of research. Without further delay, please enjoy my conversation with David Allison.
David, good to see you once again.

**David Allison** (2:39)
Good to see you, my friend.

**Peter Attia** (2:40)
Lots to talk about today. The world of nutrition and health are always in the spotlight. In particular, around a class of drugs that no listener to this podcast will be a stranger to called GLP-1 agonists. I want to spend some time talking about those, but I think before doing so, I want to just maybe go back and talk a little bit about what we know and maybe don't know about the relationship between nutrition and obesity, which sounds like it should be obvious. Tell us what you think is actually known about the relationship between food and body composition.

**David Allison** (3:18)
I like the way you phrased the question and using the word body, the phrase body composition as opposed to just obesity or weight. There are obviously three different things. Obesity implies a threshold or too much. There's a judgment about the effects of the excess. Then there's body composition, the tissue, how much is fat, how much is lean, where is the fat lean, what is the fat composed of, what is the lean composed of. Then there's just weight, which is just your mass on this planet. Those three things are highly related, but not identical. What we know indisputably and even people who sort of rail against something they call the energy balance model, which you and I have discussed, whether it's really a model is unclear. It's really more of a constraint. It's really a restatement of the first law of thermodynamics, which is the law of conservation. Matter and energy can either be created or destroyed, but only converted. It is a constraint by which all other descriptions of what happens with weight and mass and food intake and energy and take an energy expenditure must operate. It's not a description or an explanation of what happens. It just says, if you describe any proposed explanation of what happens, it's got to follow that first law of thermodynamics in order to make sense. That first law of thermodynamics in the field of nutritional obesity often gets stated as something like changes in energy storage equal changes in energy intake minus changes in energy output, or delta energy stores equals delta energy in minus delta energy out. Food intake can affect those things. Alternatively, you could say that energy intake is one of those things. It gets back to that descriptive thing. Now, one of the questions becomes, how does all the other aspects of food besides the mere energy content of it, affect the amount of weight one gains or loses?