Diet Quality in the Era of High-Potency Weight Loss Drugs

Jeanette Brooks: Hi, and welcome to Medicine With a Fork, a podcast from the educational nonprofit Gaples Institute, whose mission is to advance the role of nutrition and lifestyle in medicine. I'm your host, Jeanette Brooks, and I'm joined today by our executive director, Dr Stephen Devries. He is a preventive cardiologist; he's also part of the faculty of the Harvard T.H. Chan School of Public Health in the Department of Nutrition. Hi, Steve.

Stephen Devries, MD: Hi, Jeanette. Great to be with you.

Brooks: Yeah, likewise! So Steve, I wanted to talk with you today because there's been a lot of buzz lately around this newest wave of anti-obesity medications that have emerged—and specifically, their effectiveness in helping patients who maybe historically have not had a lot of success with losing weight through just lifestyle changes alone.

So I wanted to pivot a little bit and talk with you about where that leaves the role of diet and just ask you: how relevant is diet quality for patients who are taking these newer weight-loss drugs and finding success with them?

Devries: That's a really important question to address. What's the role of diet quality in this new era of high-potency weight loss drugs? And for those working to lose weight, food choices have always been central. But with the availability of these new highly effective drugs, the question is, do food choices still matter? And the answer is a resounding yes.

Brooks: Yeah. We know of course that food choices have always been and continue to be an important driver of weight loss. So now that these potent GLP-1 agonists are on the scene, they're often producing a pretty dramatic weight loss, right? Like 15% or more? So what has been the impact, then, on the role of diet?

Devries: No question that these new agents have opened up unprecedented potential for weight loss. But here's a potential problem: with all of the attention on the new weight-loss meds, there might be a tendency to imagine that food choices may not be as consequential for patients who are already seeing such dramatic weight loss on the meds.

Brooks: So tell us more about why you feel diet quality deserves more attention, including for the people who are losing weight successfully on medication, or maybe those who have even gotten down to their target weight.

Devries: Diet quality remains a vital concern for everyone, including those on the newer weight-loss meds. First, it has to be acknowledged that GLP-1 agonists are highly effective therapies for weight loss and, when given to appropriately selected individuals, may reduce the morbidity and mortality associated with excess body weight. But what is also true is that even for individuals with a so-called “healthy” weight, the quality of the diet also greatly impacts health.

Brooks: Say a little bit more about that. For patients who have lost a significant amount, maybe even gotten to their goal weight, how can a higher quality diet make such a difference in their health?

Devries: To start with, let's put diet quality into perspective, and we can do that with the findings from the US Burden of Disease Collaborators study. Their study examined 17 risk factors that most contribute to death in the United States. Of all 17, high BMI was found to be the fourth greatest risk factor, but leading the list as the top risk factor for death was poor-quality diet.

Brooks: That's somewhat surprising, but good to put into perspective, that poor-quality diet was the one that led the list—even a stronger risk than high BMI. So, what else can you tell us then, Steve, about the impact of diet quality among patients who are now at their target weight? What about them?

Devries: There are two large studies that speak to that very point. The first is a Swedish study that examined the link between adherence to a Mediterranean-style diet and mortality. They looked at 79,000 individuals stratified by BMI and followed for 17 years. And just a parenthetical comment about the term BMI, since we're talking about that: although it's not a perfect measure of adiposity, as has been widely acknowledged recently, it remains still a useful—albeit incomplete—measure of excess weight.

Brooks: Thank you for saying that. I know there's been some discussion about how BMI does not account for every single driver of patient health, but what I'm hearing from you is that it's still an important piece of the puzzle, at least a starting point for understanding health status.

Devries: Exactly.

Brooks: So going back to that Swedish study, tell us what the research showed.

Devries: Sure. In the Swedish study, zeroing in on those with a so-called “normal” BMI, that is between 20 and 25, individuals who were least adherent to a Mediterranean diet had a 60% increased risk of death by any cause and a 76% increased risk of death from cardiovascular disease compared to those who were most adherent to a Mediterranean diet.

And when the data is expressed as number needed to treat, in the group of individuals with normal weight, the number needed to treat with a Mediterranean diet to prevent total mortality during the study was only 11.

Brooks: Wow. Okay. So can you give us a snapshot of, when you say Mediterranean diet, what were those patients eating exactly?

Devries: For sure. A Mediterranean-style diet is one that promotes the intake of vegetables, fruit, legumes, and nuts, emphasizes whole grains. And there can be a small amount of dairy products, typically fermented are emphasized, and a reduced intake certainly of red and processed meat.

Brooks: Okay, got it, thanks.

Devries: And on the flip side, it's important to point out that even the healthiest diet didn't remove the additional risk of cardiovascular mortality associated with obesity. So clearly the ideal is to have both a healthy body weight and a healthy diet. But also important to emphasize that at every body weight, the diet quality still mattered.

Brooks: Yeah, it seems very clear that the best outcomes involve both: a healthy weight, yes—and also this healthier diet.

Devries: That's for sure the case. The second study to highlight is U.S. data from the Lifetime Risk Pooling Project, which included over 30,000 participants followed for 16 years. Diet quality was measured with an alternative eating index and it was studied along with BMI and the association with cardiovascular disease was examined. After adjusting for covariates in those with normal weight, a healthy diet reduced the risk of incident cardiovascular disease by 21%, compared to those who consumed the least healthy diet.

Brooks: It's remarkable. More evidence, right, that just because a patient happens to be at their target weight, that doesn't always ensure the best health status. So Steve, you've walked us through some pretty persuasive data here about the importance of diet quality, even for patients who are successfully losing excess weight, or even those who have achieved their weight loss goals. Can you talk to us about what is happening now in this landscape of anti-obesity medications that makes this such an important message.

Devries: I think there's a very understandable excitement about the newer class of high-potency weight loss drugs. An agent that can achieve 15 to 20% weight loss truly opens up a world of possibilities for so many. But it seems with all the attention afforded to the new drugs, there can be a tendency to think that the health objectives have been met once substantial weight loss has been achieved.

And with the data we've talked about today, it's clear that is not the case. So when it comes to optimizing health outcomes, the job isn't necessarily complete when the weight loss is achieved. Especially now in this era of high-potency weight loss drugs, it's important not to lose sight of the fact that before, during, and after weight loss, the role of diet quality remains vitally important because diet quality continues to make a huge impact even after significant weight loss is achieved.

Brooks: I really like that notion that you shared, that the job isn't done just because a patient is done losing weight, right? It's really an ongoing job, this practice of getting healthy and staying healthy. And what about the long-term use of these new weight loss drugs? How do you see the role of diet for people who maybe stay on the meds for a long time?

Devries: Needless to say, it's vitally important to emphasize to patients that a high-quality diet remains an important goal while taking these meds. And there may be special attention needed to diet quality for patients who experience side effects from the newer agents, including nausea or disinterest in foods even has been reported. So patients need to know that the foods they consume are as important to their health as the ones they're avoiding.

And the other point to make is that we don't know how long patients will need to be maintained on these new weight loss drugs, right? We don't know if or how there will be an off ramp, but if there's a chance of getting people off the meds and maintaining weight loss, it will be important that they've established and maintained a healthy pattern of eating during the time they've been on the medications.

Brooks: Yeah, that's a great point that food is still a driver of patient health, a major driver, whether weight loss drugs are part of a patient's treatment plan or not.

Devries: Exactly.

Brooks: Steve, thank you so much for really bringing home this principle of diet quality. It's a super important one in helping patients along their health journey. And speaking of that for clinicians who are looking to sharpen their skills at talking to their patients about this topic of nutrition and lifestyle, the Gaples Institute does provide a self-paced interactive clinical nutrition course on the AMA Ed Hub, and AMA members can receive that for a discount.

It's four credits of nutrition CME, and it's full of not just nutrition data, but also practical real-world guidance on what it looks like to effectively counsel your patients toward healthier eating. You can learn more at NutritionForDocs.org.

Steve, thanks again for your insights today. It was really a pleasure to talk with you and for those listening, we look forward to connecting with you again on Medicine With a Fork.

© Copyright 2023 — Gaples Institute

Financial Support Disclosure Statement

Disclosures: Dr Devries is the salaried executive director and Jeanette Brooks is the salaried director of e-learning for the Gaples Institute, an educational nonprofit that offers accredited continuing medical education courses for sale to health professionals. Courses are developed entirely through philanthropy to the Gaples Institute, a nonprofit that does not seek or receive corporate support. Neither Dr Devries nor Jeanette Brooks receive royalties or personal consideration of any kind from the sale of these courses. This podcast was developed with no corporate support.