The Sleep-Weight Connection

Summary

JAMA Clinical Reviews – "The Sleep-Weight Connection"

Host: Dr. Mary McDermott (JAMA)
Guest: Dr. Atul Malhotra (UC San Diego)
Date: July 29, 2026

---

Episode Overview

This episode of JAMA Clinical Reviews explores the complex, evolving relationship between sleep and body weight. Dr. Mary McDermott interviews Dr. Atul Malhotra, a leading sleep and respiratory medicine expert, about the evidence linking inadequate or excessive sleep with weight gain and obesity, underlying biological mechanisms, impacts on weight loss efforts, clinical considerations (including sleep apnea), and the latest treatment options—including behavioral modifications and new pharmacologic interventions for obesity and sleep apnea.

---

Key Discussion Points & Insights

Association Between Sleep and Obesity

• Sleep as a Pillar of Health: Dr. Malhotra stresses that sleep, alongside diet and exercise, forms one of three critical health pillars, each influencing the others ([01:31]).
  • Quote: "If you ignore one, the other two will suffer." – Dr. Malhotra [01:36]
• Epidemiological Evidence: In landmark studies, such as the Nurses Health Study, habitually short sleepers (5-6 hours) gain more weight over time vs. those sleeping adequately, independent of other risk factors ([01:45]).
• Endocrine Mechanisms: Laboratory studies show sleep deprivation suppresses leptin (satiety hormone) and increases ghrelin (appetite-stimulating hormone), driving increased appetite and weight gain ([02:10]).
  • Quote: "Leptin levels are suppressed and ghrelin levels are increased with sleep deprivation, both hormones going in a direction that's predicted to stimulate appetite." – Dr. Malhotra [02:24]

Defining Adequate Sleep

• General Guidelines: 7–9 hours per 24-hour period is recommended for most adults ([02:46]).
• Individual Variability: Some variation exists, but most people claiming to function well on under 7 hours are "kidding themselves" ([03:00]).

Sleep's Impact on Weight Loss Efforts

• Evidence for Fat Loss Impairment: In a randomized controlled trial in the Annals of Internal Medicine, participants dieting while sleep deprived lost less fat compared to those with adequate sleep ([03:35]).
  • Quote: "If you're going on a diet, you need to sleep adequate duration for the diet to work properly, otherwise you don't lose as much fat." – Dr. Malhotra [03:54]

Directionality and Causation

• Randomized Trials Support Causality: Mechanistic and RCT data support poor sleep → weight gain, not just the other way around ([04:14]).

Mechanisms Beyond Hormones

• Complex Pathways: While changes in leptin and ghrelin are well-documented, sleep loss may also activate pro-inflammatory pathways and alter the autonomic nervous system ([04:53], [06:16]).
  • Quote: "Nobody craves salad at 3 o'clock in the morning." – Dr. Malhotra, on unhealthy food choices during sleep deprivation [05:06]
• Increased Opportunities to Eat: More waking hours can mean more eating opportunities, but hormonal and inflammatory changes are also significant ([05:46]).

Confounders and Causes of Short Sleep

• Social and Medical Factors: Insomnia, chronic pain (such as arthritis), social pressures (children, shift work), and unhelpful habits (late-night Netflix) contribute to inadequate sleep ([06:16], [07:11]).
• Universal Impact: Regardless of the cause, short sleep is consistently associated with adverse health outcomes ([06:35]).

Approach to Sleep and Obesity in Practice

• Patient Counseling: Emphasis on prioritizing sleep, sometimes before addressing diet, as a key to weight management ([07:11]).
• Obstructive Sleep Apnea Awareness: Obstructive sleep apnea (OSA) is prevalent in obesity; clinicians should screen for OSA in patients with snoring, excessive sleepiness, hypertension ([07:45]).
  • Quote: "We’ve estimated about a billion people worldwide with obstructive sleep apnea." – Dr. Malhotra [07:50]

Excessive Sleep and Health Risks

• Prolonged Sleep Associations: Oversleeping (12+ hours) also correlates with obesity, depression, and inflammatory disorders; possibly confounded by social isolation or underlying disease ([08:24]).
• Objective Evidence: Even when measured objectively, excessive sleep carries risk, likely reflecting other health conditions ([08:52]).

Treatments and Interventions

• Behavioral Sleep Therapies: Cognitive Behavioral Therapy for Insomnia (CBT-I) can be effective, focusing on sleep restriction and stimulus control ([09:22]).
• Diet and Exercise Limitations: While important, these alone are often insufficient; many patients require additional interventions ([09:56]).
• Pharmacologic Advances: Tirzepatide (dual GLP-1/GIP agonist), recently FDA approved, drives 18–20% weight loss and improves sleep apnea severity, blood pressure, inflammation, and quality of life ([10:14], [10:50]).
• Eligibility and Insurance Nuances: FDA approval for tirzepatide began with diabetes, expanded to obesity and then specifically for obesity with sleep apnea, with BMI cutoffs commonly used but not absolute ([11:18]).
• Effects Beyond OSA: No strong evidence yet that GLP-1 agonists improve sleep in overweight/obese people without OSA ([12:04]).
• Improving Sleep to Facilitate Weight Loss: Extending sleep in habitual short sleepers has been shown to help weight loss in interventional studies ([12:48]).

---

Notable Quotes & Memorable Moments

• "If you ignore one [pillar], the other two will suffer." – Dr. Malhotra, on the triad of sleep, diet, exercise [01:36]
• "Nobody craves salad at 3 o’clock in the morning." – Dr. Malhotra [05:06]
• "We’ve estimated about a billion people worldwide with obstructive sleep apnea. That number's increasing, not decreasing over time." – Dr. Malhotra [07:50]
• "If diet and exercise were highly effective, I would be skinnier." – Dr. Malhotra, humor on the need for adjunctive therapies [09:56]
• "I've had patients get divorced over snoring because their spouses are in different beds." – Dr. Malhotra, on the social impact of sleep apnea [13:36]

---

Timestamps for Important Segments

• 01:31 – Overview: Sleep and obesity relationship
• 02:41 – Defining adequate sleep
• 03:35 – Sleep deprivation’s impact on weight loss diets
• 04:14 – Causality and direction of association
• 04:53 – Biological mechanisms explained
• 06:16 – Clinical confounders for short sleep
• 07:11 – Approaching patients with obesity & sleep problems
• 07:45 – OSA as key clinical consideration
• 08:24 – Risks associated with excessive sleep
• 09:22 – Behavioral and pharmacological treatment options
• 10:14 – Tirzepatide clinical trial outcomes
• 11:18 – Clarifying FDA indications and insurance for tirzepatide
• 12:48 – Sleep extension facilitating weight loss

---

Take-Home Messages

• Sleep, diet, and exercise are equally fundamental for health—neglecting sleep undermines weight control and overall well-being.
• Both too little and too much sleep can be associated with obesity and health risks—adequate duration (7–9 hours) is key.
• Mechanistic and clinical data support a causal link from poor sleep to weight gain via hormonal and behavioral pathways.
• OSA is a major, underappreciated issue in obesity; screening and new therapies (GLP-1/GIP agonists, CPAP) can have significant health impact.
• Behavioral interventions like CBT-I plus new pharmaceuticals offer hope for improving sleep and weight outcomes.

---

For the full clinical review article discussed, see the episode description or visit JAMA Network Audio.

Transcript

[A]

Hi, I'm Derek Angus, a senior editor at JAMA and host of Healthy Dialogue, a new podcast from the JAMA Network. Join me as we go beyond the latest discoveries with nuanced, in depth conversations with the world's leading experts to explore the most pressing issues in health and healthcare, from trends in autism diagnosis to private Equity acquisition to AI and much, much more. Visit JamaneTWORKaudio.com or search Healthy Dialogue wherever you get your podcast to subscribe.

[B]

Welcome to listeners from around the world and thank you for tuning in to this JAMA Clinical Review podcast. I am your host, Dr. Mary McDermott, deputy editor of JAMA, and I'm here today with Dr. Atul Malhotra, who is Vice Chair of Research in the Department of Medicine, Research Chief for Pulmonary and Critical Care Sleep Medicine and Physiology at UC San Diego, and the Peter Farrell Tenured professor of Respiratory Medicine at UC San Diego. Welcome, Atul.

[C]

Thank you for having me.

[B]

Mary, can you start us off by discussing what is the association of sleep and obesity?

[C]

Yeah, thank you for the question. It turns out that sleep is a vital part of human health, perhaps not surprisingly, but the data are becoming more and more compelling that inadequate sleep has health consequences. Your mother was right. We think of three pillars of health being diet, exercise and sleep, with the dogma being if you ignore one, the other two will suffer. So they're pretty good data that people who are habitually sleep deprived will gain more weight over time than those who sleep adequately. We had a paper about 20 years ago now from the Nurses Health Study looking at inadequate sleepers. Those sleeping five or six hours per night gained more weight over time than those sleeping adequately. Independent of known covariates, there's a mechanistic work coming out of Evan Cotter's lab in Chicago that's given some insight into this. If you randomize individuals in laboratory to adequate sleep versus inadequate sleep, the leptin levels are suppressed and ghrelin levels are increased with sleep deprivation, both hormones going in a direction that's predicted to stimulate appetite. And so there may be a mechanistic link between why short sleep leads to weight gain and other metabolic risk.

[B]

Can you tell us what defines adequate sleep? How much sleep should people be getting in general?

[C]

You know, the definition of adequate sleep is a little tricky because it does vary by individuals. Different people have different needs. The vast majority of people who say, I don't need to sleep or I can stay up all night and function fine, the vast majority of them are incorrect. So the guidelines that we and others have put out suggest that seven to nine hours of sleep in a 24 hour period is recommended. And if you have fewer than seven hours is when you start to see health consequences. There are some individual variations, but the vast majority of people that say they function fine on five hours of sleep are kidding themselves.

[B]

Your insight describes some other high quality studies about this association. And there was one, for example, where you discussed that even for people trying to lose weight, that it's more difficult to lose weight when one is sleep deprived. Could you talk a little about that?

[C]

There was a paper in the Annals of Internal Medicine some years ago where they randomized individuals getting adequate sleep or inadequate sleep who are going on a diet. And the idea was if you're going on a diet, you need to sleep adequately for the diet to work. And in that paper they did observe reduced loss of fat in people who are sleep deprived compared to those who are sleep satiated while going on a diet. So it's something I tell my patients, if you're going on a diet, you need to sleep adequate duration for the diet to work properly, otherwise you don't lose as much fat.

[B]

And do we think the direction of the association is poor sleep, weight gain, or is it possible that the direction goes the other way?

[C]

These are randomized studies. The one in Annals of Internal Medicine, certainly. And so I don't think reverse causation is a big factor there because there's causal pathways that make sense that if you induce inadequate sleep there are health consequences, including, as I mentioned, suppressed leptin, increased ghrelin and reduced fat loss during diet.

[B]

I wonder if you could say a little bit more about the biology behind the association. Is it mainly the case that with sleep deprivation there's adverse levels of leptin and ghrelin that makes an individual more hungry, or are there other mechanisms as well?

[C]

Yeah, it is complex, Mary, and I think the short answer is we don't know for sure. Certainly leptin is a hormone that's made by adipocytes and it tells your hypothalamus to stop eating. So it's a satiety hormone. Ghrelin is the opposite. It's made in the GI tract and it stimulates appetite. And so increases in ghrelin and reductions in leptin would both be predicted to stimulate appetite. The interesting part of that though is there's sort of a joke. Nobody craves salad at 3 o' clock in the morning. And the reason that's interesting is people tend to crave the worst foods at odd hours, very salty foods. Or sugary foods, these kinds of things. I don't think that's well worked out as to why. But there are other biological mechanisms, Mary, as you're alluding to so pro inflammatory pathways, other things that may have health consequences that are induced with sleep deprivation. So the short story is the, you know, the story is still evolving here,

[B]

and based on your earlier comment, it sounds like some of the association could be if you're awake more hours, then you know, there's more opportunity to eat. But your point seems to be it's not only that. There's obviously these biologic pathways that you've mentioned as well. And your manuscript discusses some more clinically focused explanations, such as arthritis related pain at night that could make sleep difficult. Could you talk about that? Sure.

[C]

There are definitely confounders here in terms of why some people sleep short. Some have insomnia where they can't or won't sleep adequately. Some are burning the candle at both ends because they have young kids or multiple jobs or this kind of thing where they want to sleep more, but they can't because of social pressures. And then there's some that short sleep because they think that's all they need. As best we can tell from the literature, short sleep has health consequences regardless of why it's occurring. And so it's not so much a matter of why you're sleeping short, but the fact that you're sleeping short has health consequences. And yeah, there are lots of factors that can come into play in terms of why that's occurring. The other thing to think about, by the way, is the autonomic nervous system. With short sleep, there's sympatho excitation, other things that can have biological consequences as well, and health consequences.

[B]

And so for your patients who have obesity and also sleep difficulty, how do you approach this problem? Often when people have sleep difficulty, it's not so easy to fix that problem.

[C]

Yeah, definitely. It is a big issue, and some of this is more art than science. But certainly explaining to patients that prioritizing sleep is important is the first place to start. So some people can't sleep more because of social pressures or because of young kids or multiple jobs. But there's others. I have lots of patients staying up late watching Netflix because they enjoy that and understanding that prioritizing sleep over Netflix can be somewhat of a quick fix in some people. Now, it's obviously hard to change human behavior, but that is one that is worth emphasizing. And if people understand that their diet isn't going to work, if they're burning the candle at both ends, then some of them will sleep adequately just to help with their diet and exercise strategy. The other thing to be aware of, Mary, in people with obesity is that obstructive sleep apnea is a very common disease. So we've estimated about a billion people worldwide with obstructive sleep apnea. That number numbers increasing, not decreasing over time, even with GLP1 receptor agonists and other progress in that area. So if you see people with obesity, be aware of obstructive sleep apnea. So snoring, excessive daytime sleepiness, hypertension, particularly refractory medications should prompt an evaluation for sleep apnea.

[B]

Your review talks also about an association of very prolonged sleep with obesity. Can you discuss that please?

[C]

Yeah, that's one of these ones that is easy to try to ignore, but it's there in many, many different cohorts that excessive sleep also has health consequences. We don't know why. We have a few papers on that. The very long sleepers tend to have increased risk of depression and certain inflammatory conditions. But we see these patients clinically. I think there's just something different about them. They're often quite socially isolated. They often don't have jobs or families or friends. People sleeping 12 hours are just very different from other individuals. And so I think there's non specific factors that come into play there. Makes me a bit nervous though, because we often run around saying, oh, you should sleep more and then on the backside there's this potential toxicity of excessive sleep. Although I think many of us believe there's confounding factors there or misreporting. But even when you objectively measure sleep duration, there's still this signal that excessive sleep can be problematic, perhaps as a marker of other diseases.

[B]

Yes, perhaps depression for one.

[C]

That is one factor. Yeah.

[B]

And then what do we know about treatments that improve both sleep and obesity?

[C]

Yeah. So treatments to improve sleep are often behavioral. A cognitive behavioral therapy for insomnia can be quite good for people that have insomnia and that involves prioritizing what we call sleep restriction, spending less time in bed and what's called stimulus control, where you avoid activities in bed other than intimacy and sleep. Scrolling Netflix and doing these things in bed should be avoided if you want to prioritize sleep in terms of treating obesity. Certainly diet and exercise can be helpful, but as I often joke, if diet and exercise were highly effective, I would be skinnier. And so there are other agents now that are coming into play. So we were involved in the Tirzepatide studies the surmount OSA that got FDA approved in 2024 for the treatment of people with moderate to severe sleep apnea with obesity. And that can be quite helpful in terms of inducing about 18 to 20% weight loss with concomitant improvements in sleep apnea severity. Based on the apnea hypopnea index. We also pre specified a number of secondary outcomes controlled for multiple comparisons. We saw improvements in systolic blood pressure, the so called hypoxic burden, the sleep apnea specific hypoxic burden based on the magnitude and duration of desaturations. We saw improvements in high sensitivity C reactive protein, which we know is a strong cardiovascular risk marker. We saw improvements in patient reported outcomes as well. Body weight as I said, improved 18 to 20%. So if you start out 200 pounds, 20% would be 40 pounds. So quite a game changer to go from 200 pounds to 160 pounds. And so that's become a fairly common intervention in the sleep clinics as well. So tirzepatide is a GLP one with gip, that's glucagon like peptide with gastric inhibitory peptide, also known as glucose dependent insulotropic polypeptide. And so that's a dual agonist that seems to work quite well for these individuals.

[B]

And Medicare will cover tirzepatide for treating sleep apnea. Correct. But can you clarify what the FDA indication is mentioned? Obesity. But do people with overweight also qualify if they have sleep apnea?

[C]

So it's a little tricky with different insurances, have different policies here the FDA approval was initially for diabetes and then later for obesity, and then later for obesity in the context of sleep apnea. So people that had moderate to severe sleep apnea in people with obesity. The issue there is, it's a little tricky how you define obesity. The FDA didn't specify a weight cutoff in their approval. And so you could argue if Your BMI is 28, but you have severe sleep apnea, that you do have a consequence of excess body fat. And so you could argue that is obesity even it's not above the cutoff of 30, which is relatively arbitrary. And so the surmount OSA study that I was involved in, the minimum BMI to get in there was over 30 kilograms per meter squared. But there are patients getting it with lower BMIs. If you suggest that they have sleep apnea as a consequence of excess body

[B]

weight for people without sleep apnea, is there any high quality evidence that the GLP1 receptor agonists improve sleep quality or duration in those with overweight or obesity?

[C]

You know, not that I know of. Mary. We're just about to publish some data on the sleep architecture, the changes in sleep stages and this kind of thing with Tirzepatide. But the majority of what we're seeing are improvements in sleep apnea. So without sleep apnea, are there improvements just by losing weight? The answer is I don't know. I don't think that's a big effect when I see these patients clinically. But, you know, it's possible.

[B]

Is there any evidence that if you help people improve sleep, they will lose more weight? I guess you referred to the Annals of Internal Medicine trial.

[C]

Yeah, there are other papers on that as well. Mary. So Ezra Tselli, also in Chicago, did some work on this where she took habitual short sleepers and extended their sleep time. She had them sleep more rather than less. And that did help to facilitate weight loss in those individuals. And so it's not just these epidemiological associations, but they're actual interventional studies now saying that sleeping more can have health benefits.

[B]

This was really informative. Atul, are there any things you'd like to add that we did not cover today?

[C]

No, just a couple take home messages. If I may again reiterate that we consider diet, exercise and sleep the three pillars of health. If you ignore one, the other two will suffer. Number two is snoring. Some people think it's funny. It's not actually funny. It can be a marker of fairly important health consequences like sleep apnea. And so if you think you have a problem, go talk to your doctor. And if you think your patient has an issue, dig deeper. It's not one of those things to dismiss or ignore or make fun of. I've had patients get divorced over snoring because their spouses are in different beds. I've had other patients with severe sleep apnea who are amenable to treatment. Nasal cpap, continuous positive airway pressure is still first line treatment. And adjunctive therapies with GLP1 receptor agonists with GIP can be quite helpful to improve sleep apnea and overall cardiometabolic health.

[B]

I'm Mary McDermott and I've been speaking today with Atul Malhotra about his JAMA insights on the topic of obesity and sleep. You can find a link to the article in this episode's description. For more of our podcasts, please visit us @jama network audio.com you can subscribe and listen wherever you get your podcasts. This episode was produced by Shelley Steffens at the JAMA Network. Thanks for listening. This content is protected by copyright by the American Medical association with all rights reserved, including those for text and data mining, AI training, and similar technologies.