What Sleep Schedule and Food Habits Have to Do with Anxiety

Short nights, late coffee, eating at night and a diet heavy in ultra-processed food are all tied to higher anxiety. What the research shows, how strong it is, and where it stops.

By Teona Abuladze · 6 min read

In 2019, eighteen young adults at UC Berkeley spent a night awake in a sleep lab. The next morning they lay in an MRI scanner and watched emotionally stirring video clips. Compared with a morning after a full night’s sleep, their anxiety rose by up to 30 percent. Half of them crossed the level clinicians use to describe an anxiety disorder.

The day before, none of them had been anxious in any clinical sense.

The study, led by Eti Ben Simon in Matthew Walker’s lab, is one of the cleanest demonstrations of something many women know from lying awake at 3 a.m. Sleep and anxiety are wired together. Food and anxiety are connected too, more loosely. The evidence for the two is not equally strong, and the difference matters if you are deciding what to change.

Why this lands harder on women

According to the National Institute of Mental Health, 23.4 percent of American women had an anxiety disorder in the past year, against 14.3 percent of men. Women are also estimated to be about 40 percent more likely than men to have insomnia, according to University of Miami Health.

Each condition makes the other worse, and women carry more of both.

What one bad night does

In the Berkeley scans, the sleepless brain showed weaker activity in the medial prefrontal cortex, the region that helps keep emotions in check, while deeper emotional regions ran hot. Walker compared it to pressing the accelerator with too little brake.

The more hopeful finding came after the next night. People who got more deep, slow-wave sleep woke up less anxious. The team repeated the result with another 30 people, then tracked 280 people online for four days. Even small nightly changes in sleep predicted how anxious they felt the following day.

One sleepless night raised anxiety by up to 30 percent. A night with more deep sleep brought it down.

You don’t need an all-nighter to feel it. In 2023 the journal Psychological Bulletin published a meta-analysis of 154 experiments with more than 5,700 participants, spanning five decades. Total sleep deprivation, short sleep and broken sleep all raised anxiety symptoms and flattened positive mood. Lead author Cara Palmer of Montana State University said the effects appeared even after staying up an hour or two later than usual.

The authors flag a limit themselves: the average participant was 23 years old. We know much less about a woman of 45 in perimenopause, or 60.

Insomnia often comes first

The usual assumption is that anxiety keeps you awake. It does. The reverse is also true.

A 2019 meta-analysis in Sleep Medicine Reviews pooled long-term studies that followed people for years. Those who had insomnia at the start were about three times as likely to develop an anxiety disorder later.

Treating sleep seems to help anxiety. In the OASIS trial, Oxford researchers gave 3,755 students at 26 UK universities either a digital programme of cognitive behavioural therapy for insomnia (CBT-I) or usual care. After ten weeks the sleep group slept better, and their anxiety scores were lower as well. A later analysis of people with insomnia and significant anxiety estimated that 84 percent of the drop in anxiety ran through the improvement in sleep. One caution: several authors of that analysis have financial ties to Big Health, the company behind the app used, Sleepio.

People with insomnia were about three times as likely to develop an anxiety disorder later on.

Food: what is solid and what isn’t

Here the ground gets softer.

The biggest number comes from a 2024 umbrella review in The BMJ, which brought together meta-analyses covering almost 10 million people. A diet high in ultra-processed food (packaged snacks, sugary cereals, soft drinks, ready meals) was linked to a 48 to 53 percent higher risk of anxiety and common mental disorders. The authors rated that evidence “convincing.”

They were also clear that these are observational studies. Women who eat a lot of ultra-processed food are often poorer, more stretched for time, more stressed and shorter on sleep. The research can’t fully pull those apart from the food itself.

When researchers actually change what people eat, the anxiety results are weaker. A 2019 meta-analysis of randomised trials, led by Joseph Firth, found that improving diet reduced symptoms of depression but had no clear overall effect on anxiety. One detail stands out. In trials with only women, the diet changes showed significantly greater benefit for both depression and anxiety. Firth said the team did not yet know why.

So, for anxiety: a consistent pattern, a plausible biology, and no proven dietary treatment yet.

When you eat

At Brigham and Women’s Hospital in Boston, Frank Scheer and Sarah Chellappa kept 19 volunteers in a lab for two weeks and simulated night shifts. One group ate both day and night, the way many night workers do. The other ate only during the day.

During the simulated night shift, the round-the-clock group’s depression-like mood rose 26 percent and their anxiety-like mood 16 percent. The daytime-only group showed no rise.

It is a small study, 12 men and 7 women, and Chellappa has said the causal role of meal timing in mental health still has to be tested. It is still worth knowing for nurses, care workers, warehouse staff and anyone else whose shift runs through the night. Shift workers already carry a 25 to 40 percent higher risk of depression and anxiety.

Coffee and wine

Caffeine touches both sides of this story.

Directly, at high doses. A 2022 meta-analysis of caffeine challenge studies found that after 400 to 750 mg of caffeine, about half of people with panic disorder had a panic attack, compared with roughly 2 percent of healthy volunteers. A 2024 meta-analysis in people without psychiatric disorders found caffeine raised anxiety, most sharply above 400 mg.

And through sleep. In a 2013 study at Henry Ford Hospital in Detroit, 400 mg of caffeine (the authors put it at two to three cups of coffee) taken six hours before bed cut measured sleep by more than an hour. The participants didn’t notice they had lost it.

Caffeine taken six hours before bed cut sleep by more than an hour, and the sleepers had no idea.

Alcohol works in the opposite direction. It helps you fall asleep and deepens the first half of the night. A 2013 review of sleep-lab studies in Alcoholism: Clinical and Experimental Research found that sleep in the second half became more broken, and that two or more drinks reduced REM sleep, the stage most tied to processing emotion. Waking at 4 a.m. with a pounding heart after a dinner with wine has a physical explanation.

What the evidence supports

If sleep is the problem, treat it directly. CBT-I is the recommended first treatment for chronic insomnia and is available in digital form; a doctor or therapist can point you to it. Ben Simon’s own advice was to protect both how long and how regularly you sleep.

If you have panic attacks, caffeine is the most clearly documented dietary trigger. Moving it earlier in the day also protects sleep.

If you work nights, there is early, promising evidence for keeping meals to daytime hours where the job allows it.

Eating more whole food and less ultra-processed food is unlikely to hurt, and in trials of women it showed some benefit. On its own, it is not a treatment for an anxiety disorder.

Where this stops

Sleep and food are not the cause of most anxiety disorders, and better habits don’t cure them. Anxiety disorders respond to therapy, and for some women to medication, and many need both.

There is also a kind of sleeplessness no programme fixes. A woman lying awake because the rent is late, or because someone at home is not safe, has a real problem in front of her, and her anxiety is responding to it.

Teona Abuladze is the founder and editor of Shansi Magazine.

If anxiety is getting in the way of your days, a doctor or licensed therapist can help. In the US, you can also call or text 988 to reach the Suicide & Crisis Lifeline, which supports anyone in emotional distress.

Sources: UC Berkeley release on Ben Simon et al., “Overanxious and underslept,” Nature Human Behaviour, 2019 — https://www.eurekalert.org/news-releases/862776 ; GEN on the same study (50% above clinical threshold) — https://genengnews.com/news/overstressed-and-underslept-study-shows-how-deep-sleep-can-reset-anxious-brain ; NIMH, any anxiety disorder, via The Recovery Village — https://www.therecoveryvillage.com/mental-health/anxiety/anxiety-disorder-statistics/ ; University of Miami Health, behavioral health concerns among women — https://www.umiamihealth.org/treatments-and-services/uhealth-comprehensive-women’s-health-alliance/women’s-services/behavioral-health/common-behavioral-health-concerns-among-women-in-the-us ; APA release on Palmer et al., Psychological Bulletin, 2023 — https://www.apa.org/news/press/releases/2023/12/sleep-deprivation-anxious ; Newswise on the same — https://www.newswise.com/articles/sleep-deprivation-makes-us-less-happy-more-anxious ; Hertenstein et al., Sleep Medicine Reviews, 2019 — https://iris.unimarconi.it/handle/20.500.14241/736 ; Freeman et al., OASIS, Lancet Psychiatry, 2017 — https://nottingham-repository.worktribe.com/output/1221769 ; Henry et al., Journal of Affective Disorders, 2023 (84% mediation; conflicts of interest) — https://searchworks.jioinstitute.edu.in/articles/cmedm__37390923 ; BMJ Group release on Lane et al., umbrella review of ultra-processed food, 2024 — https://bmjgroup.com/consistent-evidence-links-ultra-processed-food-to-over-30-damaging-health-outcomes/ ; University of Manchester on Firth et al., Psychosomatic Medicine, 2019 — https://www.manchester.ac.uk/about/news/healthy-diet-can-ease-symptoms-of-depression/ ; Healio on Firth et al. — https://www.healio.com/psychiatry/depression/news/online/%7B4999cdd8-751f-4868-ae31-db0e983930c1%7D/healthy-diet-can-reduce-depressive-symptoms ; Brigham and Women’s Hospital release on Qian et al., PNAS, 2022 — https://www.eurekalert.org/news-releases/964188 ; ScienceAlert on the same — https://www.sciencealert.com/the-time-of-day-you-eat-could-make-a-difference-to-your-mental-health ; Klevebrant & Frick, General Hospital Psychiatry, 2022 — https://pubmed.ncbi.nlm.nih.gov/34871964/ ; Liu et al., Frontiers in Psychology, 2024 — https://pmc.ncbi.nlm.nih.gov/articles/PMC10867825/ ; AASM release on Drake et al., Journal of Clinical Sleep Medicine, 2013 — https://aasm.org/late-afternoon-and-early-evening-caffeine-can-disrupt-sleep-at-night/ ; Partnership to End Addiction on alcohol and second-half sleep disruption, 2013 — https://drugfree.org/?p=26603