Dairy consumption is associated with improved odds of adequate sleep, no trouble sleeping, and less variable sleep in U.S. adults.
Key Findings
Results
High total dairy intake was associated with significantly lower odds of both short and long sleep duration compared to low intake.
High total dairy intake was associated with 16% lower odds of short sleep duration (<7 h/day) and 23% lower odds of long sleep duration (≥9 h/day)
Both associations showed significant trends (all P-trend ≤ 0.01)
Sleep duration categories were defined as <7, 7-9 (reference), and ≥9 h/day
Analysis was based on 23,480 men and women from the 2005-2020 National Health and Nutrition Examination Survey (NHANES)
Dairy intake was categorized as low, moderate, and high based on sex-specific tertiles, with mean total dairy intake of 1.76 (SD 1.34) cup-eq/day
Results
High total dairy intake was associated with lower odds of trouble sleeping compared to low intake.
OR for high vs. low dairy intake was 0.86 (95% CI: 0.75–1.00)
The trend was statistically significant (P-trend < 0.05)
Trouble sleeping was assessed via self-report questionnaire (yes/no)
High-fat dairy specifically was also associated with lower odds of trouble sleeping (P-trend < 0.03)
Results
Milk consumption was similarly associated with reduced odds of both short and long sleep duration.
Associations between milk subtype and sleep duration were statistically significant (all P-trend < 0.03)
This pattern mirrored findings for total dairy intake and sleep duration
Dairy subtypes examined included milk, high-fat dairy, and fermented dairy
Results
High total dairy intake was associated with a higher sleep regularity index based on objective accelerometer data.
Objective sleep measures were derived from accelerometer data in a subsample of n = 4,972 participants
The association between high vs. low total dairy intake and sleep regularity index was statistically significant (P-trend < 0.03)
Survey-weighted multivariate linear regression was used for objective sleep outcomes
Results
Fermented dairy intake was associated with less variable sleep midpoint and lower odds of poor sleep.
Fermented dairy was associated with less variable sleep midpoint and lower odds of poor sleep (all P-trend < 0.03)
These associations were observed using objective accelerometer-derived sleep measures in the subsample of n = 4,972
Fermented dairy was examined as a distinct subtype from total dairy, milk, and high-fat dairy
Methods
The study sample was nationally representative of U.S. adults and included both self-reported and objective sleep measures.
Total sample included 23,480 men and women with mean age 46.7 ± 17.3 years
Data were drawn from the 2005–2020 NHANES cycles
Dietary intake was estimated from two 24-hour dietary recalls
A subsample of 4,972 participants had accelerometer-derived objective sleep data
Survey-weighted multivariate logistic and linear regression models were used for self-reported and objective outcomes, respectively
What This Means
This research suggests that eating more dairy products is linked to better sleep patterns in American adults. Using data from over 23,000 people collected between 2005 and 2020, the study found that adults who consumed the most dairy were less likely to sleep too little (under 7 hours) or too much (9 or more hours) compared to those who consumed the least dairy. They were also less likely to report trouble sleeping. These findings held for total dairy as well as specific types, including milk and high-fat dairy products.
The study also used wrist-worn activity monitors to objectively measure sleep in a smaller group of about 5,000 people. Among these participants, higher total dairy intake was associated with more regular sleep schedules, and people who ate more fermented dairy (such as yogurt or cheese) had less variation in when they fell asleep and were less likely to be classified as poor sleepers. These objective findings add support to the self-reported results.
This research suggests that dairy consumption — particularly fermented dairy products — may be connected to healthier, more consistent sleep. However, the study was observational, meaning it cannot prove that eating dairy directly causes better sleep. The authors note that additional studies, including long-term and experimental designs, are needed to determine whether this relationship is causal and to understand the biological mechanisms that might explain it.
Guyonnet E, Andreeva V, St-Onge M. (2026). Total dairy consumption is associated with healthy sleep patterns in U.S. adults.. Journal of clinical sleep medicine : JCSM : official publication of the American Academy of Sleep Medicine. https://doi.org/10.1007/s44470-025-00014-2