A higher carbohydrate-to-fiber ratio in the diet may lead to a greater risk of short sleep duration in individuals with constipation.
Key Findings
Results
Higher carbohydrate-to-fiber ratios were associated with increased risk of short sleep duration in adults with constipation.
Compared to individuals with a carbohydrate-to-fiber ratio <12.84, those with ratios of 17.66–26.18 had OR = 2.02 (95% CI: 1.25–3.28, P = 0.009) for short sleep duration
Those with ratios >26.18 also had OR = 2.02 (95% CI: 1.13–3.62, P = 0.03) for short sleep duration
The reference group was individuals with normal sleep duration
Total sample included 947 participants with constipation from NHANES 2005–2010
Results
A nonlinear association was observed between carbohydrate-to-fiber ratio and short sleep duration in adults with constipation.
Restricted cubic splines (RCS) were used to model the dose-response relationship
The nonlinear pattern was specific to short sleep duration, not long sleep duration
Multivariable logistic regression and subgroup analyses were also employed to examine the association
Results
No association was found between carbohydrate-to-fiber ratio and long sleep duration in constipated individuals.
The analysis distinguished between short sleep duration and long sleep duration as separate outcomes
The results did not confirm an association between the carbohydrate-to-fiber ratio and long sleep duration
This directional asymmetry suggests the dietary quality indicator selectively relates to insufficient rather than excessive sleep
Methods
The study defined constipation using the Bristol Stool Form Scale (BSFS) and assessed dietary carbohydrate quality via the carbohydrate-to-fiber ratio from 24-hour dietary recall.
Constipation was defined according to the Bristol Stool Form Scale (BSFS)
The carbohydrate-to-fiber ratio was obtained through the first 24-h dietary recall questionnaire
Sleep duration was assessed through the Sleep Disorder Questionnaire
The carbohydrate-to-fiber ratio is described as 'a novel indicator for evaluating dietary carbohydrate quality that can more accurately reflect an individual's dietary quality'
Multicollinearity was quantified using the variance inflation factor
Methods
The study population consisted of 947 American adults with constipation drawn from NHANES data collected between 2005 and 2010.
Data source was the National Health and Nutrition Examination Survey (NHANES) conducted in the United States
Survey years covered were 2005 to 2010
Total included participants numbered 947
This was a cross-sectional study design, limiting causal inference
What This Means
This research suggests that among American adults who experience constipation, the quality of dietary carbohydrates — specifically the ratio of total carbohydrates to dietary fiber consumed — is linked to how long they sleep at night. People with constipation who ate diets with a higher carbohydrate-to-fiber ratio (meaning relatively more refined or low-fiber carbohydrates compared to fiber) were about twice as likely to report sleeping less than the normal recommended amount compared to those who ate diets with a lower, more fiber-rich carbohydrate profile. This relationship followed a nonlinear pattern, meaning the increased risk was particularly evident above certain threshold ratios.
Importantly, no such association was found for long sleep duration — the dietary carbohydrate quality measure only appeared relevant to the risk of sleeping too little, not too much. The study used data from nearly 1,000 adults with constipation participating in a large, nationally representative U.S. health survey, and the researchers accounted for multiple potential confounding factors in their analysis.
This research suggests there may be a connection between gut health, diet quality, and sleep in people who already experience digestive issues like constipation. Because this was a cross-sectional study (a snapshot in time rather than a follow-up over time), it cannot prove that a high carbohydrate-to-fiber diet directly causes short sleep — the relationship could run in other directions or be influenced by unmeasured factors. Still, the findings highlight the potential importance of fiber-rich carbohydrate choices for sleep health, particularly in individuals dealing with constipation.
Zhang J, Yao C, Zheng Y, Guo Q. (2026). Association between dietary carbohydrate-to-fiber ratio and sleep duration among American adults with constipation: A cross-sectional study.. Experimental gerontology. https://doi.org/10.1016/j.exger.2026.113066