Total daily energy expenditure has declined over the past three decades due to declining basal expenditure, not reduced activity expenditure.

Obesity is caused by a prolonged positive energy balance1,2. Whether reduced energy expenditure stemming from reduced activity levels contributes is debated3,4. Here we show that in both sexes, total energy expenditure (TEE) adjusted for body composition and age declined since the late 1980s, while adjusted activity energy expenditure increased over time. We use the International Atomic Energy Agency Doubly Labelled Water database on energy expenditure of adults in the United States and Europe (n = 4,799) to explore patterns in total (TEE: n = 4,799), basal (BEE: n = 1,432) and physical activity energy expenditure (n = 1,432) over time. In males, adjusted BEE decreased significantly, but in females this did not reach significance. A larger dataset of basal metabolic rate (equivalent to BEE) measurements of 9,912 adults across 163 studies spanning 100 years replicates the decline in BEE in both sexes. We conclude that increasing obesity in the United States/Europe has probably not been fuelled by reduced physical activity leading to lowered TEE. We identify here a decline in adjusted BEE as a previously unrecognized factor.

Variability in energy expenditure is much greater in males than females.

In mammals, trait variation is often reported to be greater among males than females. However, to date, mainly only morphological traits have been studied. Energy expenditure represents the metabolic costs of multiple physical, physiological, and behavioral traits. Energy expenditure could exhibit particularly high greater male variation through a cumulative effect if those traits mostly exhibit greater male variation, or a lack of greater male variation if many of them do not. Sex differences in energy expenditure variation have been little explored. We analyzed a large database on energy expenditure in adult humans (1494 males and 3108 females) to investigate whether humans have evolved sex differences in the degree of interindividual variation in energy expenditure. We found that, even when statistically comparing males and females of the same age, height, and body composition, there is much more variation in total, activity, and basal energy expenditure among males. However, with aging, variation in total energy expenditure decreases, and because this happens more rapidly in males, the magnitude of greater male variation, though still large, is attenuated in older age groups. Considerably greater male variation in both total and activity energy expenditure could be explained by greater male variation in levels of daily activity. The considerably greater male variation in basal energy expenditure is remarkable and may be explained, at least in part, by greater male variation in the size of energy-demanding organs. If energy expenditure is a trait that is of indirect interest to females when choosing a sexual partner, this would suggest that energy expenditure is under sexual selection. However, we present a novel energetics model demonstrating that it is also possible that females have been under stabilizing selection pressure for an intermediate basal energy expenditure to maximize energy available for reproduction.

Total energy expenditure is repeatable in adults but not associated with short-term changes in body composition.

Low total energy expenditure (TEE, MJ/d) has been a hypothesized risk factor for weight gain, but repeatability of TEE, a critical variable in longitudinal studies of energy balance, is understudied. We examine repeated doubly labeled water (DLW) measurements of TEE in 348 adults and 47 children from the IAEA DLW Database (mean ± SD time interval: 1.9 ± 2.9 y) to assess repeatability of TEE, and to examine if TEE adjusted for age, sex, fat-free mass, and fat mass is associated with changes in weight or body composition. Here, we report that repeatability of TEE is high for adults, but not children. Bivariate Bayesian mixed models show no among or within-individual correlation between body composition (fat mass or percentage) and unadjusted TEE in adults. For adults aged 20-60 y (N = 267; time interval: 7.4 ± 12.2 weeks), increases in adjusted TEE are associated with weight gain but not with changes in body composition; results are similar for subjects with intervals >4 weeks (N = 53; 29.1 ± 12.8 weeks). This suggests low TEE is not a risk factor for, and high TEE is not protective against, weight or body fat gain over the time intervals tested.

Physical activity and fat-free mass during growth and in later life.

BACKGROUND: Physical activity may be a way to increase and maintain fat-free mass (FFM) in later life, similar to the prevention of fractures by increasing peak bone mass. OBJECTIVES: A study is presented of the association between FFM and physical activity in relation to age. METHODS: In a cross-sectional study, FFM was analyzed in relation to physical activity in a large participant group as compiled in the International Atomic Energy Agency Doubly Labeled Water database. The database included 2000 participants, age 3-96 y, with measurements of total energy expenditure (TEE) and resting energy expenditure (REE) to allow calculation of physical activity level (PAL = TEE/REE), and calculation of FFM from isotope dilution. RESULTS: PAL was a main determinant of body composition at all ages. Models with age, fat mass (FM), and PAL explained 76% and 85% of the variation in FFM in females and males < 18 y old, and 32% and 47% of the variation in FFM in females and males ≥ 18 y old, respectively. In participants < 18 y old, mean FM-adjusted FFM was 1.7 kg (95% CI: 0.1, 3.2 kg) and 3.4 kg (95% CI: 1.0, 5.6 kg) higher in a very active participant with PAL = 2.0 than in a sedentary participant with PAL = 1.5, for females and males, respectively. At age 18 y, height and FM-adjusted FFM was 3.6 kg (95% CI: 2.8, 4.4 kg) and 4.4 kg (95% CI: 3.2, 5.7 kg) higher, and at age 80 y 0.7 kg (95% CI: -0.2, 1.7 kg) and 1.0 kg (95% CI: -0.1, 2.1 kg) higher, in a participant with PAL = 2.0 than in a participant with PAL = 1.5, for females and males, respectively. CONCLUSIONS: If these associations are causal, they suggest physical activity is a major determinant of body composition as reflected in peak FFM, and that a physically active lifestyle can only partly protect against loss of FFM in aging adults.

Beliefs of women of childbearing age on healthy sleep habits: a reasoned action approach elicitation study.

There is little information on the determinants of healthy sleep habits (HSH) among women of childbearing age (WOCBA). The objective was to identify WOCBA's beliefs on HSH based on the Reasoned Action Approach. Thirty WOCBA (18-41 years) were randomly assigned to answer questions regarding one of three HSH: avoiding screen use in bed; avoiding caffeine, alcohol and cigarettes before bedtime; and having a regular bedtime and wake up time even on weekends. A content analysis was performed independently by two experts to identify the most important beliefs using a 75% cumulative frequency of mention. Participants reported that adopting the HSH would improve sleep, avoid side effects, help them relax before bedtime and make them feel like they were missing out on things. Adopting the HSH was associated with feeling relaxed and satisfied, but also qualified as unpleasant and abnormal. WOCBA mentioned their parents, partner, siblings and children would approve/disapprove if they adopted the HSH and were the most/least likely to adopt them. Barriers were having activities in the evening and social situations. Facilitating factors were putting their electronic devices away from bed, having alternatives and a regular schedule. These results can guide the development of interventions promoting HSH among WOCBA.

Energy compensation and adiposity in humans.

Understanding the impacts of activity on energy balance is crucial. Increasing levels of activity may bring diminishing returns in energy expenditure because of compensatory responses in non-activity energy expenditures.1-3 This suggestion has profound implications for both the evolution of metabolism and human health. It implies that a long-term increase in activity does not directly translate into an increase in total energy expenditure (TEE) because other components of TEE may decrease in response-energy compensation. We used the largest dataset compiled on adult TEE and basal energy expenditure (BEE) (n = 1,754) of people living normal lives to find that energy compensation by a typical human averages 28% due to reduced BEE; this suggests that only 72% of the extra calories we burn from additional activity translates into extra calories burned that day. Moreover, the degree of energy compensation varied considerably between people of different body compositions. This association between compensation and adiposity could be due to among-individual differences in compensation: people who compensate more may be more likely to accumulate body fat. Alternatively, the process might occur within individuals: as we get fatter, our body might compensate more strongly for the calories burned during activity, making losing fat progressively more difficult. Determining the causality of the relationship between energy compensation and adiposity will be key to improving public health strategies regarding obesity.

Relationship of added sugars intakes with physiologic parameters in adults: an analysis of national health and nutrition examination survey 2001-2012.

INTRODUCTION: Consumption of added sugars (AS) has been associated with increased risk for liver disease and risk factors for cardiovascular disease. The objective of this study was to further understand the relationship of AS intake with liver enzymes and risk factors for cardiovascular disease in adults (n = 29,687) participating in the National Health and Nutrition Examination Survey (NHANES) 2001-2012. METHODS: Individual usual intake (IUI) of AS was estimated using the Markov Chain Monte Carlo ratio method using two days of 24-hour dietary recalls gathered using standardized protocols. Subjects were separated into six consumption groups: 0 to <5%, 5 to <10%, 10 to <15%, 15 to <20%, 20 to <25% and ≥25% of energy as added sugars. Linear and group trends were determined using regression analyses for liver enzymes, cardiovascular risk factors, weight parameters, glucose, metabolic syndrome, and C-reactive protein. Logistic regression calculated odds ratios for these biomarkers above established risk levels (p < 0.01). RESULTS: There was an inverse group trend association with AS IUI for lower body mass index (beta = -0.12 kg/m2 across AS intake groups); % overweight/obese or % obese also showed inverse group trend (-1.44, -0.77, % units across AS intake groups, respectively). Liver enzymes did not show a significant association with AS IUI. Mean plasma glucose levels (mg/dL) showed an inverse linear (beta = -0.13 mg/dL per AS intake); and group association with energy from AS IUI (beta = -0.71mg/d L across AS intake groups). There was no association of AS intake with the risk of elevated uric acid levels; however, the odds of reduced uric acid levels was 17% lower with increasing intake of energy from AS IUI in group trend analysis only (0.83; 0.72-0.95 [99th CI]). CONCLUSION: Although it is sensible to consume AS in moderation, results suggested that higher intakes of AS were not consistently associated with physiologic parameters. Since the data were cross-sectional, they cannot be used to assess cause and effect. Thus, additional studies are warranted to confirm these findings with more rigorous study designs.

Nutrient intake, introduction of baby cereals and other complementary foods in the diets of infants and toddlers from birth to 23 months of age.

INTRODUCTION: Understanding which foods are introduced in the diet and when provides valuable information on complementary feeding. Fortified baby rice cereal is the most common first solid food given to infants, often followed by other baby cereals. The objective of this study was to examine food patterns among infants and toddlers consuming rice or non-rice baby cereals versus non-consumers. METHODS: NHANES 2001-2014 data were used to assess dietary intake, nutrient adequacy, and food specific patterns of infants and toddlers. Groups were: baby cereal non-consumers (n = 3,910), non-rice baby cereal consumers (n = 711), and rice baby cereal consumers (n = 966). Those consuming both non-rice cereal and rice cereal were included in the rice cereal group (n = 9, 48, 61, and 10 for those 0-3, 4-6, 7-11, and 12-23 mos, respectively). Least-square means ± SEs were determined for nutrient intake and food group consumption by using covariate controlled regression analyses (p < 0.01). RESULTS: Baby cereal consumer groups, compared to non-consumers, had higher intakes of carbohydrates, iron, calcium, magnesium, zinc, and vitamin E, with lower percentage having intakes below the Estimated Average Requirement for iron, calcium, and vitamin E. Infants 0-3 mos and 4-6 mos in both baby cereal consumption groups consumed other solid foods, including baby foods and beverages, sweetened beverages, coffee and tea, 100% juice, vegetables (excluding potatoes), fruit, sugars, milk and yogurt, and mixed dishes. The baby cereal consumers and non-consumers groups had intakes aligned with the "American diet". Baby cereal non-consumers had a significantly higher percentage of exclusively breast fed at ages 0-3 mos and a lower percentage formula fed. CONCLUSION: This study provides detailed information on the introduction of baby cereals which was associated with better nutrient intakes and other complementary foods and intakes of nutrients that require special attention during early life. Further, cow's milk products and solid foods were introduced prior to the American Academy of Pediatrics' age recommendations.

Food Sources of Shortfall Nutrients Among US Adolescents: National Health and Nutrition Examination Survey (NHANES) 2011-2014.

To identify food sources of shortfall nutrients consumed by adolescents (n = 3156), data from the National Health and Nutrition Examination Survey (NHANES) (2011-2014) were used. Some of the food groups commonly consumed by adolescents made a significant contribution to shortfall nutrient intakes in the diet. Many food sources that provided significant amounts of shortfall nutrients were from foods that also provided nutrients to limit. Awareness of nutrient intakes and food sources is essential to establish dietary guidance in a practical context. Efforts to continue monitoring the food sources of nutrients consumed by adolescents will be important to improve the current knowledge on this topic of research.

Breakfast Consumption versus Breakfast Skipping: The Effect on Nutrient Intake, Weight, and Cognition.

Breakfast has long been promoted as the most important meal of the day. However, the lack of standard definitions of breakfast, breakfast consumers, and breakfast skippers, and the lack of a description of how "important" the meal is, especially compared with other meals, has hampered the ability to confirm this long-held belief. This review discusses potential definitions of breakfast and breakfast skippers, and how these definitions can affect how researchers, nutrition educators, and policy makers interpret data and make recommendations. Overall, breakfast, especially meals including ready-to-eat cereal, contributes to overall nutrient intake and diet quality. However, the association of breakfast consumption and weight parameters or cognition in children is controversial. Finally, challenges, opportunities, and research gaps with breakfast studies are discussed. The question of whether breakfast is the most important meal of the day remains unanswered.

Individual Correlates of Sleep Among Childbearing Age Women in Canada.

Objective/Background: Women of childbearing age (WOCBA) may be at high risk for short or poor sleep. Yet few studies have focused on this population. The study objective was to identify individual correlates of sleep duration and quality among WOCBA. Participants: The sample consisted of 9,749 WOCBA aged 18-44 years from the Canadian Community Health Survey 2011-2014. Methods: All variables were self-reported. Sleep duration was dichotomized as insufficient (< 7 hr/night) or adequate (≥ 7 hr/night). A composite score of sleep quality was dichotomized as having sleeping problems none/little or some/most/all the time. Age, ethnicity, level of education, household income, mood disorders, parity, geographical location, fruit and vegetable (FV) intake, physical activity, smoking and alcohol consumption were tested as correlates of sleep duration or quality using hierarchical logistic regression. Results: Ethnicity, parity, geographical location and smoking were correlates of sleep duration; this model discriminated 56.9% of WOCBA. Ethnic minorities, WOCBA with many children, living in urban areas and smoking were associated with lower odds of having adequate sleep duration. Ethnicity, level of education, mood disorders, geographical location, FV intake, and alcohol consumption were correlates of sleep quality; this model discriminated 59.0% of WOCBA. Ethnic minorities, lower level of education, mood disorders, living in urban areas, low FV intake, and alcohol consumption were associated with lower odds of having quality sleep. Conclusions: Some WOCBA may be more at risk for short or poor sleep based on their demographics and health behaviors. This can be used to identify which WOCBA are most in need of sleep interventions.

Intergenerational Effects of Health Issues Among Women of Childbearing Age: a Review of the Recent Literature.

PURPOSE OF REVIEW: This review summarizes the latest scientific evidence, primarily from systematic reviews/meta-analyses and large cohort studies, on the impact of health issues among women of childbearing age and their effect on their offspring during pregnancy and from birth to adulthood. RECENT FINDINGS: Women of childbearing age with overweight/obesity, diabetes, and hypertension prior to pregnancy are at increased risk for adverse outcomes during pregnancy, such as excessive gestational weight gain, gestational diabetes mellitus, and hypertensive disorders of pregnancy. These adverse outcomes could complicate delivery and put their offspring at risk of developing overweight/obesity, diabetes, and hypertension (i.e., intergenerational transmission of health issues). Interventions should target women of childbearing age, especially those who wish to conceive, in order to possibly stop the transmission of women's health issues to the offspring and favor a healthy pregnancy from the start. This could be one of the best strategies to promote both maternal and child health.

Food Sources of Energy and Nutrients of Public Health Concern and Nutrients to Limit with a Focus on Milk and other Dairy Foods in Children 2 to 18 Years of Age: National Health and Nutrition Examination Survey, 2011⁻2014.

Many children are not meeting current nutrient recommendations. The objective of this study was to determine the food sources of energy, nutrients of public health concern, and nutrients to limit with a focus on dairy foods. Twenty-four-hour dietary recall data from children 2⁻5 (n = 1511), 6⁻11 (n = 2193), and 12⁻18 years (n = 2172) participating in NHANES 2011⁻2014 were analyzed. Energy, fiber, calcium, potassium, vitamin D, added sugars, saturated fatty acids (SFA), and sodium intakes were sample-weighted and ranked on percentage contribution to the diet using specific food group intake and disaggregated data for dairy foods. For children 2⁻5, 6⁻11, and 12⁻18 years, milk, sweet bakery products, and sweetened beverages, respectively were the top food sources of energy, respectively. For calcium, potassium, and vitamin D, milk was the top ranked food source in all age groups. For children 2⁻5, 6⁻11, and 12⁻18 years, milk, sweet bakery products, and pizza, respectively were the top three ranked food sources of SFA; and sugar sweetened beverages and sweet bakery products were to top two food group sources of added sugars. Cured meats/poultry, pizza, and pizza, respectively, were the top ranked food sources of sodium for the three age groups. Identification of food sources of these nutrients can help health professionals implement appropriate dietary recommendations and plan age-appropriate interventions.

Association between sleep and overweight/obesity among women of childbearing age in Canada.

OBJECTIVES: Tests of the relationship between sleep and overweight/obesity (OW/OB) among women have been inconsistent. Few studies reporting such associations have focused on women of childbearing age. This paper investigates this association among Canadian women of childbearing age. METHODS: Data were from the Canadian Community Health Survey 2011-2014. The sample consisted of women aged 18-44 years. All variables were self-reported. Sleep duration was dichotomized as insufficient (< 7 h/night) or adequate (≥ 7 h/night). A composite score of sleep quality was used and dichotomized as poor none/little of the time or some/most/all of the time. Height and weight were used to calculate body mass index. Associations between sleep and OW/OB were assessed using logistic regression analyses with survey weights. Three models were computed for sleep duration/quality: model without covariates, model adjusted for demographics (age, ethnicity, level of education, household income, marital status, employment, parity, region, and season), and model adjusted for demographics and variables associated with OW/OB (mood disorder, fruit and vegetable intake, physical activity, smoking, and alcohol). RESULTS: Total sample consisted of 9749 women of childbearing age. Thirty-eight percent had insufficient sleep duration. Sleep duration was significantly associated with OW/OB in the model with no covariates and discriminated 52.8% of women of childbearing age, but this association was no longer significant in the models adjusted for covariates. Sleep quality was not significantly linked to OW/OB in any of the models. CONCLUSION: Targeting sleep alone would likely not contribute to lower risk of OW/OB among Canadian women of childbearing age. Additional studies, especially longitudinal ones, are needed to confirm these findings.

Associations Among Sleep, Body Mass Index, Waist Circumference, and Risk of Type 2 Diabetes Among U.S. Childbearing-Age Women: National Health and Nutrition Examination Survey.

BACKGROUND: Women of childbearing age (18-44 years) present an important group for understanding sleep, but few studies have focused on this population. No study has investigated the associations among sleep, overweight/obesity, and risk of type 2 diabetes among childbearing-age women in the National Health and Nutrition Examination Survey (NHANES). METHODS: Data were from NHANES, 2005-2008. The study population consisted of 18-44 year old women. Pregnant women and those diagnosed with sleep disorders were excluded. Sleep duration and quality were self-reported. Body mass index (BMI), waist circumference (WC) measurements, and a 2-hour 75 g oral glucose tolerance test (OGTT) were performed by trained NHANES staff. An unadjusted linear regression analysis; a second adjusted for demographics only (partially adjusted model); and a third adjusted for demographics and variables associated with overweight/obesity and diabetes (fully adjusted model) were computed to assess associations among sleep duration/quality and BMI, WC, and 2-hour OGTT. RESULTS: Total sample consisted of 2388 childbearing-age women. Only sleep duration was significantly associated with BMI and WC in the unadjusted and partially adjusted models, but was no longer significant in the fully adjusted model. Neither sleep duration nor quality was significantly associated with 2-hour OGTT in any of the models. CONCLUSIONS: Targeting sleep duration and sleep quality alone would not likely contribute to significantly lower BMI, WC, or risk of type 2 diabetes in US childbearing-age women. Additional studies, especially longitudinal ones using objective measures of sleep, are needed to confirm these findings.

Mommio's Recipe Box: Assessment of the Cooking Habits of Mothers of Preschoolers and Their Perceptions of Recipes for a Video Game.

BACKGROUND: Vegetables are an important part of a healthy diet because they help prevent several chronic diseases. Mothers of preschoolers reported difficulty getting their young children to eat vegetables, and many did not know how to cook child-pleasing recipes. OBJECTIVE: The cooking habits of mothers of preschoolers, their perceptions of recipes designed for their children, and the involvement of their children in food preparation were assessed to inform a food parenting video game called Mommio. METHODS: A cross-sectional survey design was used. Eligibility criteria included mothers of 3- to 5-year-old children who reported difficulty getting their children to eat vegetables. Participants completed a demographic questionnaire with questions about their food preparation practices. They were asked to select up to 4 of the 10 provided recipes they wanted to try and to prepare and report back on their experiences. RESULTS: Most (46) of the 50 recipes included in Mommio's in-game recipe box were evaluated at least once and some up to 5 times with a total of 85 evaluations. This well-educated, mostly employed, sample of 27 mothers of preschoolers preferred simple, quick recipes. They ate primarily at home, made dinners from scratch, and indicated that the 46 recipes were generally simple, quick, and easy to prepare. Involvement in preparation enhanced their child's acceptance of the food. Prior food and preparation preferences influenced the children's acceptance of the dish at the ensuing meal. CONCLUSIONS: The high rate of home recipe preparation indicated that including a recipe selection and preparation component in a food parenting video game could be attractive and may enhance effectiveness. Mothers reported that the recipes provided were generally easy to prepare, tasted good, and the instructions were easy to understand, suggesting they could be helpful to the mothers when playing a vegetable parenting game. Some mothers reported that involving their children in recipe preparation influenced their children's willingness to eat the vegetables. The highest rated recipes are being included in the game, and mothers will be encouraged to involve their children in recipe preparation.

Flavored Milk Consumers Drank More Milk and Had a Higher Prevalence of Meeting Calcium Recommendation Than Nonconsumers.

BACKGROUND: Some schools are removing flavored milk because of the perception that it negatively impacts children's overall diet. This study assessed the contribution of flavored milk to their diets. METHODS: Individual usual intakes (IUI) were calculated from 24-hour dietary recalls of children 2-18 years (N = 20,329) participating in National Health and Nutrition Examination Survey (NHANES) 2001-2012. IUI of >0.25 cup equivalent of flavored dairy milk defined consumers (N = 3564; 56% boys). Covariate-adjusted regression analyses using appropriate sample weights were calculated. Estimated Average Requirements (EAR) and Adequate Intakes (AI) determined the relation to dietary recommendations. Consumers were compared to nonconsumers (p ≤ .001). RESULTS: Flavored milk consumers consumed more milk. Consumers aged 2-3 years had higher mean added sugars intakes. Consumers aged between 2-3 and 9-13 years had a higher saturated fat (SFA) intake. Consumers aged 14-18 years had higher percent energy from SFA. Consumers had a lower mean percentage of children meeting AI for fiber and a higher percentage meeting the EAR for calcium. Consumers aged 4-8 and 9-13 years had a higher mean percentage of children meeting the EAR for magnesium. CONCLUSIONS: Consumption of flavored milk has the potential to increase milk consumption and reduce the percentage of children below the EAR for calcium; the percentage meeting AI for fiber was lower.

Association Between Sleep Duration and Body Mass Index Among US Low-Income Preschoolers.

OBJECTIVE: To verify whether sleep duration was related to body mass index z scores (zBMI) and whether bedtimes or ethnicity was a moderator of the sleep duration-zBMI association among preschoolers from low-income families. METHODS: Two hundred twenty-eight African American and Hispanic parents and their preschoolers were recruited from Head Start Centers. Parents reported their preschoolers' sleep duration and bedtimes (using the Children's Sleep Habits Questionnaire) and their television watching. Food intake was measured using multiple days of digital photography to estimate energy intake at dinner. The Parenting Stress Index and the Center for Epidemiologic Studies Depression Scale were used to measure stress and depression. Parents' and preschoolers' height and weight were measured by trained staff. RESULTS: Longer sleep duration was significantly associated with lower zBMI when controlling for demographics, bedtimes, energy intake at dinner, and television watching, but not when also controlling for parents' demographics, BMI, stress, and depression. Preschoolers' sleep duration-zBMI association was not moderated by bedtimes or ethnicity. CONCLUSIONS: Longer sleep duration was associated with lower zBMI among low-income preschoolers when controlling for preschoolers' characteristics, but this was no longer the case when also controlling for parents' characteristics. Additional studies are needed on the moderators of the sleep duration-zBMI association among low-income preschoolers.

Individual, social and environmental determinants of sleep among women: protocol for a systematic review and meta-analysis.

INTRODUCTION: Sleep is important to promote optimal health and avoid negative health outcomes. Short-duration and low-quality sleep may be more common and more detrimental among women compared with men. Identifying the determinants of behaviour is one of the first steps in designing effective interventions. To our knowledge, no systematic review has identified the individual, social and environmental determinants of sleep among adult women. METHODS AND ANALYSIS: Studies reporting data on adult women from 18 to 64 years of age will be included. On the basis of ecological models of health behaviour and sleep, the types of determinants that will be included in the review are individual (eg, demographic, psychological and behavioural), social (eg, family) and environmental (eg, physical environment and policies) determinants. Observational (cross-sectional and longitudinal) and experimental studies will be included. MEDLINE/PubMed, PsycINFO, CINAHL, EMBASE and Proquest Dissertations and Theses will be investigated. Data will be extracted independently by two reviewers using a standardised data extraction form. The quality of observational studies will be assessed using the National Institute of Health Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies and the quality of experimental studies will be assessed using the Effective Public Health Practice Project Quality Assessment Tool for Quantitative Study. If there is a sufficient number of studies reporting data on a similar determinant among a similar population (k>5), a meta-analysis of the results will be performed with a random-effects model. If between-study heterogeneity is high (I2 ≥75%), it will be investigated through sensitivity analyses and meta-regression. ETHICS AND DISSEMINATION: Formal ethical approval is not required as no primary data will be collected. The results will be published in a peer-reviewed journal. This review will provide valuable information to those interested in developing empirically based sleep interventions among women. PROSPERO REGISTRATION NUMBER: CRD42017056894.