Table 2.

Summary of reviewed studies for sleep and growth

Study	Country	Design	Sleep variable	Method of sleep assessment	Dependent variables	Number of subjects	Control group	Sleep measured at age	Key findings
Fairley et al45	UK	Longitudinal association study	Sleep duration over 24 hours with categories: <11 hours, 11–12 hours, 12–13 hours, and >13 hours sleep per 24 hours	Parent report at 24 months of age	Primary outcome: BMI z-score Additional outcome: overweight at the age of 3 years	987	None	24 months	No association between child sleep duration and mean BMI or risk of overweight at the age of 3 years
Fisher et al47	UK	Longitudinal association study	Nighttime sleep duration with categories: <10 hours a night, 10–11 hours a night, 11–12 hours a night, 12–13 hours a night, and ≥13 hours a night	Modified items of the Brief Infant Sleep Questionnaire	Primary outcome: energy intake (g/day of fat, carbohydrate, and protein)	1303	None	16 months	Shorter nighttime sleep was associated with higher total energy intake. Children sleeping <10 hours consumed around 50 kcal/day more than those sleeping 11–12 hours a night No association between sleep and weight
					Additional outcomes: body weight
Gibson et al35	New Zealand	Cross-sectional association study	Daytime and nighttime sleep patterns and sleep efficiency	Actigraphy for 1 week, sleep log, and Brief Infant Sleep Questionnaire	Primary outcome: general cognitive development measured with the Ages and Stages Questionnaire and BMI Additional outcomes: motor development measured with Ages and Stages Questionnaire	52	None	1 year	Sleep measures were not correlated with infant BMI
Gillman et al41	USA	Longitudinal association study	Daytime and nighttime sleep patterns	Mothers’ report of the number of hours their children slept in a 24-hour period	Primary outcome: overweight Additional outcomes: weight and height, and BMI z-scores	914 (for sleep analyses)	Children who sleep <12 hours/day versus those who sleep at least 12 hours/day	6 months and 1 year	The predicted probability of overweight in childhood varied from 6% to 29%, depending on the levels of four risk factors, which included daily sleep pattern in infancy
Lampl and Johnson55	USA	Longitudinal association study	Daytime and nighttime sleep pattern and sleep efficacy	Parental diaries; infant sleep patterns were quantified by approximate entropy	Primary outcome: saltatory length growth	23	Each subject was his/her own control for cluster analyses	Over 4–17 months	Saltatory length growth was associated with increased total daily sleep hours and number of sleep bouts, with breast-feeding, infant sex, and age as covariates
					Additional outcomes: weight and weight gain, adiposity, and changes in subcutaneous skinfolds				Peaks in individual sleep of 4.5 or more hours and/or three more naps per day were concordant with saltatory length growth, with a time lag of 0–4 days Increased sleep bout duration predicted weight and abdominal skinfold accrual contingent on length growth, and truncal adiposity independent of growth
Paul et al48	USA	Randomized controlled trial	Daytime and nighttime sleep patterns	Maternal 96-hour diary of infant sleep	Primary outcomes: weight-for-length percentiles	160 included and 110 completed	Four groups: “Soothe/sleep”, “Introduction of solids”, both interventions, and no intervention	3, 4, 8, 16, 24, 36, and 48 weeks	At 1 year, infants who received both interventions had lower weight-for-length percentiles than the other groups
					Additional outcomes: weight gain score, infant behavior, and feeding				The interventions influenced sleep duration and feeding frequency
Taveras et al46	USA	Longitudinal Association study	24-Hour sleep cycle and sleep curtailment score	Mothers’ report of sleep duration in 24-hour period	Primary outcome: BMI z-score	1046	Children with low versus high sleep scores	6 months, and 1, 2, 3, 4, 5, 6, and 7 years	Children with less sleep had higher BMI z-scores than children with more sleep
					Additional outcomes: dual X-ray absorptiometry, total and trunk fat mass index, waist and hip circumference, and subscapular and triceps skinfold thicknesses				Higher total and trunk fat mass index and waist and hip circumferences and higher odds of obesity in children with less versus more sleep
Taveras et al40	USA	Longitudinal association study	Daytime and nighttime sleep patterns	Mothers’ report of the number of hours their children slept in a 24-hour period	Primary outcomes: BMI z-score, skinfold thickness, and overweight at the age of 3 years	915	None	6 months, 1 and 2 years	Infant sleep of <12 hours/day in the first 2 years of life was associated with a higher BMI, skinfold thickness, and an increased risk for overweight at the age of 3 years Sex differences and breast-feeding at night were confounding factors
Tikotzky et al43	Israel	Cross-sectional association study	Daytime and nighttime sleep patterns	Actigraphy for four consecutive night and Brief Infant Sleep Questionnaire	Primary outcomes: weight, length, and weight-to-length ratio	96	None	6 months	Sleep percentage by actigraphy and reported sleep duration were both negatively correlated with weight-to-length ratio
Wake et al50	Australia	Follow-up of a randomized controlled trial	Parent-reported sleep problems	Parent report	BMI z-score, percentage overweight, and waist circumference	328 included and 193 analyzed	Two groups: behavioural sleep intervention at 8–10 months versus control	4, 7, and 10 months, and 1, 2, and 6 years	No effect on growth outcomes at the age of 6 years
Worobey et al44	USA	Longitudinal association study	Daytime and nighttime sleep patterns	Actigraphy and maternal 24-hour diary of infant sleep	Primary outcome: weight-for-length percentiles by gender at 3 and 6 months	154	None	3 and 6 months	Sleep did not predict weight gain from 3 to 6 months
Zhou et al42	Singapore	Longitudinal association study	Daytime and nighttime sleep patterns	Brief Infant Sleep Questionnaire	Primary outcomes: BMI and body length	899	None	3, 6, 9, 12, 18, and 24 months	Sleep duration was significantly associated with body length in the overall cohort Only in Malay children, shorter sleep was associated with a higher BMI Infant sleep of <12 hours/day at 3 months of age was associated with a higher BMI and shorter body length

Abbreviation: BMI, body mass index.