How Is Sleep Linked With Obesity in Infants, Young Children?

Presenters at SLEEP 2023 in Indianapolis, Indiana, discussed 2 studies about the impact of sleep on obesity in infants and young children. One study linked circadian rest-activity rhythm (CRAR) development with obesity in early infancy. Another study showed that poor sleep in young children can increase their likelihood to eat without internal cues, such as emotional eating, which could lead to obesity.

Circadian Rhythms and BMI

Megan E. Petrov, PhD, an associate professor in the Edson College of Nursing and Health Innovation at Arizona State University, presented her research on how circadian rhythms could affect the weight gain of young infants. Past studies have revealed an association between CRAR and a higher body mass index (BMI) in both older children and adults.

Circadian rhythms, according to Petrov, emerge after birth. “Typically [it] comes about 4 to 5 weeks after birth with some variability. And that rhythm really begins to match with a 24-hour period and increase in strength in the subsequent weeks, particularly between the 6th and 12th week,” she said.

Petrov said that the research that she and her team did investigated the association between CRAR when the child was 8 weeks old and the growth rate from birth to 3 months. The researchers hypothesized that infants with better circadian rhythmicity will have greater change in weight-for-age (WAZ) and weight-for-length z-score (WLZ).

The team is conducting the Snuggle Bug/Acurrucadito Study, an ongoing longitudinal observational study looking at sleep-wake patterns, the gut microbiome, and feeding patterns of mothers and babies and the impact on early weight gain.

Pregnant participants are eligible to be included if they are 18 to 40 years old, with fetuses 37 weeks or more, and with had no pre-existing conditions that can affect the growth of offspring.

Children are followed until the age of 1 year old and they wear an ankle actigraph for 5 days. Data collected include mesor (mean activity count), acrophase (peak activity), and amplitude (difference between mesor and peak activity).

The mean (SD) age of the mothers was 32.8 (4.7) years and the mean gestational age for the fetuses was –3.1 (9.1) days before due date; 56.1% of infants were female and 17% were Hispanic or Latino. There were a total of 57 participants overall.

The mean mesor in the infants was 114.3 (13.7) at 8 weeks and acrophase was 14.25 (1.35).

“We find that lower, mesor activity count predicted greater change in [WLZ] score,” said Petrov. “So another way of saying this is each 1 SD increase in mesor was associated with a reduction in weight for WLZ score of 0.23 after adjusting for birth weight for age and weight.”

The researchers also found that lower amplitude was associated with a greater change in WLZ. Each SD increase in amplitude was associated with a reduction in WLZ score from birth to 3 months at 0.31. Goodness of fit score, which is correlated with amplitude, also had a similar result.

Petrov acknowledged that the study did have some limitations, given the small sample size, the maturation of rhythm not being examined, long-term outcomes not being studied, and sleep quantity and quality not being accounted for at 8 weeks of age.

“But what we find so far is that less robust risk rhythmicity, achieved at 8 weeks of age, is linked to a higher rate of weight gain in early infancy, from birth to 3 months,” she concluded.

Sleep Duration and Appetite

Emily E. Hohman, PhD, an assistant research professor in the Center for Childhood Obesity Research at Penn State University, also presented data on how sleep patterns could be linked to obesity in young children, with her study focusing on children aged 6 years.

Hohman noted that obesity is a significant public health problem in the United States, with 1 in 3 children overweight or obese before their fifth birthday. Childhood obesity has previouslybeen linked to short sleep and irregularity of sleep.

Young children with short or poor sleep have greater food responsiveness, greater emotional overeating, and eat more in the absence of hunger.

Hohman and her team looked into whether obesogenic appetitive traits were linked to short sleep duration, later sleep timing, poor sleep quality, irregular sleep duration, irregular sleep timing, and irregular sleep quality.

The Intervention Nurses Start Infants Growing on Healthy Trajectories (INSIGHT) study is an ongoing prospective, randomized, controlled trial at Penn State evaluating the efficacy of a responsive parenting (RP) intervention designed to prevent rapid infant weight gain and childhood obesity among first-born infants.


The study, funded by the National Institutes of Health, includes 279 duos of mothers and infants. Includion criteria includes singleton, term newborns of greater than or equal to 37 weeks of gestation with a birthweight of 2500 grams or greater, and primiparous mothers aged 20 years and older.

Participants are primarily non-Hispanic white and married, with 72% having an income of greater than or equal to $50,000 per year.

All children wore a Spectrum Actiwatch Plus on their non-dominant wrist for 7 days and children with at least 3 days of valid wear were included in the analysis. Sleep duration, sleep onset time, sleep midpoint, sleep end time, and sleep maintenance efficiency were all evaluated. A child eating behavior questionnaire evaluated food responsiveness, enjoyment of food, desire to drink, emotional overeating, and satiety responsiveness.

“We found that there is 1 of the 5 traits that was related to mean sleep duration and that was desire to drink,” said Hohman. Greater mean sleep duration was found to be associated with a lower desire to drink.

“We also saw patterns where higher enjoyment of food and higher emotional eating with greater variability in sleep duration,” she said. Although the results weren’t significant, it did represent an overall pattern of variability in sleep duration affecting eating patterns.

Sleep duration variability also increased children’s food responsiveness, their desire to drink, their enjoyment of food, and their emotional overeating. Variability in sleep onset time and sleep midpoint were associated with a higher desire to drink as well. Lastly, variability in sleep maintenance efficiency increased enjoyment of food and decreased satiety responsiveness in children. A mean sleep maintenance efficiency increased satiety responsiveness.

“We really saw there was variability in the sleep health characteristics that predicted repetitive traits rather than the mean levels,” said Hohman. “While mean and variability predicted a repetitive trait, they did so, unsurprisingly, in opposite directions.”

Although this study had some limitations, such as the short duration of the study, Hohman concluded by saying that regularity of sleep could be just as important as average sleep health when it comes to the regulation of eating behavior. However, further research is needed to explore these mechanisms.