The DREAM study

Background

One in three New Zealand children are heavier than desired for their health. When we think of what affects our body weight, we tend to go first to diet and physical activity. However, it is now clear that inadequate sleep is also a strong independent risk factor for obesity in children, however the mechanisms driving this relationship needed further investigation.

Research design

The DREAM study was a randomised cross-over trial that investigated whether small changes in the amount of sleep children have, affects:

• the types of foods they eat;
• how much food they consume (total energy);
• how much physical activity they do;
• how much screen use they engage in;
• their wellbeing and quality of life

The researchers followed 105 children for several weeks, including one week to understand normal sleeping behaviour and two weeks of sleep intervention. During the sleep intervention there was one week that the children were asked to go to bed an hour earlier than normal, and one week that the children were asked to go to bed later than usual.

Some careful measurements were done to help us understand whether being tired really does affect what children eat and how active they are, and the other health related outcomes.

Findings from the DREAM study

The DREAM study researchers found that getting less sleep resulted in children consuming more energy, especially from poorer food choices and highly processed foods. Interestingly, there was little change in the physical activity patterns of the children.

These results help us to understand why children who sleep less are more likely to be overweight.

What's next?

The next step is to explore what resources are needed to improve sleep in children. Discovering effective interventions that focus on improving sleep in children may play an important role in the prevention and treatment of childhood obesity.

Researchers on the DREAM study

The DREAM study in the media

• Study links sleep and eating habits, Otago Daily Times, 20 March 2022
• Watch a short video about the DREAM study, for the Science Media Centre video competition
• Read a Sciblogs article about the DREAM study, August 2020
• It's World Obesity Day - and sleep is on the menu! 4 March, 2020

Publications

Jackson RF, Meredith-Jones KA, Haszard JJ, Galland BC, Morrison S, Jaques M, & Taylor RW. (2026). The influence of different processing rules on wearable camera data estimates of habitual screen time in children. Journal of Activity, Sedentary and Sleep Behaviors. https://doi.org/10.1186/s44167-026-00095-1

Jackson RF, Meredith-Jones KA, Haszard JJ, Galland BC, Morrison S, Jacques M, & Taylor RW. (2025). The Impact of Sleep Loss on Screen Time in Children: Secondary Analyses of a Randomised Crossover Trial Using Objective Measures of Screen Time. Pediatric Obesity: e70050, https://doi.org/10.1111/ijpo.70050.

Haszard JJ, Jackson R, Morrison S, Meredith-Jones KA, Galland BC, Beebe DW, Elder DE, & Taylor RW. (2024). Losing sleep influences dietary intake in children: a longitudinal compositional analysis of a randomised crossover trial. International Journal of Behavioral Nutrition & Physical Activity, 21, 61. https://doi.org/10.1186/s12966-024-01607-5

Morrison S, Jackson R, Haszard JJ, Galland BC, Meredith-Jones KA, Fleming EA, Ward AL, Elder DE, Beebe DW, & Taylor RW. (2023). The effect of modest changes in sleep on dietary intake and eating behavior in children: secondary outcomes of a randomized crossover trial. Amercan Journal of Clinical Nutrition, 117(2):317-325. doi: 10.1016/j.ajcnut.2022.10.007

Taylor RW, Haszard JJ, Jackson R, Morrison S, Beebe DW, Meredith-Jones KA, Elder D, & Galland B. (2023). Effect of Sleep Changes on Health-Related Quality of Life in Healthy Children: A Secondary Analysis of the DREAM Crossover Trial. JAMA Network Open, 6(3):e233005. doi:10.1001/jamanetworkopen.2023.3005

Morrison S, Haszard JJ, Galland BC, Jackson R, Meredith-Jones KA, Elder D, & Taylor RW. (2022). Where does the time go when children don’t sleep? A randomized crossover study. Obesity. 2022; 1- 10. doi:10.1002/oby.23615

Morrison S, Galland BC, Haszard JJ, Jackson R, McIntosh DR, Beebe DW, Elder DE, Ward AL, Meredith-Jones K, & Taylor RW. (2021). Eating in the absence of hunger in children with mild sleep loss: a randomized crossover trial with learning effects. American Journal of Clinical Nutrition, 114(4):1428-1437. https://doi.org/10.1093/ajcn/nqab203

Jackson R, Haszard JJ, Morrison S, Galland BC, McIntosh D, Ward AL, Meredith-Jones KA, & Taylor RW. (2021). Measuring short-term eating behaviour and desire to eat: Validation of the child eating behaviour questionnaire and a computerized 'desire to eat' computerized questionnaire. Appetite, 167, 105661. https://doi.org/10.1016/j.appet.2021.105661

Morrison S, Galland BC, Haszard JJ, Jackson R, McIntosh DR, Beebe DW, Elder DE, Ward AL, Meredith-Jones K, & Taylor RW. (2021). Eating in the absence of hunger in children with mild sleep loss: A randomized crossover trial with learning effects. American Journal of Clinical Nutrition, 114(4), 1428–1437. https://doi.org/10.1093/ajcn/nqab203

Ward AL, Jospe M, Morrison S, Reynolds AN, Kuroko S, Fangupo LJ, Smith C, Galland BC, & Taylor RW. (2021). Bidirectional associations between sleep quality or quantity, and dietary intakes or eating behaviors in children 6–12 years old: A systematic review with evidence mapping. Nutrition Reviews. https://doi.org/10.1093/nutrit/nuaa125

Ward AL, Reynolds AN, Kuroko S, Fangupo LJ, Galland BC, & Taylor RW. (2020). Bidirectional associations between sleep and dietary intake in 0–5 year old children: A systematic review with evidence mapping. Sleep Medicine Reviews, 49, 101231. https://doi.org/10.1016/j.smrv.2019.101231

Ward AL, Galland BC, Haszard JJ, Meredith-Jones K, Morrison S, McIntosh DR, Jackson R, Beebe DW, Fangupo L, Richards R, Te Morenga L, Smith C, Elder DE, & Taylor RW. (2019). The effect of mild sleep deprivation on diet and eating behaviour in children: Protocol for the Daily Rest, Eating, and Activity Monitoring (DREAM) randomized cross-over trial. BMC Public Health, 19(1), 1347. https://doi.org/10.1186/s12889-019-7695-4