Browsing by Author "Meredith-Jones K"

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    Adolescents’ next-day perceptions of their sleep quality, quantity, sleepiness and sleepiness-related symptoms relative to actigraphy metrics
    (Elsevier B V, 2025-09-01) Tang C; Meredith-Jones K; Haszard JJ; Signal TL; Wickham S-R; Muller D; Taylor R; Galland BC
    Background: Next-day perceptions of sleep and related symptoms are frequently collected in research and clinical practice, but how they correlate with objective sleep measures in adolescents has received little attention. Methods: Participants were aged 16–17 years and without a sleep disorder, anxiety or depression diagnosis. Seven-day wrist actigraphy was collected alongside daily survey ratings of sleep quality, sufficiency, morning and daytime sleepiness, and sleepiness-related mood and concentration. Within-person associations between daily actigraphic sleep metrics (6 variables representing quantity, quality and timing) and subjective ratings were estimated using mixed effects regression models with participant included as a random effect. Results: The sample comprised 71 adolescents (49 % female, 51 % male). No actigraphy metrics linked to sleep sufficiency ratings. Sleep onset was the strongest correlate of sleep quality and morning sleepiness in the expected direction e.g. every 10 min later onset led to a −1.4 point (95 % CI: −2.1, −0.7) drop in the sleep quality score (5-point scale, higher worse), but significant relationships were only in females. While actigraphic sleep quantity metrics were linked to several ratings, all effect sizes were marginal. Sleep quality metrics in the overall sample were not correlated to any ratings. Unexpectedly, timing and quantity metrics linked to sleepiness-related mood ratings, but in the opposite direction hypothesized. Conclusions: The lack of correlation between objective and subjective sleep quality add to the complexity of defining sleep quality accurately. Sleep onset timing, rarely explored in these types of studies emerged as an important correlate of sleep quality perception and other subjective ratings.
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    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
    (BioMed Central Ltd, 2019-10-22) 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
    BACKGROUND: Although insufficient sleep has emerged as a strong, independent risk factor for obesity in children, the mechanisms by which insufficient sleep leads to weight gain are uncertain. Observational research suggests that being tired influences what children eat more than how active they are, but only experimental research can determine causality. Few experimental studies have been undertaken to determine how reductions in sleep duration might affect indices of energy balance in children including food choice, appetite regulation, and sedentary time. The primary aim of this study is to objectively determine whether mild sleep deprivation increases energy intake in the absence of hunger. METHODS: The Daily, Rest, Eating, and Activity Monitoring (DREAM) study is a randomized controlled trial investigating how mild sleep deprivation influences eating behaviour and activity patterns in children using a counterbalanced, cross-over design. One hundred and ten children aged 8-12 years, with normal reported sleep duration of 8-11 h per night will undergo 2 weeks of sleep manipulation; seven nights of sleep restriction by going to bed 1 hr later than usual, and seven nights of sleep extension going to bed 1 hr earlier than usual, separated by a washout week. During each experimental week, 24-h movement behaviours (sleep, physical activity, sedentary behaviour) will be measured via actigraphy; dietary intake and context of eating by multiple 24-h recalls and wearable camera images; and eating behaviours via objective and subjective methods. At the end of each experimental week a feeding experiment will determine energy intake from eating in the absence of hunger. Differences between sleep conditions will be determined to estimate the effects of reducing sleep duration by 1-2 h per night. DISCUSSION: Determining how insufficient sleep predisposes children to weight gain should provide much-needed information for improving interventions for the effective prevention of obesity, thereby decreasing long-term morbidity and healthcare burden. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry ACTRN12618001671257 . Registered 10 October 2018.