Three-year follow-up of a randomised controlled trial to reduce excessive weight gain in the first two years of life: protocol for the POI follow-up study

Rachael W Taylor, Anne-Louise M Heath, Barbara C Galland, Sonya L Cameron, Julie A Lawrence, Andrew R Gray, Gerald W Tannock, Blair Lawley, Dione Healey, Rachel M Sayers, Maha Hanna, Kim Meredith-Jones, Burt Hatch, Barry J Taylor, Rachael W Taylor, Anne-Louise M Heath, Barbara C Galland, Sonya L Cameron, Julie A Lawrence, Andrew R Gray, Gerald W Tannock, Blair Lawley, Dione Healey, Rachel M Sayers, Maha Hanna, Kim Meredith-Jones, Burt Hatch, Barry J Taylor

Abstract

Background: The Prevention of Overweight in Infancy (POI) study was a four-arm randomised controlled trial (RCT) in 802 families which assessed whether additional education and support on sleep (Sleep group); food, physical activity and breastfeeding (FAB group); or both (Combination group), reduced excessive weight gain from birth to 2 years of age, compared to usual care (Control group). The study had high uptake at recruitment (58 %) and retention at 2 years (86 %). Although the FAB intervention produced no significant effect on BMI or weight status at 2 years, the odds of obesity were halved in those who received the sleep intervention, despite no apparent effect on sleep duration. We speculate that enhanced self-regulatory behaviours may exist in the Sleep group. Self-regulation was not measured in our initial intervention, but extensive measures have been included in this follow-up study. Thus, the overall aim of the POI follow-up is to determine the extent to which augmented parental support and education on infant sleep, feeding, diet, and physical activity in the first 2 years of life reduces BMI at 3.5 and 5 years of age, and to determine the role of self-regulation in any such relationship.

Methods/design: We will contact all 802 families and seek renewed consent to participate in the follow-up study. The families have received no POI intervention since the RCT finished at 2 years of age. Follow-up data collection will occur when the children are aged 3.5 and 5 years (i.e. up to 3 years post-intervention). Outcomes of interest include child anthropometry, body composition (DXA scan), diet (validated food frequency questionnaire), physical activity (accelerometry), sleep (questionnaire and accelerometry), and self-regulation (questionnaires and neuropsychological assessment).

Discussion: Our follow-up study has been designed primarily to enable us to determine whether the intriguing benefit of the sleep intervention suggested at 2 years of age remains as children approach school age. However, cohort analyses will also investigate how BMI, self-regulation, and sleep consolidation develop during the early years. This information will be valuable to researchers and policy makers progressing the field of early childhood obesity prevention.

Trial registration: ClinicalTrials.gov number NCT00892983 .

Keywords: Child; Diet; Infant; Obesity; Physical activity; Prevention; Self-regulation; Sleep.

References

    1. World Health Organization. Global strategy on diet, physical activity, and health: childhood overweight and obesity. . Accessed: 13 November 2015.
    1. Ng M, Fleming T, Robinson M, Thomson B, Graetz N, Margono C, Mullany EC, Biryukov S, Abbafati C, Abera SF, et al. Global, regional, and national prevalence of overweight and obesity in children and adults during 1980–2013: a systematic analysis for the Global Burden of Disease Study 2013. Lancet. 2014;384:766–781. doi: 10.1016/S0140-6736(14)60460-8.
    1. Skinner AC, Perrin EM, Skelton JA. Prevalence of obesity and severe obesity in US children, 1999–2014. Obesity. 2016;24:1116–1123. doi: 10.1002/oby.21497.
    1. Ministry of Health. Annual update of key results 2014/15: New Zealand Health Survey. . Accessed: 28 April 2016.
    1. Shibli R, Rubin L, Akons H, Shaoul R. Morbidity of overweight (≥85th percentile) in the first 2 years of life. Pediatrics. 2008;122:267–272. doi: 10.1542/peds.2007-2867.
    1. Druet C, Stettler N, Sharp S, Simmons RK, Cooper C, Smith GD, Ekelund U, Levy-Marchal C, Jarvelin MR, Kuh D, et al. Prediction of childhood obesity in infancy weight gain: an individual-level meta-analysis. Paediatr Perinat Epidemiol. 2012;26:19–26. doi: 10.1111/j.1365-3016.2011.01213.x.
    1. Gillman MW, Ludwig DS. How early should obesity prevention start? N Engl J Med. 2013;369:2173–2175. doi: 10.1056/NEJMp1310577.
    1. Taveras EM, Gillman MW, Kleinman KP, Rich-Edwards JW, Rifas-Shiman SL. Reducing racial/ethnic disparities in childhood obesity: the role of early life risk factors. JAMA Pediatr. 2013;167:731–738. doi: 10.1001/jamapediatrics.2013.85.
    1. Malik VS, Willett WC, Hu FB. Global obesity: trends, risk factors and policy implications. Nat Rev Endocrinol. 2013;9:13–27. doi: 10.1038/nrendo.2012.199.
    1. Silventoinen K, Rokholm B, Kaprio J, Sørensen TI. The genetic and environmental influences on childhood obesity: a systematic review of twin and adoption studies. Int J Obes. 2010;34:29–40. doi: 10.1038/ijo.2009.177.
    1. Karlsson CL, Onnerfalt J, Xu J, Molin G, Ahrné S, Thorngren-Jerneck K. The microbiota of the gut in preschool children with normal and excessive body weight. Obesity (Silver Spring) 2012;20:2257–2261. doi: 10.1038/oby.2012.110.
    1. Lumeng JC, Taveras EM, Birch L, Yanovski SZ. Prevention of obesity in infancy and early childhood: a National Institutes of Health workshop. JAMA Pediatr. 2015;169:484–490. doi: 10.1001/jamapediatrics.2014.3554.
    1. Chen X, Beydoun MA, Wang Y. Is sleep duration associated with childhood obesity? A systematic review and meta-analysis. Obesity. 2008;16:265–274. doi: 10.1038/oby.2007.63.
    1. Chan RS, Woo J. Prevention of Overweight and Obesity: How Effective is the Current Public Health Approach. Int J Environ Res Public Health. 2010;7:765–783. doi: 10.3390/ijerph7030765.
    1. Lobstein T. The prevention of obesity in children. Pediatr Endocrinol Rev. 2004;1(Suppl 3):471–475.
    1. West F, Sanders MR, Cleghorn GJ, Davies PS. Randomised clinical trial of a family-based lifestyle intervention for childhood obesity involving parents as the exclusive agents of change. Behav Res Ther. 2010;48:1170–1179. doi: 10.1016/j.brat.2010.08.008.
    1. Gerards SM, Sleddens EF, Dagnelie PC, de Vries NK, Kremers SP. Interventions addressing general parenting to prevent or treat childhood obesity. Int J Pediatr Obes. 2011;6:e28–e45. doi: 10.3109/17477166.2011.575147.
    1. Sleddens EF, Gerards SM, Thijs C, de Vries NK, Kremers SP. General parenting, childhood overweight and obesity-inducing behaviors: a review. Int J Pediatr Obes. 2011;6:e12–e27. doi: 10.3109/17477166.2011.566339.
    1. Topham GL, Page MC, Hubbs-Tait L, Rutledge JM, Kennedy TS, Shriver L, Harrist AW. Maternal depression and socio-economic status moderate the parenting style/child obesity association. Public Health Nutr. 2010;13:1237–1244. doi: 10.1017/S1368980009992163.
    1. Bergmeier H, Skouteris H, Horwood S, Hooley M, Richardson B. Associations between child temperament, maternal feeding practices and child body mass index during the preschool years: a systematic review of the literature. Obes Rev. 2014;15:9–18. doi: 10.1111/obr.12066.
    1. Wu T, Dixon WE, Jr, Dalton WT, 3rd, Tudiver F, Liu X. Joint effects of child temperament and maternal sensitivity on the development of childhood obesity. Matern Child Health J. 2011;15:469–477. doi: 10.1007/s10995-010-0601-z.
    1. Birch LL, Doub AE. Learning to eat: birth to age 2. Am J Clin Nutr. 2014;99:723S–728S. doi: 10.3945/ajcn.113.069047.
    1. Rothbart MK, Sheese BE. Posner. Developing mechanisms of self-regulation in early life. Emotion Review. 2011;3:207–13. doi: 10.1177/1754073910387943.
    1. Blake-Lamb TL, Locks L, Perkins ME, Woo Baidal JA, Cheng ER, Taveras EM. Interventions for childhood obesity in the first 1000 days. A systematic review. Am J Prev Med. 2016;50:780–789. doi: 10.1016/j.amepre.2015.11.010.
    1. Redsell SA, Edmonds B, Swift JA, Siriwardena AN, Weng S, Nathan D, Glazebrook C. Systematic review of randomised controlled trials of interventions that aim to reduce the risk, either directly or indirectly, of overweight and obesity in infancy and early childhood. Matern Child Nutr. 2016;12:24–38. doi: 10.1111/mcn.12184.
    1. Paul IM, Savage JS, Anzman SL, Beiler JS, Marini ME, Stokes JL, Birch LL. Preventing obesity during infancy: a pilot study. Obesity. 2011;19:353–361. doi: 10.1038/oby.2010.182.
    1. Verbestel V, De Coen V, Van Winckel M, Huybrechts I, Maes L, De Bourdeaudhuij I. Prevention of overweight in children younger than 2 years old: a pilot cluster-randomized controlled trial. Public Health Nutr. 2014;17:1384–1392. doi: 10.1017/S1368980013001353.
    1. Mustila T, Raitanen J, Keskinen P, Saari A, Luoto R. Pragmatic controlled trial to prevent childhood obesity in maternity and child health care clinics: pregnancy and infant weight outcomes (the VACOPP Study) BMC Pediatr. 2013;13:80. doi: 10.1186/1471-2431-13-80.
    1. Navarro JI, Sigulem DM, Ferraro AA, Polanco JJ, Barros AJD. The double task of preventing malnutrition and overweight: a quasi- experimental community-based trial. BMC Public Health. 2013;13:212. doi: 10.1186/1471-2458-13-212.
    1. Wen LM, Baur LA, Simpson JM, Rissel C, Wardle K, Flood VM. Effectiveness of home based early intervention on children’s BMI at age 2: randomised controlled trial. BMJ. 2012;344:e3732. doi: 10.1136/bmj.e3732.
    1. Campbell KJ, Lioret S, McNaughton SA, Crawford DA, Salmon J, Ball K, McCallum Z, Gerner BE, Spence AC, Cameron AJ, et al. A parent-focused intervention to reduce infant obesity risk behaviors: a randomized trial. Pediatrics. 2013;131:652–660. doi: 10.1542/peds.2012-2576.
    1. Daniels LA, Mallan KM, Nicholson JM, Battistutta D, Magarey A. Outcomes of an early feeding practices intervention to prevent childhood obesity. Pediatrics. 2013;132:e109–e118. doi: 10.1542/peds.2012-2882.
    1. Wen LM, Baur LA, Simpson JM, Xu H, Hayes AJ, Hardy LL, Williams M, Rissel C. Sustainability of effects of an early childhood obesity prevention trial over time: a further 3-year follow-up of the Healthy Beginnings Trial. JAMA Pediatr. 2015;169:543–551. doi: 10.1001/jamapediatrics.2015.0258.
    1. Daniels LA, Mallan KM, Nicholson JM, Thorpe K, Nambiar S, Mauch CE, Magarey A. An early feeding practices intervention for obesity prevention. Pediatrics. 2015;136:e40–e49. doi: 10.1542/peds.2014-4108.
    1. Hnatiuk J, Ridgers ND, Salmon J, Campbell K, McCallum Z, Hesketh K. Physical activity levels and patterns of 19-month-old children. Med Sci Sports Exerc. 2012;44:1715–1720. doi: 10.1249/MSS.0b013e31825825c4.
    1. Forsyth BW, Leventhal JM, McCarthy PL. Mothers’ perceptions of problems of feeding and crying behaviour. Am J Dis Child. 1985;139:269–272. doi: 10.1001/archpedi.1985.02140050063023.
    1. Sepa A, Frodi A, Ludvigsson J. Psychosocial correlates of parenting stress, lack of support and lack of confidence/security. Scand J Psychol. 2004;45:169–179. doi: 10.1111/j.1467-9450.2004.00392.x.
    1. Taylor BJ, Heath A-LM, Galland BC, Gray AR, Lawrence JA, Sayers R, Dale K, Coppell KJ, Taylor RW. Prevention of Overweight in Infancy () study: a randomised controlled trial of sleep, food and activity interventions for preventing overweight from birth. BMC Public Health. 2011;11:942. doi: 10.1186/1471-2458-11-942.
    1. Ministry of Health, New Zealand. Well Child/Tamariki Ora. . Accessed: June 2016.
    1. Cameron SL, Heath A-LM, Gray AR, Churcher B, Davies RS, Newlands A, Galland BC, Sayers RM, Lawrence JA, Taylor BJ, et al. Lactation consultant support from late pregnancy with an educational intervention at 4 months of age delays the introduction of complementary foods in a randomized controlled trial. J Nutr. 2015;145:1481–1490. doi: 10.3945/jn.114.202689.
    1. Fangupo LJ, Heath A-L, Williams SM, Somerville MR, Lawrence JA, Gray AR, Taylor BJ, Mills VC, Watson EO, Galland BC, et al. Impact of an early-life intervention on the nutrition behaviors of 2-year old children: a randomized controlled trial. Am J Clin Nutr. 2015;102:704–712. doi: 10.3945/ajcn.115.111823.
    1. Wen LM, Baur LA, Rissel C, Wardle K, Alperstein G, Simpson JM. Early intervention of multiple home visits to prevent childhood obesity in a disadvantaged population: a home-based randomised controlled trial (Healthy Beginnings Trial) BMC Public Health. 2007;7:76. doi: 10.1186/1471-2458-7-76.
    1. Daniels LA, Magarey A, Battistutta D, Nicholson JM, Farrell A, Davidson G, Cleghorn G. The NOURISH randomised control trial: Positive feeding practices and food preferences in early childhood – a primary prevention program for childhood obesity. BMC Public Health. 2009;9:387. doi: 10.1186/1471-2458-9-387.
    1. Campbell K, Hesketh K, Crawford D, Salmon J, Ball K, McCallum Z. The Infant Feeding Activity and Nutrition Trial (INFANT) an early intervention to prevent childhood obesity: cluster-randomised controlled trial. BMC Public Health. 2008;8:103. doi: 10.1186/1471-2458-8-103.
    1. Askie LM, Baur LA, Campbell K, Daniels L, Hesketh K, Magarey A, Mihrshahi S, Rissel C, Simes J, Taylor B, et al. The Early Prevention of Obesity in CHildren (EPOCH) Collaboration – an individual patient data prospective meta-analysis. BMC Public Health. 2010;10:728. doi: 10.1186/1471-2458-10-728.
    1. Hart CN, Cairns A, Jelalian E. Sleep and obesity in children and adolescents. Pediatr Clin N Am. 2011;58:715–733. doi: 10.1016/j.pcl.2011.03.007.
    1. Galland BC, Mitchell EA. Helping children sleep. Arch Dis Child. 2010;95:850–853. doi: 10.1136/adc.2009.162974.
    1. Nielsen LS, Danielsen KV, Sørensen TIA. Short sleep duration as a possible cause of obesity: critical analysis of the epidemiological evidence. Obes Rev. 2011;12:78–92. doi: 10.1111/j.1467-789X.2010.00724.x.
    1. Carter PJ, Taylor BJ, Williams SM, Taylor RW. A longitudinal analysis of sleep in relation to BMI and body fat in children: the FLAME study. BMJ. 2011;342:d2717. doi: 10.1136/bmj.d2717.
    1. Fatima Y, Doi SAR, Mamun AA. Longitudinal impact of sleep on overweight and obesity in children and adolescents: a systematic review and bias-adjusted meta-analysis. Obes Rev. 2015;16:137–149. doi: 10.1111/obr.12245.
    1. Haines J, McDonald J, O’Brien A, et al. Healthy habits, happy homes: Randomized trial to improve household routines for obesity prevention among preschool-aged children. JAMA Pediatr. 2013;167:1072–1079. doi: 10.1001/jamapediatrics.2013.2356.
    1. Wake M, Price A, Clifford S, Ukoumunne OC, Hiscock H. Does an intervention that improves infant sleep also improve overweight at age 6? Follow-up of a randomised trial. Arch Dis Child. 2011;96:526–532. doi: 10.1136/adc.2010.196832.
    1. Yoong SL, Chai LK, Williams CM, Wiggers J, Finch M, Wolfenden L. Systematic review and meta-analysis of interventions targeting sleep and their impact on body mass index, diet, and physical activity. Obesity. 2016;24:1140–1147. doi: 10.1002/oby.21459.
    1. Sadeh A, Tikotzky L, Scher A. Parenting and infant sleep. Sleep Med Rev. 2010;14:89–96. doi: 10.1016/j.smrv.2009.05.003.
    1. Galland B, Taylor B, Gray A, Heath A, Lawrence J, Sayers R, Cameron S, Hanna M, Dale K, Coppell K, et al. Early life prevention of obesity by targeting sleep, or food and activity: a randomized controlled trial. SLEEP. 2016;39:A399.
    1. Schmid SM, Hallschmid M, Schultes B. The metabolic burden of sleep loss. Lancet Diab Endocrinol. 2015;3:52–62. doi: 10.1016/S2213-8587(14)70012-9.
    1. Gluckman PD, Hanson M, Zimmet P, Forrester T. Losing the war against obesity: the need for a developmental perspective. Sci Transl Med. 2011;3:93cm19. doi: 10.1126/scitranslmed.3002554.
    1. Mindell JA, Telofski LS, Wiegand B, Kurtz ES. A nightly bedtime routine: impact on sleep in young children and maternal mood. Sleep. 2009;32:599–606.
    1. Francis LA, Susman EJ. Self-regulation and rapid weight gain in children from age 3 to 12 years. Arch Pediatr Adolesc Med. 2009;163:297–302. doi: 10.1001/archpediatrics.2008.579.
    1. Moffitt TE, Arseneault L, Belsky D, Dickson N, Hancox RJ, Harrington H, Houts R, Poulton R, Roberts BW, Ross S, et al. A gradient of childhood self-control predicts health, wealth, and public safety. Proc Natl Acad Sci U S A. 2011;108:2693–2698. doi: 10.1073/pnas.1010076108.
    1. Caleza C, Yañez-Vico RM, Mendoza A, Iglesias-Linares A. Childhood obesity and delayed gratification behavior: a systematic review of experimental studies. J Pediatr. 2015;169:201–207. doi: 10.1016/j.jpeds.2015.10.008.
    1. St James-Roberts I, Roberts M, Hovish K, Owen C. Video Evidence That London Infants Can Resettle Themselves Back to Sleep After Waking in the Night, as well as Sleep for Long Periods, by 3 Months of Age. J Dev Behav Pediatr. 2015;36:324–329. doi: 10.1097/DBP.0000000000000166.
    1. Korkman M, Kirk UKS. NEPSY – Second Edition (NEPSY-II) San Antonio: Pearson Education; 2007.
    1. McClelland MM, Cameron CE. Self-regulation in early childhood: Improving conceptual clarity and developing ecologically valid measures. Child Dev Perspect. 2011;6:136–142. doi: 10.1111/j.1750-8606.2011.00191.x.
    1. Reilly JJ, Jackson DM, Montgomery C, Kelly LA, Slater C, Grant S, Paton JY. Total energy expenditure and physical activity in young Scottish children: mixed longitudinal study. Lancet. 2004;363:211–212. doi: 10.1016/S0140-6736(03)15331-7.
    1. Hinkley T, Salmon J, Okely AD, Crawford D, Hesketh KD. Preschoolers’ physical activity, screen time, and compliance with recommendations. Med Sci Sports Exerc. 2012;44:458–465. doi: 10.1249/MSS.0b013e318233763b.
    1. Vale S, Trost S, Ruiz J, Rêgo C, Moreira P, Mota J. Physical activity guidelines and preschooler’s obesity status. Int J Obes. 2013;37:1352–1355. doi: 10.1038/ijo.2013.109.
    1. Taylor RW, Murdoch L, Carter P, Gerrard DF, Williams SM, Taylor BJ. Longitudinal study of physical activity and inactivity in preschoolers: FLAME study. Med Sci Sports Exerc. 2009;41:96–102. doi: 10.1249/MSS.0b013e3181849d81.
    1. Cliff DP, Reilly JJ, Okely AD. Methodological considerations in using accelerometers to assess habitual physical activity in children aged 0–5 years. J Sci Med Sport. 2009;12:557–567. doi: 10.1016/j.jsams.2008.10.008.
    1. Van Cauwenberghe E, Gubbels J, De Bourdeaudhuij I, Cardon G. Feasibility and validity of accelerometer measurements to assess physical activity in toddlers. Int J Behav Nutr Phys Act. 2011;8:67. doi: 10.1186/1479-5868-8-67.
    1. Hnatiuk J, Salmon J, Hinkley T, Okely A, Trost S. A review of preschool children’s physical activity and sedentary time using objective measures. Am J Prev Med. 2014;47:487–497. doi: 10.1016/j.amepre.2014.05.042.
    1. Meredith-Jones K, Williams SM, Galland BC, Kennedy G, Taylor RW. 24h accelerometry: Impact of sleep-screening methods on estimates of physical activity and sedentary time. J Sports Sci. 2016;34:679–685. doi: 10.1080/02640414.2015.1068438.
    1. Ly NP, Litonjua A, Gold DR, Celedon JC. Gut microbiota, probiotics, and vitamin D: interrelated exposures influencing allergy, asthma, and obesity? J Allergy Clin Immunol. 2011;127:1087–1094. doi: 10.1016/j.jaci.2011.02.015.
    1. Harley ITW, Karp CL. Obesity and the gut microbiome: striving for causality. Mol Metab. 2012;1:21–31. doi: 10.1016/j.molmet.2012.07.002.
    1. Angelakis E, Armougom F, Million M, Raoult D. The relationship between gut microbiota and weight gain in humans. Future Microbiol. 2012;7:91–109. doi: 10.2217/fmb.11.142.
    1. Chang L, Neu J. Early factors leading to later obesity: interactions of the microbiome, epigenome, and nutrition. Curr Probl Pediatr Adolesc Health Care. 2015;45:134–142. doi: 10.1016/j.cppeds.2015.03.003.
    1. Kalliomaki M, Collado MC, Salminen S, Isolauri E. Early difference in fecal microbiota composition in children may predict overweight. Am J Clin Nutr. 2008;87:534–538.
    1. Luoto R, Kalliomaki M, Laitinen K, Delzenne NM, Cani PD, Salminen S, Isolauri E. Initial dietary and microbiological environments deviate in normal-weight compared to overweight children at 10 years of age. J Pediatr Gastroenterol Nutr. 2011;52:90–95. doi: 10.1097/MPG.0b013e3181f3457f.
    1. Scheepers LEJM, Penders J, Mbakwa CA, Thijs C, Mommers M, Arts ICW. The intestinal microbiota composition and weight development in children: the KOALA Birth Cohort study. Int J Obes. 2015;39:16–25. doi: 10.1038/ijo.2014.178.
    1. Weden MM, Brownell PB, Rendall MS, Lau C, Fernandes M, Zafar N. Parent-reported height and weight as sources of bias in survey estimates of childhood obesity. Am J Epidemiol. 2013;178:461–473. doi: 10.1093/aje/kws477.
    1. Conterno L, Fava F, Viola R, Tuohy KM. Obesity and the gut microbiota: does up-regulating colonic fermentation protect against obesity and metabolic disease? Genes Nutr. 2011;6:241–260. doi: 10.1007/s12263-011-0230-1.
    1. de Onis M, Onyango AW, Van den Broeck J, Chumlea WC, Martorell R. Measurement and standardization protocols for anthropometry used in the construction of a new international growth reference. Food Nutr Bull. 2004;25:S27–S36. doi: 10.1177/15648265040251S104.
    1. WHO Multicentre Growth Reference Study Group. WHO Child Growth Standards based on length/height, weight and age. Acta Paediatr. 2006;450(Suppl):76–85.
    1. Ponitz CC, McClelland MM, Matthews JS, Morrison FJ. A structured observation of behavioral self-regulation and its contribution to kindergarten outcomes. Dev Psychol. 2009;45:605–619. doi: 10.1037/a0015365.
    1. Reynolds CR, Kamphaus RW. BASC-2: Behavior Assessment System for Children. Second. Bloomington: Pearson Assessments; 2004.
    1. Rothbart MK, Ahadi SA, Hershey KL, Fisher P. Investigations of temperament at three to seven years: the Children’s Behavior Questionnaire. Child Dev. 2001;72:1394–1408. doi: 10.1111/1467-8624.00355.
    1. Tan CC, Holub SC. Children’s Self-Regulation in Eating: Associations with Inhibitory Control and Parents’ Feeding Behavior. J Pediatr Psychol. 2011;36:340–345. doi: 10.1093/jpepsy/jsq089.
    1. Taylor RW, Jones IE, Williams SM, Goulding A. An evaluation of waist circumference, waist-to-hip ratio and the conicity index to screen for high trunk fat, as measured by dual-energy x-ray absorptiometry in children aged 3–19 y. Am J Clin Nutr. 2000;72:490–495.
    1. Taylor RW, Grant AM, Williams SM, Goulding A. Sex differences in regional body fat distribution from pre- to postpuberty. Obesity. 2009;18:1410–1416. doi: 10.1038/oby.2009.399.
    1. Galland BC, Kennedy G, Mitchell EA, Taylor BJ. Algorithms for using an activity-based accelerometer for identification of infant sleep-wake states during nap studies. Sleep Med. 2012;13:743–751. doi: 10.1016/j.sleep.2012.01.018.
    1. Galland BC, Meredith-Jones K, Gray A, Taylor BJ, Taylor RW. Criteria for nap identification in infants and young children using 24-h actigraphy and agreement with parental diary. Sleep Med. 2016;9:85–92. doi: 10.1016/j.sleep.2015.10.013.
    1. Evenson KR, Catellier DJ, Gill K, Ondrak KS, McMurray RG. Calibration of two objective measures of physical activity for children. J Sports Sci. 2008;26:1557–1565. doi: 10.1080/02640410802334196.
    1. Trost SG, Loprinzi PD, Moore R, Pfeiffer KA. Comparison of accelerometer cut points for predicting acitivity intensity in youth. Med Sci Sports Exerc. 2011;43:1360–1368. doi: 10.1249/MSS.0b013e318206476e.
    1. Bruni O, Ottavianio S, Guidetti V, Romoli M, Innocenzi M, Cortesi F, Giannotti F. The Sleep Disturbance Scale for Children (SDSC): Construction and validation of an instrument to evaluate sleep disturbances in childhood and adolescence. J Sleep Res. 1996;5:251–261. doi: 10.1111/j.1365-2869.1996.00251.x.
    1. Watson EO, Heath A-LM, Taylor RW, Mills VC, Barris A, Skidmore PML. Relative validity and reproducibility of a food frequency questionnaire to determine nutrient intakes of New Zealand toddlers aged 12–24 months. Public Health Nutr. 2015;115:551–558.
    1. Mills VC, Skidmore PML, Watson EO, Taylor RW, Heath A-LM. Relative validity and reproducibility of a food frequency questionnaire for identifying the dietary patterns of New Zealand toddlers. J Acad Nutr Diet. 2015;115:551–558. doi: 10.1016/j.jand.2014.09.016.
    1. Caporaso JG, Kuczynski J, Stombaugh J, Bittinger K, Bushman FD, Costello EK, Fierer N, Gonzalez Peña A, Goodrick JK, Gordon JI, et al. QIIME allows analysis of high-throughput community sequencing data. Nat Methods. 2010;7:335–336. doi: 10.1038/nmeth.f.303.
    1. Sauvé B, Koren G, Walsh G, Tokmakejian S, Van Uum SHM. Measurement of cortisol in human hair as a biomarker of systemic exposure. Clin Invest Med. 2007;30:E183–E191.
    1. Russell E, Koren G, Rieder M, Van Uum S. Hair cortisol as a biological marker of chronic stress: current status, future directions and unanswered questions. Psychoneuroendocrinology. 2012;37:589–601. doi: 10.1016/j.psyneuen.2011.09.009.
    1. Lovibond SH, Lovibond PF. Manual for the Depression Anxiety Stress Scales. 2. Sydney: Psychology Foundation; 1995.
    1. Katan BC. Bias in randomised factorial trials. Stat Med. 2013;32:4540–4549. doi: 10.1002/sim.5869.
    1. Katan BC, Morris TP. Improper analysis of triala randomised using stratified blocks or minimisation. Stat Med. 2012;31:328–340. doi: 10.1002/sim.4431.
    1. White IR, Horton NJ, Carpenter J, Pocock SJ. Strategy for intention to treat analysis in randomised trials with missing outcome data. BMJ. 2011;342:d40. doi: 10.1136/bmj.d40.
    1. Meltzer LJ, Montgomery-Downs HE, Insana SP, Walsh CM. Use of actigraphy for assessment in pediatric sleep research. Sleep Med Rev. 2012;16:463–475. doi: 10.1016/j.smrv.2011.10.002.

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