The effect of healthy nutrition and sleep hygiene education on body weight and related parameters in adolescents

Childhood obesity is a public health problem that is growing every day and paves the way for a range of chronic diseases in adulthood. Sleep deprivation is known to increase the risk of obesity, and sleep patterns are disrupted during adolescence as well as dietary patterns. This randomised controlled clinical trial investigated the effects of nutrition and sleep hygiene education on nutritional status, diet quality, anthropometrical measurements, body weight associated biochemical indicators, sleep habits and sleep quality in preobese and obese adolescents. In the study, 60 pre-obese and obese participants, 38 girls and 22 boys, aged 12-18 years attending an outpatient clinic were followed up with a healthy nutrition education programme for 12 weeks, and at week 6 the participants were randomised into two groups, and the intervention group (n=30) was given sleep hygiene education for the rest 6 weeks in addition to the nutrition education. Participants were interviewed face-to-face at baseline, 6 weeks and 12 weeks, and online at weeks 2, 4, 8 and 10. The face-to-face interviews included a physical examination, blood sampling, anthropometric measurements, a 3-day dietary recall and food frequency questionnaire, and diet quality score which was assessed using the Healthy Eating Index- 2010. Serum leptin and ghrelin levels were analysed by ELISA. Moreover, participants' sleep quality was assessed using the Pittsburgh Sleep Quality Index, sleep hygiene using the Sleep Hygiene Index, chronotype using the Children's Chronotype Scale, night time eating habits using the Night Eating Questionnaire, and sleep habits and social jetlag status using sleep diaries. The online interviews included the assessment of the adherence of healthy nutrition programme and nutritional status in both groups, as well as the adherence to the sleep hygiene education after week 6 in the intervention group. The study showed that dietary intakes of energy, carbohydrate and fat, and the percentage of energy from fat and saturated fat decreased in both groups and genders, while percentage of energy from protein and intakes of total fibre, insoluble fibre, vitamin B6, potassium, magnesium and phosphorus increased by the nutrition education programme (p<0.05 for each). The total HEI-2010 scores of the participants increased from 45.8 (34.8-57.6) to 74.5 (63.4-86.7) in the intervention group and from 44.1 (32.6-57.4) to 69.6 (48.3-77.0) in the control group during the study, and this increase was found to be higher in the intervention group after sleep hygiene education (p<0.001 for each). Body weight, body mass index, waist circumference, waist-to-height ratio and body fat mass decreased in both groups and genders by the nutrition education, and the changes in these parameters were higher in the intervention group than in the control group between week 6 and week 12 (p<0.05 for each). In the both groups, fasting plasma insulin, serum triglycerides and GGT, HOMA-IR, visceral adiposity index and blood pressure levels decreased whereas serum ghrelin levels increased by the nutrition education (p<0.05 for each). Morningness/eveningness scores decreased in both groups, with a greater decrease between week 6 and week 12 in the intervention group (p<0.001 for each). By the nutrition education, mean sleep duration scores increased in both groups, while total sleep quality, night eating questionnaire and sleep hygiene scores decreased, and these changes were more pronounced in the intervention group between week 6 and week 12 (p<0.001 for each). There was a greater decrease in bedtime and social jetlag duration in the intervention group compared to the control group, and a greater increase in weekday morning wake-up time, weekday total sleep time, and weekday time spent in bed (p<0.001 for each). Sleep hygiene education had a positive effect on sleep habits, sleep hygiene, sleep quality, diet quality and anthropometric measurements. In line with these results, it is predicted that planning sleep hygiene education in addition to the nutrition education will have important benefits in the prevention and treatment of obesity and its possible complications in adolescents. Keywords: Obesity, adolescent, nutrition, sleep hygiene, social jetlag