Dietary patterns and sleep quality in primary school students with overweight/obesity and normal weight: A case-control study

Abstract

mayonnaise and low consumption of legumes. After calculating the mean score of each pattern and comparing the means, third dietary pattern was the dominant dietary pattern in students with normal weight (Mean = 0.49) and second dietary pattern was the dominant dietary pattern in overweight/obese students (Mean = 0.014). Adherence to the first dietary pattern was associated with 51% lower odds of overweight/obesity (OR: 0.49, 95% CI: 0.24-0.97) among children. This inverse association was also observed when the analysis was performed for overweight and obesity alone. Also high adherence to the second pattern was associated with a 62% lower chance of overweight/obesity (OR: 0.38, 95% CI: 0.15-0.94). However, we found no significant association for the third dietary pattern with overweight/obesity. Furthermore, no significant association existed between sleep quality/duration and overweight/obesity, on the other hand, earlier sleeping reduces the odds of obesity/overweight and the interactions of the dietary patterns and sleep quality/duration with overweight/obesity were not significant. There was no significant difference in the score of the sleep quality questionnaire in the two groups of cases and controls. On the other hand, going to bed early (earlier than 11 pm) reduced the odds of obesity in school children. For example, the odds of obesity/overweight in the crude model decreased by 56% (OR: 0.44, 95% CI: 0.24-0.79) and 58% (OR: 0.42, 95% CI: 0.22-0.81) in the fully adjusted model. Also, the interaction effect of dietary patterns and sleep quality/duration with overweight/obesity and overweight and obesity separately was not significant. Conclusions: Major dietary patterns are different in overweight/obese students and normal weight students. Adherence to the diet containing a high amount of white meats, eggs, vegetables, fruits and juices, nuts, dairy products, whole grains, and a low amount of refined grains and snacks was associated with lower odds of overweight/obesity among elementary school students aged 7 to 13. Obesity in students and this inverse relationship between obesity/overweight with dietary patterns is independent of sleep quality/duration. Late sleeping increases the odds of obesity in students.

ABSTRACT Background and objective: Studies in the past have found a significant relationship between food intake and sleep quality independently with odds of obesity/overweight in children, while studies assessing the realtionship between major dietary patterns and sleep quality with overweight/obesity among school children are rare in Iran. Also, no evidence is available on the interaction effects of these two parameters with overweight/obesity in this age group. The purpose of this study was to determine dietary patterns and sleep quality in overweight/obese and normal weight elementary school students, as well as to investigate the relationship and interaction between dominant dietary patterns and sleep quality/duration with overweight/obesity among elementary school students aged 7 to 13. Methods and materials: The study was a case-control study that was conducted on primary school students who which were randomly selected from 10 elementary schools (6 governmental and 4 non-profit) in Rasht city. Cases were apparently healthy children who had a body mass index percentile of ≥85th for age and sex (n=102). Children with a BMI percentile between 5th and 85th were included in the control group (n=102). Dietary data were collected using a validated 168-item food frequency questionnaire and it was checked by factor analysis method. Sleep quality was assessed by Pittsburgh Sleep Quality Index. Binary logistic regression was used for association between dietary patterns, sleep quality, and odds of obesity. Results: Three dominant dietary patterns were identified under the headings of the first, second and third patterns. The first dietary pattern was characterized by high consumption of pickles, chicken, eggs, vegetables, potatoes, low-fat dairy products and low consumption of liquid oil. Adherence to the second dietary pattern was associated with high consumption of fruits and juices, nuts, high-fat dairy products, fish, olives and olive oil, whole grains and low consumption of refined grains and snacks. In the third pattern, children had high consumption of sugar-sweetened beverages (SSBs), red meat, processed meat and offal, sugar and dessert, solid oil