Sleep studies in I.Family
We studied Dietary Carbohydrate and Nocturnal Sleep Duration in Relation to Children’s Body Mass Index among the IDEFICS Study cohort spread across eight European countries.
Previous research has found that there is a relationship between being overweight and not getting enough sleep. We believed that this relationship could potentially be impacted by a diet high in carbohydrate and that the timing and type of carbohydrate, namely from starch or sugar, could be an important dietary consideration.
To study this, we examined the dietary intake of children participating in the eight-country European study who were recruited from September 2007 to June 2008, when the children were aged two to nine years.
We collected information on lifestyle, dietary intake, height and weight at two occasions. 5,944 children where included in the study in 2007 and 4,301 were re-examined two years later. For each meal occasion morning, midday, and evening, which can be thought of as breakfast, lunch and dinner plus related snacks, we assessed starch intake in grams and sugar intake in grams. We then divided the grams of starch and sugar by total energy intake (EI) in kilocalories. To assign high carbohydrate intake from starch and high carbohydrate intake from sugar we divide the whole group into four by the proportion of carbohydrate intake. Those in the highest intake group were categorized as high carbohydrate consumers by starch and sugar separately and for each meal.
We found that short sleep duration as well as high carbohydrate-starch in the morning was positively associated with body mass index (BMI) z-scores. Further high carbohydrate-starch at midday was positively associated with body mass index (BMI) z-scores in children with short sleep duration, and negatively associated with BMI z-scores in those with normal sleep duration in 2007/2008. However, this relationship did not persist over the two years of follow-up.
Our observations offer a perspective on the best timing for macronutrient consumption, which is known to be influenced by circadian rhythms or our sleep and wake cycles. Reduced carbohydrate intake, especially during morning and midday meals, and following night time sleep duration recommendations are two factors that may protect children from being overweight and both are factors that can be modified.