The effect of growing up milk with a specific night composition on sleep efficiency, onset, and quality, as well as on memory consolidation and alertness.

It is well known that a good night sleep supports performance the next day. It is also known from literature that a relevant percent of children cope with sleep disturbances. This study aims to improve sleep efficiency in Indonesian children 5-6 years of age by adding specific nutrients to a growing up milk that will be consumed in the evening. At day time in the morning they all will receive a standard growing up milk. An improved sleep efficiency is thought to increase alertness and memory consolidation.

The addition of milk protein hydrolysate and tryptophan rich proteins and/or decreasing stomach emptying rate in combination with increased satiety, will improve sleep onset and efficiency significantly as compared with the current available growing up milk.

Measurements of sleep efficiency, alertness, and memory will take place at the start of the study and after 6 weeks of intervention.

Urine samples will be collected at the start and at the end of the study (after 6 weeks) for the measurement of pH and potassium.

Saliva samples will be collected at the end of the study at 0 and 120 minutes post-consumption of the growing up milk.



Methods of measurement:

1. Sleep efficiency: Measured by 3-days Actiwatch monitoring in combination with a sleep diary;

2. Allertness: Measured by cognitive performance test using the Amsterdam Neuropsychological Tasks (ANT) method, testing at baseline (before consumption) and after 90 and 180 minutes post consumption of the growing up formula;

3. Memory consolidation: Word-pair recall percentage; training (4 times) the evening before the test day. Recall early in the morning just before baseline ANT testing.

A. Standard growing up milk;

B. A + protein hydrolysate + alfa-lactalbumin;

C. A + satiety increasing ingredients.



During 6 weeks the children will receive two servings of growing up milk per day. In the morning this will be the standard growing up milk for all children and in the evening the standard growing up milk (A), or one of the special formulations (B or C). Morning sachets have a white color, evening sachets silver. Measurements will be done at the start of the study and after 6 weeks of consumption.