The purpose of this study is to determine the effects of dairy consumption on short-term cognitive performance, subjective mood and emotions, and glycemic response in healthy children aged 9 - 14 years. The investigators hypothesize that the consumption of dairy products as a mid-morning snack will improve mood and cognitive performance in children. Furthermore, the investigators hypothesize that all dairy products consumed as a mid-morning snack will imbue more benefits on mood and cognitive performance over 2-hours compared to fruit juice or snack skipping.
A randomized within-subject repeated measures experiment will be used to study the effects of dairy product consumption on cognitive performance, subjective mood and emotions, and blood glucose in healthy 9 - 14 year old children. Participants will consume, in a random order on separate mornings, one of the five treatments: (a) milk, (b) yogurt, (c) cheese, (d) fruit juice, or (e) snack skipping. Subjective mood/emotions and cognitive domains (learning and memory, spatial working memory, attention, processing speed, and executive function) will be assessed at baseline (0-min), and 15-, 30-, 60-, and 120-min following treatment consumption. Blood glucose measurements will be collected using the Freestyle Libre 2 continuous glucose monitoring system.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
PREVENTION
Masking
NONE
Enrollment
54
Fat-free milk (500 mL, skim, 0%, Lactantia PurFiltre) will provide 180 kcal, 0 g fat, 26 g carbohydrate, and 18 g protein. Treatments matched for calories (180 kcal).
Fat-free yogurt (242 g, vanilla, 0% Greek, Oikos) will provide 180 kcal, 0 g fat, 23.5 g carbohydrate, and 19.4 g protein. Treatments matched for calories (180 kcal).
Low-fat cheese (60 g, mild marble cheddar, 40% less fat, Selection) will provide 180 kcal, 10 g fat, 2 g carbohydrate, and 16 g protein. Treatments matched for calories (180 kcal).
Centre for Urban Innovation (CUI-109), Toronto Metropolitan University (Formerly Ryerson University)
Toronto, Ontario, Canada
Learning and short-term memory
Cognitive performance tests will be administered via a Dell tablet (Millisecond, Inquisit Web) and paper/pen. Learning and short-term memory will be assessed using an immediate and delayed Word Recall Test (accuracy).
Time frame: Change from baseline (measured at 0-minutes before treatment) and at 15-minutes, 30-minutes, 60-minutes and 120-minutes post-treatment consumption
Spatial working memory
Cognitive performance tests will be administered via a Dell tablet (Millisecond, Inquisit Web) and paper/pen. Spatial working memory will be assessed using the forward and backward versions of the Corsi Block Test (accuracy).
Time frame: Change from baseline (measured at 0-minutes before treatment) and at 15-minutes, 30-minutes, 60-minutes and 120-minutes post-treatment consumption
Sustained attention
Cognitive performance tests will be administered via a Dell tablet (Millisecond, Inquisit Web) and paper/pen. Sustained attention and processing speed will be assessed using the Continuous Performance Test (CPT) (accuracy and reaction time).
Time frame: Change from baseline (measured at 0-minutes before treatment) and at 15-minutes, 30-minutes, 60-minutes and 120-minutes post-treatment consumption
Executive function
Cognitive performance tests will be administered via a Dell tablet (Millisecond, Inquisit Web) and paper/pen. Executive function and selective attention will be assessed using the Flanker Task (accuracy and reaction time).
Time frame: Change from baseline (measured at 0-minutes before treatment) and at 15-minutes, 30-minutes, 60-minutes and 120-minutes post-treatment consumption
Glycemic response
Blood glucose (mmol/L). Blood glucose concentrations will be measured using a Freestyle Libre 2 continuous glucose monitoring (CGM) and flash-glucose system.
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Fruit juice (450 mL, Fruité® Fruit Punch) will provide 180 kcal, 0 g fat, 46.8 g carbohydrate, and 0 g protein. Treatments matched for calories (180 kcal).
Water control treatment (no caloric contribution). Matched for volume (500 mL) to fat-free milk treatment.
Time frame: Change from baseline (measured at 0-minutes before treatment) and 15-minutes, 30-minutes, 45-minutes, 60-minutes, 75-minutes, 90-minutes, 105-minutes and 120-minutes post-treatment consumption
Subjective mood and emotion
A visual analogue scale (VAS) with thirteen questions will be administered to assess subjective emotions and mood (aggression, anger, excitement, disappointment, happiness, upset, frustration, alertness, sadness, tension, exhaustion, calmness, sleepiness, and wellness). Individual questions will be used to form a composite emotion score. Each VAS will be administered via a digital software application (Express VAS, Toronto, Ontario, Canada) on a Dell tablet where children will place an 'X" on the VAS line (100 unit scale) to describe their feelings.
Time frame: Change from baseline (measured at 0-minutes before treatment) and at 15-minutes, 30-minutes, 60-minutes and 120-minutes post-treatment consumption