In the U.S. it is recommended that children consume whole cow's milk (3.5% fat) from ages 1 to 2 years to support rapid early growth and brain development, and then at age 2 years transition to low-fat (1%) or non-fat milk to reduce saturated fat and calorie intake. To date, few studies have examined the optimal milk type for children to prevent obesity. This randomized controlled trial will evaluate the effect of consumption of whole versus 1% milk on child adiposity.
The prevalence of child obesity in the U.S. has tripled since the 1970s and excess weight gain - even in young children - is a precursor to adult obesity and associated co-morbidities. In the U.S. it is recommended that children consume whole cow's milk (3.5% fat) from ages 1 to 2 years to support rapid early growth and brain development, and then at age 2 years transition to low-fat (1%) or non-fat milk to reduce saturated fat and calorie intake. However, surprisingly few rigorous trials to support recommendations on optimal milk type have been conducted and existing observational studies paradoxically suggest that lower fat milk consumption is associated with increased adiposity in children. The effects of the types of fat found in milk on cardiometabolic disease risk have also been questioned. This randomized controlled trial will evaluate the effect of consumption of whole versus 1% milk on child adiposity and other health and developmental outcomes beginning after toddlers have successfully transitioned from breastmilk and/or formula to cow's milk at 2 years of age. Investigators will recruit 625 parents of toddlers and randomly assign 625 toddlers to either whole or 1% milk groups for 1 year (with estimated final sample size of 500). Our primary aim is to determine how milk fat type (whole versus 1%) consumed from age 2 to 3 years affects change in adiposity as measured by waist-to-height ratio (primary outcome), body mass index, tri-ponderal mass index, and waist circumference. Secondary aims are to evaluate how milk type consumed from age 2 to 3 years affects changes in milk, total and saturated fat, added sugars, and total energy intake and overall diet quality, as well as blood lipids and vitamin D status, and neurocognitive development. Results from the Milk-TOT Study can help pediatric health care providers give evidence-based dietary recommendations to improve child weight and health, and can inform the types of milk provided to participants in the federal nutrition programs which collectively provide milk to over half of all young children in the U.S.
Study Type
INTERVENTIONAL
Allocation
Beginning at approximately age 2, milk (equivalent to 2 cups/day) will be provided at no cost to the family for one year.
Parent/caregivers will receive quarterly phone-based counseling by a Registered Dietitian (RD) on how to introduce the toddler to the assigned milk and the importance of continuing to drink the assigned milk for the one year.
Nutrition Policy Institute, University of California Agriculture and Natural Resources
Oakland, California, United States
RECRUITINGChange in waist-to-height ratio
Waist-to-height ratios will be calculated using measured height in m and waist circumference in m.
Time frame: Baseline and 12-months after the start of the study.
Change in body mass index z-score
BMI z-scores will be determined using measured height in m and weight in kg to calculate kg/m\^2, and Centers for Disease Control and Prevention (CDC) growth curves.
Time frame: Baseline and 12-months after the start of the study.
Change in tri-ponderal mass index
Try-ponderal mass index (TMI) will be determined using measured height in m and weight in kg to calculate kg/m\^3.
Time frame: Baseline and 12-months after the start of the study.
Change in waist circumference z-score
Waist circumference z-scores will be determined using measured waist circumference and CDC growth curves.
Time frame: Baseline and 12-months after the start of the study.
Change in dietary intake
Energy (kcals/day), milk (cups/day and %kcals), total dairy (cups/day and %kcals), total fat (g/day and %kcals), saturated fat (g/day and %kcals), added sugars (g/day and %kcals) and calcium (mg/day) intake will be measured using 24-hour recalls.
Time frame: Baseline and 12-months after the start of the study.
Change in diet quality
Diet quality will be measured using the healthy eating index-2020 from 24-hour recalls.
Time frame: Baseline and 12-months after the start of the study.
Change in blood measures
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RANDOMIZED
Purpose
PREVENTION
Masking
NONE
Enrollment
625
Lipid concentrations, glucoregulatory indices, and 25(OH)D concentrations will be measured in a morning blood draw.
Time frame: Baseline and 12-months after the start of the study.
Change in brain growth
Head circumference z-scores will be determined using measured head circumference in cm and CDC growth curves.
Time frame: Baseline and 12-months after the start of the study.
Change in neurocognitive development
Cognitive, communication and physical development scores will be determined using the Developmental Assessment of Young Children-2 tool.
Time frame: Baseline and 12-months after the start of the study.