An interventional study of Active group in Childhood Obesity Prevention, Childhood Obesity and Physical Activity, sponsored by Joslin Diabetes Center. Recruiting at 2 sites in United States. Open to female participants aged 18 Years to 45 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-03-12.
Sponsored by Joslin Diabetes Center · Not applicable, Interventional, and Prevention
The purpose of this study is to learn how exercise and physical activity during pregnancy and after pregnancy may affect the composition of breastmilk. Certain changes in breast milk after exercise may have an impact on how infants use energy. Understanding this process may improve public health recommendations for exercise during and after pregnancy. This study can help investigators learn more about how maternal exercise patterns may affect body growth and obesity risk in infants who are breastfed. This research may help identify how different factors can influence healthy weight and early development in infants.
Epidemiological studies suggest that breastfeeding protects against risk of obesity, diabetes, asthma, and other childhood diseases. However, the specific compounds within breastmilk that are responsible for its protective effects are not fully understood. Moreover, prior work from this investigative team has shown that human milk composition varies substantially between individuals according to factors such as body mass index (BMI), diabetes status, diet, and physical activity. Gaining a better understanding of how modifiable risk factors may impact human milk composition would have the potential to identify strategies to enhance the health-promoting benefits of human milk.
In this project, the investigators will study the impact of maternal exercise on human milk composition. The central hypothesis is that maternal exercise induces changes in breast milk metabolites and lipids that result in activation of infant brown fat, increased infant energy expenditure, and reduced obesity risk.
The study will include assessments of habitual activity during pregnancy and the postpartum period, supervised bouts acute moderate exercise, as well as analysis of human milk composition, infant growth and body composition, and infant energy expenditure.
1,129 studies on the registry are indexed under Pediatric Obesity; 187 are open to participants now.
This study's planned enrollment of 200 is above the median of 100 across 870 interventional studies indexed under Pediatric Obesity.
Browse Pediatric Obesity studies →Joslin Diabetes Center is the lead sponsor of 80 studies on the registry; 7 are open to participants now.
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Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
A blood test of average blood sugar over the past two to three months, given as a percentage or in mmol/mol. 6.5% (48 mmol/mol) or more is the usual threshold for diabetes, normally confirmed by a second test.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HbA1c
A blood test of average blood sugar over the past two to three months, given as a percentage or in mmol/mol. 6.5% (48 mmol/mol) or more is the usual threshold for diabetes, normally confirmed by a second test.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants in this group will be encouraged to engage in daily physical activity
Behavioral: Active group
Usual care
For participants randomized to the Active group, there will be weekly phone calls with study staff during which step counts and exercise bouts from the previous week will be reviewed, and exercise goals for the following week will be gradually increased.
Altered breast milk lipidome
Milk composition measured through lipidomics
Time frame: 8 weeks
Altered breast milk metabolome
Human milk composition measured via metabolomics
Time frame: 8 weeks
Infant body composition
Infant body composition will be measured using air-displacement plethysmography (ADP; i.e., PeaPod) at 1 and 3-mo and by DXA at 6 and 12-mo: percentage fat, total fat mass.
Time frame: 3 months, 6 months, and 12 months
Infant body mass index (BMI)
Body mass index (BMI) z-score for age and sex, usual range \[-4,4\]; lower BMI z-score represents lower adiposity
Time frame: 3 months, 6 months, and 12 months
Infant resting metabolic rate
Infant Resting Metabolic Rate
Time frame: 3 months of age
Infant brown adipose tissue anatomy
MRI measurement of brown adipose tissue (BAT) volume and distribution
Time frame: 2 months
Heat production
Infant Infrared Thermography to measure brown adipose tissue activity
Time frame: 1 month and 3 months
Plan to share: Undecided
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Joslin Diabetes Center