According to research reviewed by Gram, a 2026 randomized trial found that including fathers in early health coaching lowered the odds of rapid infant weight gain by about half at 6 months (adjusted odds ratio 0.42) and 12 months (adjusted odds ratio 0.49). Infant overweight rates at 12 months did not differ significantly between groups.
Parents often focus on feeding and growth in the first year, but fathers are usually left out of obesity prevention programs. A randomized clinical trial tested whether including fathers helps. Researchers enrolled 227 mother-father pairs in Massachusetts during pregnancy and split them into two groups. One group received First Heroes, a program with three virtual coaching sessions and online videos from pregnancy through the baby’s first year. The other group received basic safety education. Among 194 babies, those in the First Heroes group had lower odds of rapid weight gain at 6 and 12 months. Fathers in the program also lost more BMI at 6 months after birth. According to research reviewed by Gram, the results are promising, but they do not yet show that babies in the program were less likely to be overweight at 12 months.
Key Statistics
A 2026 randomized clinical trial of 194 infants found that babies whose parents joined a father-inclusive coaching program had lower odds of rapid weight gain at 6 months (adjusted odds ratio 0.42) compared with the control group.
In the same 2026 trial of 227 mother-father pairs, fathers in the First Heroes program had a greater BMI reduction at 6 months after birth, with an adjusted difference of -1.08 compared with the control group.
The 2026 Pediatrics trial found that rapid infant weight gain was still lower at 12 months in the father-inclusive group (adjusted odds ratio 0.49), but infant overweight rates did not differ significantly between groups.
The Quick Take
- What they studied: Can a program that includes fathers, starting in pregnancy and lasting through the baby’s first year, help prevent babies from gaining weight too quickly?
- Who participated: 227 mother-father pairs in a Massachusetts health care system, all speaking English or Spanish, enrolled during the second trimester of pregnancy. Data were analyzed for 194 babies.
- Key finding: Babies whose parents took part in the program had about half the odds of rapid weight gain compared to the control group at 6 months (adjusted odds ratio 0.42) and at 12 months (adjusted odds ratio 0.49). The chance of being overweight at 12 months was not significantly different between groups. Fathers in the program lost about 1 more BMI point than fathers in the control group at 6 months after birth.
- What it means for you: Involving both parents in early feeding and growth coaching may help some babies avoid rapid weight gain. This is a single study, so it should be seen as a promising step rather than a proven method. Parents should talk with their pediatrician about healthy feeding and growth.
The Research Details
This was a randomized controlled trial, which means participants were assigned to groups by chance. This is one of the most reliable ways to test whether a program actually causes a change. The study ran from 2020 to 2023 in a health care system in Massachusetts. Couples joined during the second trimester of pregnancy, and each mother and father pair was placed into either the First Heroes group or a control group.
The First Heroes group received three virtual health coaching sessions. They also had access to multimedia content, such as videos and online resources, from pregnancy through 12 months after birth. These materials focused on feeding, growth, and healthy habits for both parents. The control group received safety education, which gave them a comparison point without the program’s coaching on weight and health behaviors.
Researchers then tracked infant weight gain and the health of parents over time. They measured how often babies gained weight very quickly from birth to 6 months and from birth to 12 months. They also checked whether babies were overweight at 12 months, and they tracked mothers’ weight after birth and fathers’ BMI changes.
The trial used random assignment, a strong design for testing cause and effect. It included two languages, English and Spanish, which makes the findings relevant to a wider range of families. It was published in Pediatrics, a well-respected journal for child health research. However, the sample was fairly small, only 194 babies had outcome data, and the study took place in one health system, so results may not apply to every community. Some results were close to the line of no effect, which means they could change with a larger study.
What the Results Show
The main question was whether the program lowered the chance of rapid infant weight gain. At 6 months, babies in the First Heroes group had lower odds of rapid weight gain than babies in the control group (adjusted odds ratio 0.42, 95% confidence interval 0.19 to 0.93). This means the odds were less than half as high, after accounting for other factors that might affect results. The confidence interval stayed below 1, which suggests the difference was unlikely to be due to chance alone.
At 12 months, the benefit was still present but smaller. The adjusted odds ratio was 0.49 (95% confidence interval 0.25 to 0.99). The interval barely reached the line of no effect, so this finding is a bit less certain than the 6-month result. Researchers describe it as a meaningful signal that still needs confirmation in future work.
The program did not change the odds of infant overweight at 12 months. This is an important limit on the findings. Rapid weight gain in infancy can be a warning sign, but the trial did not show that the program prevented overweight itself within the first year.
Fathers who took part in the program had a larger drop in BMI at 6 months after birth. The adjusted difference was -1.08, with a 95% confidence interval of -2.06 to -0.11. BMI is a rough measure of body size based on height and weight. This suggests the program may have helped fathers as well as babies, which is a useful result because fathers have rarely been studied in early obesity prevention.
Maternal weight after birth did not differ significantly between the two groups. This means the program did not clearly change how much weight mothers kept after giving birth. The study also looked at parents’ health care and infant care habits, which are important because habits like feeding routines can shape growth over time.
Many earlier infant obesity prevention programs focused only on mothers or only on feeding advice from clinicians. This study adds evidence that involving fathers may be useful, which fits with research showing that fathers influence feeding, activity, and health habits in the home. The findings also support the idea that starting support during pregnancy and continuing into the first year may help. Still, because few trials have tested father-inclusive programs, this study should be viewed as an early step rather than a settled answer.
The study had a moderate number of participants, and only 194 of the 227 enrolled pairs contributed infant outcome data. Missing data can make results less certain. The program was tested in one health care system in Massachusetts, so results may differ in other places, with other cultures, or with families who have fewer resources. Some findings had confidence intervals that were close to showing no effect, so the results are promising but not definitive. The trial did not show a difference in infant overweight at 12 months, and it did not show a change in maternal weight. Researchers also noted that future studies should look at how to keep family-based prevention going throughout infancy, since the study does not show how long the benefits last beyond the first year.
The Bottom Line
Research shows that a father-inclusive coaching program during pregnancy and the first year may lower the odds of rapid infant weight gain at 6 and 12 months. Confidence is moderate because this is a single trial with a modest sample and results that were near the threshold of significance at 12 months. Families may benefit from involving both parents in feeding and growth conversations, but the program has not yet been shown to prevent overweight at age 1.
Expectant and new parents, especially fathers who are often left out of pediatric visits, may find this approach useful. Pediatricians, family health educators, and program designers who work on early childhood nutrition should also pay attention. Parents who are already working closely with a pediatrician may not need a new program, but they can still use this research as a reason to involve both caregivers. People looking for a medical treatment for a child with a known health condition should speak with a doctor rather than rely on this study alone.
Families would have to be involved from pregnancy through the first year to match the trial. Changes in rapid infant weight gain were seen by 6 months, with the benefit still present at 12 months. Changes in fathers’ BMI were measured at 6 months after birth. Because the trial did not show a lasting effect on overweight, realistic expectations should focus on healthy growth patterns and habits rather than guaranteed results on a specific timeline.
Frequently Asked Questions
Does including dads in infant feeding and growth coaching help prevent babies from gaining weight too fast?
A 2026 randomized trial of 227 mother-father pairs found that babies in a father-inclusive coaching program had about half the odds of rapid weight gain at 6 months (adjusted odds ratio 0.42). The benefit was still present at 12 months, though the result was less certain.
What is the First Heroes program for new parents?
First Heroes is a program that offers three virtual health coaching sessions and multimedia content for both parents. It runs from pregnancy through 12 months after birth and focuses on feeding, growth, and healthy habits for babies and parents.
Did the father-inclusive program prevent babies from becoming overweight by age one?
Not according to the 2026 trial. Although rapid infant weight gain was lower in the program group, the chance of infant overweight at 12 months did not differ significantly from the control group. Researchers say more studies are needed to confirm long-term benefits.
How much did fathers’ BMI change in a 2026 infant obesity prevention trial?
Fathers in the program had a greater BMI reduction at 6 months after birth, with an adjusted difference of -1.08 compared with fathers in the control group. The 95% confidence interval ran from -2.06 to -0.11, suggesting a modest but measurable effect.
Want to Apply This Research?
- Track each parent’s weekly feeding routine, such as the number of meals or bottles, and log the baby’s weight at each pediatric visit. Also record how often both parents took part in feeding or growth-related tasks each week. These measures are simple, specific, and match the habits the study looked at.
- Encourage both parents to share feeding tasks and set a weekly check-in to talk about the baby’s eating and growth. Use the app to create a shared feeding schedule and reminders for both caregivers so that fathers are included as active partners rather than observers.
- Over the first year, log infant weight from pediatric visits, feeding patterns, and parent participation in care tasks every month. Review trends with the baby’s doctor at each well-child visit. Add a short quarterly check for both parents to note their own healthy habits, since the study linked father involvement with changes in BMI.
This article summarizes a single randomized clinical trial and is for general information only. It is not medical advice. Results may not apply to every family, and infant growth depends on many factors. Parents should consult their pediatrician or family doctor before making changes to a baby’s feeding, nutrition, or health plan.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.