Maternal Obesity Before Pregnancy Tied to 64% Higher Childhood Obesity Risk
Key Takeaways:
- Children whose mothers had obesity before pregnancy were 64% more likely to be affected by overweight or obesity by age 3.
- Gaining excess weight during pregnancy – common among about 41% of mothers studied – was linked to a 39% higher risk.
- Maternal weight factors mattered at different stages, and the links varied between Hispanic and non-Hispanic families.
The roots of childhood obesity may begin in the womb
New research led by the George Mason University College of Public Health has found that children whose mothers began pregnancy with obesity were 64% more likely to be affected by overweight or obesity by age 3. Excessive weight gain during pregnancy was associated with a 39% increase in that risk.
“Our findings suggest that childhood obesity risk may not develop in a single, uniform way, but maternal health before and during pregnancy may play a larger role than many people realize,” said study lead author Hua Min, associate professor in the Department of Health Administration and Policy.
Timing appears to matter
Different pregnancy-related weight factors appeared to matter at different stages. Excess weight gain during pregnancy was more closely linked to infant weight, while maternal obesity was more strongly associated with weight later in toddlerhood. Researchers also found that excess weight gain during pregnancy was common, affecting about four in 10 mothers in the study.
A large, ethnically diverse US study
Published in the International Journal of Obesity, the research is among the largest and most ethnically diverse longitudinal studies in the United States to examine how maternal weight may influence obesity risk in early childhood. Researchers tracked nearly 3,000 mother-child pairs, drawing on data from a Northern Virginia birth cohort taking part in the National Institutes of Health’s Environmental influences on Child Health Outcomes (ECHO) Program.
The George Mason research team included Michael S. Bloom of the Department of Global and Community Health, along with Grace Lawrence, Alma Fuller and Kathi C. Huddleston of the School of Nursing.
Why this matters
Childhood obesity remains one of the most pressing health challenges in the United States. The study notes that nearly 90% of children with obesity at age 3 will continue to be affected by overweight or obesity into early adulthood. Those early patterns can carry long-term consequences, increasing the risk of diabetes, cardiovascular disease and other chronic health problems.
Researchers say the findings reinforce the importance of maternal health before and during pregnancy – not just for pregnancy outcomes, but also for a child’s long-term health trajectory. The findings also suggest that obesity risk may develop differently across populations, with patterns varying among demographic groups.
Study details
The findings were based on the First Thousand Days of Life Study, a Northern Virginia birth cohort taking part in the ECHO Program, which examines how early-life experiences affect child health. George Mason was selected as an ECHO research site in 2019.
Researchers enrolled 2,899 mother-child pairs in Northern Virginia between 2012 and 2019, following families from pregnancy through to age 3.
Key findings
The strongest signal came from maternal weight before conception. Children whose mothers had obesity before pregnancy were 64% more likely to be affected by overweight or obesity by age 3, and the risk rose incrementally with weight: for every one-point increase in maternal pre-pregnancy body mass index (BMI), the likelihood of childhood overweight or obesity climbed by about 4%.
Weight gain during pregnancy carried its own, separate risk. Children whose mothers gained excessive weight while pregnant were about 39% more likely to be affected by overweight or obesity by age 3, and roughly 41% of mothers in the study gained more than national guidelines recommend. Notably, the two factors seemed to act at different points in early life: excess weight gain during pregnancy showed stronger links to higher weight in infancy, whereas maternal weight before pregnancy became more strongly associated with higher child weight later in early childhood. The associations also differed between Hispanic and non-Hispanic families, suggesting that obesity risk may develop differently across populations.
Looking ahead
Taken together, the findings point to the period before and during pregnancy as a meaningful window for a child’s long-term health, rather than a single moment or cause. Because the maternal weight factors appeared to matter at different stages, and because the associations varied between demographic groups, the researchers suggest that efforts to understand and address childhood obesity may need to account for how risk builds over time and how it differs across populations.
Source: George Mason University
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New Research Shows Obesity May Reshape How Breast Cancer Spreads
Key Takeaways:
- Obesity may alter how early, non-invasive breast lesions progress into invasive cancer, a University of Oklahoma study suggests.
- In women with obesity, progression was linked to inflammation, immune cell activity, metabolic changes and raised levels of the enzyme SULF2 – not the rapid cell division seen in women without obesity.
- The findings could improve risk prediction for women with DCIS and help reduce overtreatment.
A different route to invasive disease
Obesity may change how early-stage breast cancer becomes invasive, according to a study by University of Oklahoma researchers published in The American Journal of Pathology.
Obesity is already recognised as a risk factor for invasive breast cancer, but researchers have not fully understood how it helps early, non-invasive breast lesions develop into invasive cancer. A clearer picture of this process could strengthen physicians’ ability to predict and treat the disease.
In the study, breast cancers in women without obesity displayed the typical signs of turning invasive, including rapid cell division and an increased ability to invade neighbouring tissue. In women with obesity, however, the researchers identified a different set of biological changes that appeared to help the cancer become invasive.
The cancer environment became more inflamed, with the arrival of immune cells that advanced the growth of the tumour. The tumour cells also appeared better able to survive under stress, and there were changes in cellular metabolism – how the cells use nutrients for energy.
“This could be why women with obesity are at higher risk for invasive breast cancer,” said Bethany Hannafon, Ph.D., co-lead author of the study and an assistant professor in the Department of Obstetrics and Gynecology at the OU College of Medicine. “The changes that the cancer cells are undergoing are allowing them to survive and thrive.”
A cooperative cancer “neighbourhood”
The researchers also found differences in the “neighbourhood” of cells and tissues surrounding the cancer. Epithelial cells, where the tumour originally develops, co-opt other cells around them to create an environment that is even more conducive to cancer growth.
“In women with obesity, there is cooperation between all the cell types, not just the cancer cells, which helps an early pre-cancer to become an invasive breast cancer,” said co-lead author Elizabeth Wellberg, Ph.D., assistant professor in the Department of Pathology at the OU College of Medicine. “That may be an area of future study – can a drug or intervention that targets only one cell type interrupt the whole network of progression toward invasive cancer?”
The role of the enzyme SULF2
The research team additionally discovered higher levels of an enzyme called Sulfatase 2 (SULF2) in the tumour cells of women with obesity, suggesting that it may play an important part in cancer progression. SULF2 will be a further focus of future studies.
Why better DCIS risk prediction matters
Understanding what causes early, non-invasive tumours – known as ductal carcinoma in situ, or DCIS – to become invasive is important because not all women will go on to develop invasive cancer, yet they currently receive the same treatment.
“In women diagnosed with DCIS, about half will later develop invasive ductal carcinoma (IDC) that spreads into surrounding breast tissue. But we currently have no way of determining which women are most at risk. As a result, many women with DCIS receive the same treatments used for IDC, including surgery, radiation and sometimes hormone therapy. Overtreatment is a major concern, but if we had better ways of determining risk, unnecessary treatments could potentially be reduced,” Hannafon said.
While breast cancer survival rates have improved over the past two decades, the number of women diagnosed with invasive breast cancer has not declined – underscoring the need for better ways to predict and prevent disease progression.
A growing public health concern
The rising prevalence of obesity gives the findings added weight.
“Obesity is on the rise – 50% of Americans are expected to be obese by 2030,” said the paper’s first author, Cole Hladik, Ph.D., who worked in Hannafon’s lab while earning his doctorate. “That statistic further highlights the importance of considering a patient’s metabolic health alongside the biology of the tumor itself.”
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Breastfeeding for Three Months or More Linked to Lower Long-Term Weight Gain in Women
Key Takeaways:
- Women who breastfeed for at least three months may gain significantly less weight later in life, with differences observed decades after childbirth.
- The strongest long-term effect is seen in women who had overweight or obesity before pregnancy.
- Breastfeeding appears to influence energy balance, although individual responses vary and support remains essential.
Long-term impact of breastfeeding on weight
Breastfeeding has long been associated with short-term postpartum weight changes, but new research suggests its effects may extend much further. A study conducted by researchers at the University of Oslo indicates that women who breastfeed for at least three months may experience lower weight gain even decades later.
According to the findings, women gained up to 6.5 kilograms less on average later in life if they breastfed for a minimum of three months. This extends the understanding of breastfeeding beyond its immediate postpartum benefits, highlighting its potential role in long-term weight trajectories.
Previous research has largely focused on weight changes in the first one to two years after childbirth. In contrast, this study followed women for up to 50 years after they had stopped breastfeeding, offering a rare insight into lifelong health patterns. The findings are expected to inform further research into maternal cardiovascular risk.
Large-scale study provides robust data
The analysis drew on data from the Women and Health Study, which includes more than 170,000 women in Norway. The results were published in the American Journal of Clinical Nutrition.
This large cohort allowed researchers to examine how breastfeeding duration relates to weight development across different groups of women, while accounting for factors such as education, physical activity, and smoking.
Strongest effect seen in women with overweight
The most pronounced differences were observed among women who had overweight or obesity in early adulthood, prior to pregnancy.
“We compared women in this group who were otherwise similar in terms of education level, physical activity and smoking. We then found that those who breastfed for three to 15 months gained on average up to 6.5 kilos less from young adulthood to middle age, compared with those who breastfed little,” says Thorbjørn Brun Skammelsrud.
Skammelsrud is completing his doctoral research at the Department of Nutrition, Institute of Basic Medical Sciences at the University of Oslo.
More modest differences in women with normal weight
Among women who had a normal weight in early adulthood, the long-term effect of breastfeeding was still present but less pronounced. Those who breastfed for three to 15 months gained up to 3 kilograms less compared with those who breastfed for shorter periods.
For women who had been underweight before pregnancy, breastfeeding appeared to have little influence on long-term weight outcomes.
Biological mechanisms and individual variation
The study also highlights the complex relationship between breastfeeding and energy balance.
“Breastfeeding increases energy expenditure, so in theory breastfeeding should contribute to weight loss. But precisely because energy expenditure increases, some women will also experience increased appetite when they are breastfeeding,” Skammelsrud explains.
This means that while breastfeeding may support weight regulation at a population level, individual experiences can differ significantly.
Implications for public health
The study included women who had children as early as the 1940s, although the association between breastfeeding and lower weight was strongest among those who gave birth after 1980. This group is considered more representative of current maternal behaviours, particularly in terms of diet and breastfeeding practices.
In Norway, national guidance generally recommends partial breastfeeding for one year or longer, provided both mother and infant are comfortable. Breastfeeding rates in Norway are relatively high compared with many other countries.
“This is positive for public health. At the same time, the study shows that some women may need extra follow-up after giving birth, particularly those with overweight or obesity,” Skammelsrud says.
Supporting women who choose to breastfeed
The findings reinforce the importance of enabling and supporting breastfeeding where desired.
“In this study, we see that breastfeeding for at least three months has a positive effect on women’s weight later in life. It is therefore important that breastfeeding is facilitated, and that women who wish to breastfeed are offered qualified support,” the researcher says.
Ensuring access to appropriate guidance and support may help maximise both short-term and long-term health outcomes for women.
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Combination of Hormone Therapy and Tirzepatide Linked to Greater Weight Loss After Menopause, Study Finds
Key Takeaways:
- Postmenopausal women using menopausal hormone therapy alongside tirzepatide lost around 35% more weight than those using tirzepatide alone in an observational study.
- The findings suggest a potential interaction between hormone therapy and GLP-1-based obesity medications, although causality cannot be confirmed.
- Researchers say the results warrant randomised clinical trials to explore mechanisms and broader cardiometabolic effects.
Weight management challenges after menopause
A new study led by researchers at Mayo Clinic suggests that combining menopausal hormone therapy with tirzepatide may be associated with substantially greater weight loss in postmenopausal women. The findings, published in The Lancet Obstetrics, Gynaecology, & Women’s Health, indicate that women receiving hormone therapy lost around 35% more weight while taking tirzepatide compared with those treated with tirzepatide alone.
Tirzepatide is approved by the US Food and Drug Administration for the treatment of overweight and obesity. The study’s authors say the results could expand treatment options for the many women who experience weight gain and related health risks following menopause.
Menopause is associated with accelerated age-related weight gain and a higher likelihood of developing overweight or obesity, both of which are major risk factors for cardiovascular disease, type 2 diabetes, and other long-term conditions. In addition to changes in body weight, the decline in oestrogen levels that occurs during menopause is also linked to physiological changes that may independently increase cardiovascular risk.
“This study provides important insights for developing more effective and personalized strategies for managing cardiometabolic risk in postmenopausal women,” says Regina Castaneda, MD, postdoctoral research fellow at Mayo Clinic and first author of the study.
Hormone therapy and obesity treatments
Menopausal hormone therapy is considered the most effective first-line treatment for common menopausal symptoms, such as hot flashes and night sweats, which affect up to 75% of postmenopausal women. Despite its widespread use, evidence on how hormone therapy may interact with pharmacological obesity treatments remains limited.
Previous research has suggested that postmenopausal women using hormone therapy may experience greater weight loss when treated with semaglutide, another GLP-1-based medication for obesity. However, until now, no studies had specifically examined whether hormone therapy might influence outcomes in people treated with tirzepatide.
To explore this question, Dr Castaneda and colleagues reviewed data from 120 participants with overweight or obesity who had received tirzepatide for weight management for at least 12 months. Outcomes among participants who were also using menopausal hormone therapy were compared with those of participants with similar characteristics who were not receiving hormone therapy.
Findings and limitations
According to the researchers, women using both treatments experienced markedly greater weight loss than those using tirzepatide alone.
“In this observational study, women who used menopausal hormone therapy lost about 35% more weight than women taking tirzepatide alone. Because this was not a randomized trial, we cannot say hormone therapy caused additional weight loss,” says Maria Daniela Hurtado Andrade, MD, PhD, endocrinologist at Mayo Clinic and senior author of the study.
She adds that other factors may partly explain the difference observed between the groups.
“It is possible that women using hormone therapy were already engaged in healthier behaviors, or that menopause symptom relief improved sleep and quality of life, making it easier to stay engaged with dietary and physical activity changes.”
The authors emphasise that, as an observational analysis, the study cannot establish a causal relationship between hormone therapy and enhanced weight loss. Nonetheless, they argue that the size of the observed difference is clinically meaningful.
Possible biological synergy
Dr Castaneda notes that the findings align with emerging preclinical evidence suggesting a biological interaction between oestrogen and GLP-1-based therapies.
“The magnitude of this difference warrants future studies that could help clarify how GLP-1-based obesity medications and menopausal hormone therapy may interact. Interestingly, preclinical data suggest a potential synergy, with estrogen appearing to enhance the appetite-suppressing effects of GLP-1,” she says.
Such a mechanism could help explain why women receiving hormone therapy appeared to derive additional benefit from tirzepatide in this study.
Next steps for research
The research team plans to build on these findings through more rigorous study designs.
“Next, we plan to test these observations in a randomized clinical trial and determine if benefits extend beyond weight loss – specifically, whether hormone therapy also enhances the effects of these medications on cardiometabolic measures,” says Dr Hurtado Andrade. “If confirmed, this work could speed the development and adoption of new, evidence-based strategies to reduce this risk for millions of postmenopausal women navigating this life stage.”
The study was funded by the Mayo Clinic Center for Women’s Health Research. The full publication includes a complete list of authors, disclosures, and funding sources.
CCH insight:
This is an interesting study, but as the authors state, no conclusions can be drawn from the findings. But it does raise many questions about the possible potential synergistic effects of oestrogen and GLP-1 therapy. Establishing whether cardiometabolic benefits of GLP-1 medications are amplified, as well as weight loss, should be a priority.
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