New evidence suggests fathers may influence their children's obesity risk through changes in sperm, lifestyle habits, parenting behaviors, and family environments, prompting researchers to call for father-inclusive strategies that begin even before conception.
Study: The Role of Fathers in the Intergenerational Transmission of Obesity. Image credit: Creativa Images/Shutterstock.com
A recent review published in the journal Current Obesity Reports suggests that fathers influence the risk of obesity in their children through multiple interacting pathways beginning before conception. The findings suggest that efforts to prevent and research child obesity should focus on fathers as well as mothers.
Expanding obesity research beyond maternal factors
Childhood obesity continues to rise in the United States alongside increasing rates of overweight and obesity among adults. Current projections suggest that more than 250 million Americans could be overweight or obese by 2050.
Research shows that children are more likely to develop obesity when one or both parents are affected, particularly when both parents have obesity. This relationship highlights the complex interplay of genetic, biological, behavioral, and environmental factors that contribute to obesity risk across generations.
According to the Developmental Origins of Health and Disease (DOHaD), the periconceptional period is critical in laying the groundwork for future long-term outcomes, including cardiometabolic disease, through exposure to environmental factors. Maternal nutrition, obesity, and metabolism have been studied in detail because they shape the fetal environment.
More recently, the Paternal Origins of Health and Disease (POHaD) framework has been brought under the DOHaD umbrella. The current review examined biological, psychological, and behavioral pathways through which paternal factors influence children’s health, though not in isolation from family dynamics and other environmental and social factors. The authors emphasize that paternal influences operate alongside maternal and broader family influences.
Obesity alters sperm and offspring metabolism
About 40% to 70% of obesity is heritable via hundreds of obesity-linked variants. Obesity in fathers affects the metabolic health of offspring by several routes.
Paternal obesity influences sperm quality, reduces sperm concentration and motility, and increases the rate of sperm DNA fragmentation. These changes are linked to the adverse effects of obesity on paternal metabolism. These sperm abnormalities are reflected in a 30% to 66% increase in the risk of infertility among men with obesity, and increase the risk of pregnancy loss unrelated to maternal factors.
Obesity is linked to metabolic dysregulation via disrupted endocrine regulation of sperm production; testicular and systemic inflammation; and epigenetic alterations in sperm. Sperm cells are continuously produced and mature for months before conception, allowing a wide window of environmental exposure.
Alterations in the epigenetic profile are heritable and affect gene expression in the developing embryo across pathways linked to appetite regulation, insulin signaling, and fat metabolism. In animals, a high-fat diet in the father is associated with obesity-related changes in the offspring. However, while animal studies provide strong evidence for these mechanisms, the biological pathways in humans remain incompletely understood.
Notably, some obesity-associated epigenetic changes in sperm are reversible by lifestyle modifications prior to conception.
Fathers' habits help shape children's behaviors
Fatherhood tends to be associated with weight gain in fathers and changes in multiple health behaviors, for better or worse. A healthy preconceptional paternal diet is associated with improved sperm quality and concentration, irrespective of age and body mass index (BMI). The converse is true with a poor-quality diet.
The quality of a father’s diet, his physical activity habits, feeding practices, and parenting style directly and indirectly, through role modeling, influence the child’s eating and activity levels. This is also the case with physical activity and sedentary habits in the father.
Positive modeling, monitoring, and shared family meals are associated with better diet quality and healthier food choices in children.
Neighborhood and food access shape outcomes
The risk of paternal obesity is influenced by multiple other factors, including income, education, and neighborhood type.
Residential neighborhood affects children’s diet, directly via food access and indirectly via its association with food security, socioeconomic status, and the father’s mental health. Food insecurity is linked to a higher consumption of high-calorie foods and an increased risk of obesity. Similarly, limited access to safe recreational spaces limits physical activity and increases the risk of obesity.
Such factors operate at the family level, affecting multiple areas, ranging from the father’s physiology and parenting style to the child’s developmental environment. These interact to compound the increase in obesity risk across generations.
Mental health is particularly important. If the father is depressed, he is less likely to have an engaged or positive parenting style or value preventive healthcare for himself or his family. This worsens children's eating and sleep behaviors and increases obesity risk. Children living with a parent experiencing depression are at increased risk of adverse childhood experiences (ACEs), which may impact their long-term obesity risk.
Fathers may influence obesity risk from the start
The authors conclude that fathers play an important role in how obesity risk is transmitted across generations. This begins preconceptionally and continues through childhood. However, the authors note that much of the current evidence is observational, and additional human research is needed to better understand the biological mechanisms linking paternal health and offspring obesity risk.
They suggest that obesity prevention strategies should include preconceptional counseling addressing fathers as well as mothers; perinatal education targeting both parents; including fathers in obesity prevention methods; workplace policies that promote paternal involvement in the child’s care; and placing greater importance on research that examines the father’s role in obesity transmission across generations.
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