Newswise — Grandparental child care is linked to nearly a 30% increase in childhood overweight and obesity risk, finds a new analysis from the Brown School at Washington University in St. Louis.

In a study, published online Jan. 22 in Childhood Obesity, researchers discovered that grandparents could impact their grandchildren’s waistline in various ways, such as influencing their daily diet and physical activity, as well shaping their grandchildren’s perceptions on what represents a healthy lifestyle.

“The past decades have witnessed a rapid increase in life expectancy. Older adults are not only living longer but also being healthier and more productive than ever before,” said Ruopeng An, assistant professor at the Brown School and lead author. “For many, grandparenting is the highlight of their later years, and we observe grandparental care to be more common over time in the U.S. and other parts of the world.”

When the Pew Research Center surveyed older people regarding their most valuable experience during aging, 19% of the men and 31% of the women referred to spending time with their grandchildren, An said. Some grandparents offer intensive care for their grandchildren while others offer intermittent assistance. In total, nearly 40% offer some grandchild care, and nearly a third assist with errands, housework or home repairs in the U.S., he said.

“Grandparents’ influence on their grandchildren’s growth and development can be profound,” An said. “Through offering wisdom, teaching traditions, providing guidance and making memories, grandparents are often able to leave behind a legacy that their grandchildren will cherish and benefit lifelong. However, some negative influences from grandparental care may also be present and cannot be overlooked.”

An and his co-authors — from the University of Michigan, Shanghai University and Overseas Chinese College in Beijing — conducted a comprehensive review and data analysis on the scientific literature that studied the relationship between grandparental care and childhood obesity.

In An’s paper, “Influence of Grandparental Child Care on Childhood Obesity: A Systematic Review and Meta-Analysis, he and his co-authors reviewed a total of 23 studies. Eight studies were conducted in China, five in Japan, three in the United Kingdom, two in the U.S. and one each in five other countries. Twelve studies focused on grandparents’ roles as a main caregiver in the family and seven on grandparents’ co-residence.

“Affluence and being well fed is valued and desirable to many grandparents as they had experienced hunger and poverty in their youth, which they may pass on to their grandchildren, who, to the opposite, are fighting against a world of food swamps and ever-expanding portion size,” An said.

“The notion of ‘the bigger the healthier’ is still relevant,” he said. “Some grandparents may perceive heavier body weight in children as a sign of being healthy. As such, some children are urged to eat larger and more frequent meals. Some grandparents may provide children with sweets and fried food as a way to show love and kindness. In fact, in some cultures, grandparents may also be more likely to excuse children from doing household chores, a key form of physical activity.”

To his surprise, An said, the positive association between grandparental childcare and childhood overweight and obesity was not found to differ between countries.

“Grandparental care is long known to have deep cultural roots,” he said. “Based on Ziarat Hossain’s research, grandparents in western countries provide care when they are needed and called upon, known as the ‘non-interference’ approach.

“On the other hand, grandparents in Asian and African countries are so active and direct in their grandchild’s lives that they sometimes are considered the ‘two additional sets of parents.’ What underlines the lack of difference in the influence of grandparental care on childhood obesity? No concrete conclusions can be drawn at this moment and future research is needed.”

Although meta-analysis identified a positive association between grandparental child care and childhood overweight and obesity, grandparental child care was not associated with children’s Body Mass Index (BMI) z-scores — the accepted measure for childhood weight adjusted for age and sex. (A z-score gives an idea of how far from the mean a data point is.)

“This is likely due to lack of statistical power given that only four studies included in this review analyzed children’s BMI z-scores. It is also possible that the relationship between grandparental child care and childhood obesity is more complicated than a simple linear relationship,” An said.

“The impact of grandparenting is multilayered and complex,” he said. “Through research, we hope to provide scientific support for both grandparents and their grandchildren to make the best out of their precious, bonding relationship.”

Journal Link: Childhood Obesity