Baby Weight Gain Linked to Type 1 Diabetes

A new study shows that the risk for type 1 diabetes could begin in the first year of life—and how much weight your baby gains in the first 12 months could be a sign.

Baby Weight Gain Linked to Type 1 Diabetes iofoto/Shutterstock

Everyone loves a chunky baby, and chubby rolls are often looked at as a sign of a well-fed, and well-developing, child. But, it turns out that the more an infant gains in the first year, the greater the risk of type 1 diabetes later on in childhood, according to a new study published in the journal JAMA Pediatrics.

Unknown risk factors

Researchers looked at two study groups that included over 99,000 children from Norway and Denmark, who were followed up to 13 years of age. "We found that the higher the infant weight gain [weight at 12 months minus birth weight], the higher the subsequent risk of type 1 diabetes," senior study author Lars C. Stene, Ph.D., a researcher at the Norwegian Institute of Public Health in Oslo, tells Fit Pregnancy. "There seemed to be a gradual increase in risk of type 1 diabetes associated with increasing weight gain." The average weight gain in their first year was just over 13 pounds, with the more weight gained, the greater the risk—regardless of the increase in the babies' length.

The study authors say their research is the first to show that weight increase in baby's first year is associated with type 1 diabetes, a disease whose cause is still a mystery. Unlike type 2, which usually begins later in life and is linked with physical inactivity and obesity, type 1 is an autoimmune disease also called "juvenile diabetes" because it starts in childhood. The immune system starts attacking the cells that allow the pancreas to produce insulin, which the body needs to manage blood sugar.

But, Stene says that weight gain is actually not a symptom or a cause of type 1, but rather a marker that warrants further study. "Weight gain is highly unlikely to be a symptom of type 1 diabetes—if anything, weight reduction is a common symptom occurring around onset of the disease," which is often around puberty, he says. "Regarding weight gain as a cause of type 1 diabetes, we do not believe it is the pounds of weight gain that directly influences the risk of type 1 diabetes. It is more likely to be explained by some other factor."

Is prevention possible?

Type 1 is believed to be caused by a combination of genetic and environmental factors, but it's not clear exactly how it develops. "We know that most children with type 1 diabetes carry a combination of genes from both parents that influence their degree of susceptibility to disease," Stene says. "The changing incidence of type 1 diabetes observed in most countries over the past two to three generations suggest there must be something in the environment, but we do not yet know why or how. Other theories involve infections and the composition of microbes [bacteria] in our gut. We hope future studies may be able to investigate this further."

Scientists theorize that certain viruses may trigger an autoimmune response leading to type 1 diabetes in those who are genetically susceptible. Infant nutrition could also play a role, with some studies showing that breastfeeding may reduce the risk of type 1, while early exposure to cow's milk and cereal proteins may increase it. This could be because of the possible link between breastfeeding, the development of gut bacteria and improved immune function—so if babies are less likely to get viruses, they may be less likely to trigger the response that leads to type 1 diabetes. But, more research is needed before doctors can say for certain. "There is currently nothing we can do to prevent this disease with documented effect," Stene says.

What to look out for

In the meantime, parents should talk to their pediatrician about where their babies' weight falls on the World Health Organization's growth chart, keeping in mind the different rates of growth for breastfed and formula-fed infants. Generally, babies should gain 1-2 pounds per month for the first six months, and then about 1 pound from six months to one year. "While our results points researches towards early life and factors related to infant weight gain, it is too early to give advice to modify weight gain for this purpose alone," Stene says, recommending that parents stick to the existing guidelines for infant feeding to avoid excessive weight gain.

As your child grows, Stene says to look out for certain red flags for type 1, such as weight loss, excess urination, thirst and fatigue. "The extent of these symptoms varies between children and is not always obvious," he says. "Depending on the awareness in affected families, symptoms typically occur a few weeks or in some instances even months before the diagnosis is finally established by a doctor."