Racks of assorted snacks on display at Express Mart #4. Photo by Scott Ball.
Processed foods, generally low in micronutrients but rich in calories and carbohydrates, are often cheaper and more convenient than their plant-based counterparts. Credit: Scott Ball / San Antonio Report

Children whose mothers were obese during pregnancy are more likely to become overweight and suffer from cardiovascular disorders later in life because they develop a fatty liver, according to new research.

The study, published Thursday in the Journal of Physiology, revealed for the first time how fat accumulates in the liver, disturbing metabolic pathways as a fetus develops in an obese mother whose diet is high in sugar and fat. The research was conducted on baboons, the closest primate relative to humans.

Children born with a fatty liver are predisposed to chronic metabolic and cardiovascular diseases such as diabetes.

“If [a woman is] considering pregnancy, [she] should try to get fit,” Dr. Peter Nathanielsz, one of the lead investigators on the project, told the Rivard Report. “Maternal obesity is exploding through the westernized world and the developing world.”

Of women of reproductive age in the United States, “50 percent are overweight and 30 percent are actually obese,” Nathanielsz said.

In Bexar County, 32 percent of adults were obese in 2014, according to the San Antonio Metropolitan Health District; 39 percent of all adults in the County are considered overweight. People with a body mass index (BMI) of 25 are considered overweight while people are deemed obese if their BMI is 30 or higher.

Of low-income children ages 2-5 enrolled locally in the supplemental nutrition program for women, infants, and children (WIC) in 2015, 15.6 percent were obese.

“The rates of obesity are certainly increasing and are expected to increase,” said Anne Heine, community outreach manager with Healthy Start, a program working to improve maternal and child health in Bexar County. “As rates of obesity increase, the rates of diabetes” and other chronic diseases do too.

Heine noted that rate of Type 2 diabetes in children is “quite alarming,” and “if we continue on the track we are continuing on now, we will start seeing amputations in these children and young adults.”

The research was a collaboration between the Texas Biomedical Research Institute, UT Health San Antonio, Wake Forest Baptist Medical Center, the Indiana School of Medicine, and the University of Wyoming at Laramie, and took place at the Southwest National Primate Research Center in San Antonio.

In the study, researchers kept baboons on a high-fat, high-sugar diet until they were considered overweight, and then allowed them to breed. They then compared the fetal development of the overweight primates’ babies to those of normal-weight primates by examining liver cells to quantify the build-up of stored fat and sugar.

Some fat in the liver is typical, but when it increases above normal thresholds, a person is said to have a fatty liver. If the condition is dealt with early, it can be reversed. But if the liver continues to accumulate fat, the damage can lead to liver scarring and, later, liver cancer.

The researchers believe these complications likely explain why children of obese mothers live shorter lives with more health complications than offspring of normal-weight mothers.

Left: Fetus of a normal-weight baboon mother during pregnancy. Right: fetus of an obese, overweight baboon mother during pregnancy. The red stain represents fat. Credit: Courtesy / Texas Biomedical Research Center

While children cannot control their genetic predispositions, Nathanielsz said that “when a woman is pregnant, society is pregnant.”

“Decades of research show that the environment experienced in the uterus affects health throughout the lifetime,” he said.

A key part of that environment includes diet, said Nathanielsz, who put the responsibility on food manufacturers that mass-produce items that are generally low in micronutrients, but rich in calories and carbohydrates. These foods are often cheaper and more convenient than their plant-based counterparts and are heavily marketed to people of low income as being quick and affordable options.

“The incidence of obesity in San Antonio reflects the socioeconomic status of many people,” Nathanielsz said. “Yes, they could all get out and exercise a bit more, but they aren’t in a position to eat too well, so I don’t know what the answer is.”

Nathanielsz stressed that his research is not intended as an attack on mothers and what they choose to eat. “These are just the facts,” he said.

Heine, a registered dietitian, said people are more receptive now to suggested lifestyle changes to improve health and prevent disease compared to years past, and that initiatives that focus on healthy living instead of weight loss have contributed to a reduction in perceived stigma.

“Somewhere we have to reverse the obesity trend,” Nathanielsz said. “Most young men know more about what goes on under the hood of their car than what goes on in their bodies. I find that not a good formula for good health.”

Roseanna Garza reports on health and bioscience for the San Antonio Report.