By Mark Couch
Lynn Barbour, MD, and Teri Hernandez, PhD, RN
(December 2017) In the late 1990s, Teri Hernandez was a cardiovascular nurse in the land of deep-fried Thanksgiving turkeys.
for patients at Baylor University Medical Center in Dallas, she saw how
their health had been compromised by a lifelong habit of eating food
that had clogged their arteries and caused other problems.
taking care of people who were very sick with cardiovascular disease
either after their surgery or at their death – through the whole
trajectory – and I saw how they ate,” Hernandez said.
set out to translate that experience into one that improves the quality
of life from the start and today she’s a researcher on the University of
Colorado Anschutz Medical Campus, challenging the conventional wisdom
of a frequently recommended low-carbohydrate diet for pregnant women
with gestational diabetes.
“These women are oftentimes broadsided
when they go through the first two trimesters of pregnancy and then they
get a diagnosis of gestational diabetes,” Hernandez said. “They
thought everything was going OK and suddenly they have a high-risk
Hernandez, PhD, RN, associate professor of
medicine and nursing, and research partner Linda Barbour, MD, professor
of medicine and obstetrics, are evaluating the health consequences of
diet options that may provide a better alternative for pregnant women
who develop gestational diabetes.
“They’re put on a diet and
they’re told not to eat carbs, or to restrict them, because they will
make their baby big,” Hernandez said. “No bread, for example. And then
for the first time in their lives they have to check their blood sugars
four times a day.
“So you can see why they felt like prisoners to
this nutrition plan, which was meant to control their sugars – and which
does control sugars, at least to some degree. But instead what we
noticed is that they were eating high-fat diets to replace the carbs,
kind of like those of my sick cardiovascular patients.”
those moms-to-be weren’t consuming the deep-fried turkeys that Hernandez
noticed during her time in Texas. But, still, the diets of these
pregnant women were filled with similar fatty foods.
being told, ‘Don’t eat your cereal, but go ahead and eat sausage and
eggs and bacon because it will not cause your sugars to go as high,’”
Barbour said. “But that’s just a high-fat diet without the lower
calories that is characteristic of the Atkins diet. Teri really questioned whether this diet made sense.”
turns out that the sausage-without-the-biscuit, bacon-without-the-bun
diet wasn’t all that healthy either. Instead, such a high-fat diet may
have been contributing to the problem it was intended to fix.
have been doing research showing that obese women have higher glucose
levels than normal weight women, and they also have higher
triglycerides,” Barbour said. “And triglycerides – although it’s really
not been appreciated very much – are a very powerful fuel for babies to
put on extra fat because it’s actually easier biochemically to make fat
from fat than it is to make fat from glucose.”
articles, Barbour and Hernandez have demonstrated that obese women have
higher glucoses as well as higher triglycerides and free fatty acids.
Their research demonstrates that higher triglycerides and free fatty
acids might be even more important in causing babies to develop excess
fat. Babies born with excess fat face greater lifelong metabolic health
“When born with excess fat, their risk for diagnosis of
childhood diabetes is even higher,” Barbour said. “We’ve been very
interested in the intrauterine environment and how that can place
mothers at risk for having a baby at high risk for childhood obesity,
metabolic disease, diabetes.”
So, to reduce the chances of a
too-big baby and the resulting health risks, Hernandez and Barbour are
studying a diet that calls for a balance of complex carbohydrates and
“The premise of the CHOICE diet is that a carb is not a
carb,” Hernandez said. “Maybe choosing healthier varieties of
carbohydrate, such as whole grains, legumes, beans, and complex carbs,
will allow women not to have to cut carbs to the point that they feel
miserable and feel like they can’t eat any at all. When they cut carbs,
they have very few safe foods at that point. And they’re hungry.”
unique feature of their study is that all meals are provided to the
mothers. An initial study using that approach provided encouraging
results. Pregnant women eating complex carbohydrates had very similar
glucose patterns when wearing 24-hour continuous glucose monitors that
sample their glucoses every five minutes.
In addition, they had
“better insulin action,” Hernandez said, meaning that they were less
insulin-resistant than women on the carb-restricted conventional diet.
The mothers also had lower free fatty acids, which arise from breakdown
products of triglycerides, and the babies born to mothers on the CHOICE
diet had a lower percentage of body fat.
“That was enough
provocative pilot data that we were able to get a much larger NIH-funded
R01 study for five years,” Hernandez said, “and that’s what we’re doing
“We hope that by providing all meals to the mothers
in our study that we can finally determine the ideal diet for mothers
with gestational diabetes, and perhaps for all pregnant women, to
optimize both maternal and baby outcomes.”