Pregnant moms who eat too much
may predispose their kids to be overweight
Overcoming the
'eating for two' myth
This study suggests that much of obesity is genetically predestined, however a connection between what happens to rats and what might happen to humans should be made with caution. The research is exciting and a first step to understanding how things work in humans, and it is plausible that events in fetal life can predispose to problems in the future.
Childhood obesity is a complex interplay of multiple factors including: activity, diet, genetics, and perhaps fetal exposures. Interestingly, genetics probably haven't changed all that much over the last 30 years, but clear detrimental changes in our lifestyles are likely the biggest contributors to the obesity problem.
Healthy eating
To many women, "eating for two" implies doubling your intake, but in fact, a pregnant women only needs to add the equivalent of one healthy snack, such as a glass of milk and a peanut butter sandwich on whole wheat, to her daily pre-pregnancy diet.
In gaining pregnancy weight, a well-balanced diet is ideal for all. Pregnant women are commonly deficient in two nutrients: folic acid and iron, as the fetus needs both in generous amounts for its development. Leafy greens that contain folic acid can be helpful and a prenatal vitamin can ensure sufficient folic acid. Iron can be obtained from meat as well as supplements. Women who follow diets that limit them to certain foods may be at risk for nutrient deficiencies that can be easily remedied. For example, vegetarians and vegans can be deficient in iron and vitamin B12 and supplementing their diet with a prenatal vitamin may be helpful.
Weight gain and risks
Pregnant women are encouraged to gain weight from a healthy diet during their pregnancies, but the specific amount should be tailored to the woman's height, build and preconception weight. In general, underweight moms are encouraged to gain 28 to 40 pounds, normal-weight moms should gain 25 to 30 pounds, overweight women 15 to 20 pounds and obese moms at least 15 pounds. Recent research, however, suggests that obese mothers can have healthy pregnancies with minimal or no weight gain during the pregnancy. Prenatal weight counseling is the best course of action to help determine the right amout of pregnancy weight to gain, especially for overweight and obese women.
In addition to concerns about childhood obesity, extra weight during pregnancy increases the risk of complications for both mother (higher rates of gestational diabetes, pre-eclampsia, and cesarean births) and child (increased risk of birth defects). Obese women are also predisposed to clots in their legs after delivery (deep vein thromboses) which are life threatening if not appropriately treated.
Obesity and diabetes
The predisposition to obesity runs in families and is likely a combination of lifestyle and genetics. Diabetes, especially type 2 diabetes, is thought to be a multi-faceted disease, with obesity and genetics being major risk factors. The challenge is figuring out the reasons a baby or child becomes obese or diabetic—is it genetics, or lifestyle, or both? Typically, children of obese parents learn how to eat from their parents, thereby perpetuating the cycle of obesity.
It's important for doctors and new mothers to discuss the risks of diabetes and obesity in children. Treatment is focused on what is modifiable (diet), lifestyle (exercise) with little help from medications. For newly diabetic women, drastic dietary and lifestyle changes help prevent hyperglycemia and help women have the healthiest pregnancies possible. If these changes can continue after pregnancy, the entire family may minimize their chances for obesity/diabetes-related problems.
Dr. Thung is an attending obstetrician/ gynecologist at Yale-New Haven Hospital, assistant professor in obstetrics and gynecology at Yale School of Medicine, and Director of Diabetes Management During Pregnancy with Yale Maternal Fetal Medicine.
September 2008
Every pregnant woman knows that she's eating for two. But if she overeats during the nine months she's carrying her baby, she could be creating serious weight-related problems for two, as well.
That's the latest theory among researchers trying to unravel the mystery of the childhood obesity epidemic. Though the three-decade rise in childhood obesity appears to have leveled off, researchers say the rate is still way too high: more than three times that of the 1970s. Doctors have long known that children's lifestyle habits—how much they eat and exercise—play a role in determining whether they gain too much weight. But the role of genetics has been less clear, says Thomas M. Badger, MD, of the USDA-Arkansas Children's Nutrition Center.
Some data seem pretty straightforward: bigger moms tend to give birth to bigger newborns, who often become heavier than normal children and prove to be at high risk for becoming obese adults. These correlations seem to suggest that much of obesity is genetically predestined.
Researchers noticed that kids were much more likely to have weight problems if they had an overweight mother.
Overweight women don't always produce overweight kids, but researchers noticed that kids were much more likely to have weight problems if they had an overweight mother. They wondered if excessive weight gain before or during pregnancy might directly affect the metabolic programming of the developing fetus.
To begin to answer this question, the Children's Nutrition Center completed a study, published earlier this year in the American Journal of Physiology, in which they overfed one group of normal-sized female rats before mating them with lean males. A second group of normal-sized females was fed a healthy diet before being mated with similarly sized males. After all the pups were born and weaned, both groups were fed a high-fat diet.
After 130 days on the diet, the offspring of the obese females were four times heavier and put on 60 percent more fat, even though the calorie intake of both groups was the same.
"They were programmed differently, so they responded differently," says Badger. "We think there's a high likelihood that something similar is happening in humans, in terms of programming kids to become overweight later in life."
However, that doesn't mean that everyone who is obese is metabolically programmed in utero, he says. The issue of why children become obese and overweight is very complex and there isn't a single explanation.
Women considering pregnancy should use these early results to motivate themselves to get into the best health possible before conceiving. "We'd recommend that women try to lose weight and increase their activity levels, and that their doctors should work with them on this prenatally," Badger says.
Other women's health resources
- Maternity Services, Yale-New Haven Hospital
- Women's Heart Program, Yale-New Haven Hospital
HealthLINK-Women's health archive