Slower calorie burn in pregnancy may mean more retained baby weight in obese black moms

April 22, 2018, American Physiological Society
Credit: CC0 Public Domain

Differences in the way women with obesity burn calories during pregnancy may be a contributor to long-term postpartum weight retention in black moms, according to researchers in Baton Rouge, La. Their new study shows that despite similar levels of food intake and activity levels—and a higher proportion of fat-free mass—obese black women burned fewer calories than their white counterparts. The findings, which suggest a need for more individualized pregnancy weight gain recommendations for obese women, will be presented today at the APS annual meeting at Experimental Biology 2018 in San Diego.

Women with obesity—defined as a body mass index of 30 or above at the start of pregnancy—are at increased risk for gaining too much during their pregnancy and retaining weight after they give birth. In many cases, retained "baby weight" eventually becomes regular weight that may further exacerbate preexisting obesity and related health problems.

Researchers at Louisiana State University's Pennington Biomedical Research Center and the Woman's Hospital in Baton Rouge measured expenditure, body composition and markers of metabolic health in 66 black and white pregnant with obesity.

The women were comparable in age (average age 27), BMI (approximately 37) and body fat percentage (approximately 45 percent). The black women were heavier and had a higher amount of fat-free mass (muscle, bone, skin, etc.), which suggest that they had a higher metabolism and would burn more calories. While the black women ate roughly 300 fewer calories per day, the composition of their diet and daily energy expenditure was similar to their white counterparts. However, when the researchers compared energy expenditure—assuming that body mass was the same in black and white women—they found that black women burned roughly 230 fewer calories during the day and 80 fewer calories while sleeping.

The researchers think that the findings may be partly due to the composition of the fat-free mass in black women. Previous research has shown that while have a higher proportion of calorie-burning muscle, they may have a smaller liver and kidney, two organs that expend more energy than muscle. "Another hypothesis is that African-Americans are more efficient in the use of energy during activity. This can be compared to a more fuel-efficient car, which consumes less gas for the same performance," lead researcher Jasper Most, PhD, of Pennington Biomedical, explained.

Clinicians commonly recommend that pregnant women add an additional 300 to 500 calories per day and that aim to between 11 and 20 pounds during the course of a normal pregnancy. These findings could have implications on current non-race-specific calorie intake recommendations for pregnant women.

"The recommendations for pregnancy are based on weight gain in relation to pregnancy outcomes such as healthy fetal size and in the absence of pregnancy complications. Therefore, our findings cannot immediately contribute to suggestions on healthy weight gain," Most said.

"However, our findings might indeed influence the recommendations for energy intake during pregnancy. The estimated energy-intake requirements to achieve healthy weight gain are the sum of energy that a pregnant woman expends and what she stores (in fat tissue and for fetal growth, for example).

"We show that the is less in African-American women and therefore energy intake requirements should probably be smaller for African-American women. We estimate if African-American women eat the amount of calories recommended for , they would likely gain more weight in pregnancy (up to 7 kg/15 lbs. more) than what is considered healthy," Most said.

Jasper Most, PhD, of Pennington Biomedical, will present the poster "Propensity for excess gestational weight gain in African-American women may be explained by hypometabolic factors in early " on Sunday, April 22, in the Exhibit Hall of the San Diego Convention Center.

Explore further: Race, pre-pregnancy BMI may help predict maternal weight gain

Related Stories

Race, pre-pregnancy BMI may help predict maternal weight gain

March 18, 2018
Race and pre-pregnancy body mass index (BMI) both affect leptin and adiponectin levels, and leptin levels in mid-pregnancy may be an important predictor of weight gain during pregnancy, new research suggests. The results ...

Only 25 percent of women receive appropriate advice on pregnancy weight gain

February 27, 2018
A new study of the role of healthcare provider recommendations on weight gain during pregnancy showed that while provider advice did influence gestational weight gain, only about one in four women received appropriate advice ...

Attitude during pregnancy affects weight gain

February 26, 2014
Overweight or obese women with the mentality that they are "eating for two" are more likely to experience excessive weight gain while pregnant, according to researchers at Penn State College of Medicine.

Weight gain between pregnancies linked to increased risk of gestational diabetes

August 1, 2017
The risk of developing gestational diabetes mellitus (GDM) increases with increased weight gain between pregnancies, according to a new study published in PLOS Medicine by Linn Sorbye of the University of Bergen, Norway, ...

Weight gain greater, less than recommended during pregnancy linked with increased risk of adverse outcomes

June 6, 2017
In an analysis that included more than 1.3 million pregnancies, weight gain during pregnancy that was greater or less than guideline recommendations was associated with a higher risk of adverse outcomes for mothers and infants, ...

Women want support managing their weight during pregnancy

November 2, 2017
Australian women want their healthcare providers to actively advise them about weight management during and after pregnancy, a Monash University study reveals.

Recommended for you

Blood test may identify gestational diabetes risk in first trimester

August 16, 2018
A blood test conducted as early as the 10th week of pregnancy may help identify women at risk for gestational diabetes, a pregnancy-related condition that poses potentially serious health risks for mothers and infants, according ...

Artificial placenta created in the laboratory

August 14, 2018
In order to better understand important biological membranes, it is necessary to explore new methods. Researchers at Vienna University of Technology (Vienna) have succeeded in creating an artificial placental barrier on a ...

The inequalities of prenatal stress

August 14, 2018
Exposure to an acute stress in utero can have long-term consequences extending into childhood – but only among children in poor households, according to a new Stanford study that looked at the long-term impact of acute, ...

Better studies needed on effectiveness of fertility awareness-based methods for contraception

August 10, 2018
A new systematic review provides the most comprehensive assessment to date on the scientific evidence estimating the effectiveness of various fertility awareness-based methods (FABMs) for contraception. "Effectiveness of ...

Inducing labor at 39 weeks reduces likelihood of C-sections

August 8, 2018
Inducing labor in healthy first-time mothers in the 39th week of pregnancy results in lower rates of cesarean sections compared with waiting for labor to begin naturally at full term, according to a multicenter study funded ...

Study finds behavioral changes insufficient at preventing early childhood obesity

August 7, 2018
Young children and their families in poor communities were able to make some achievable and sustainable behavioral changes during the longest and largest obesity prevention intervention, but, in the end, the results were ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.