May 11, 2006 -- Scientists have come up with a new clue about why weight loss may be particularly hard for obese black women.
The clue lies in the belly fat of the 14 extremely obese black women studied by Hisham Barakat, PhD, and colleagues. Barakat works in the medicine department of East Carolina University in Greenville, N.C.
Past studies have shown that "obese African-American women lose less weight and at a slower rate than Caucasian women do across a variety of treatments including conservative interventions, very low calorie intake, and surgery," Barakat's team writes in The Journal of Clinical Endocrinology & Metabolism.
Of course, those findings are generalizations, not an iron-clad rule.
Age and education level don't seem to totally account for that weight loss gap, the researchers note. So Barakat and colleagues looked at another possible influence.
Checking Belly Fat
The researchers studied 14 white women and 14 black women. All of the women were very obese, with a body mass index (BMI) of more than 40. A BMI of 30 or more is considered obese.
The women in Barakat's study had come to East Carolina University's surgery department for gastric bypass surgery. With the women's permission, doctors took fat samples from the women during surgery.
Some of that fat came from just below the women's skin. Other fat came from deep inside the abdominal region.
The scientists were especially interested in certain cellular receptors in the women's fat tissue. Those receptors act as docks for a chemical called adenosine and curb fat breakdown.
Belly Fat Clue
Barakat and colleagues found that the obese black women had more adenosine receptors in their deep abdominal fat than the obese white women.
The same wasn't true of fat tissue taken from just below the women's skin.
The researchers note that their findings don't totally explain why weight loss may be harder for obese black women than for obese white women. However, they write that the results "shed light on potential causes behind the lesser and slower rate of weight lose of obese [African-American] women."
"These findings might be helpful in designing new strategies for the control and prevention of obesity in [African-American women] and other women as well," write Barakat and colleagues.