'Halo effect' noted among family members of bariatric surgery patients

Obese family members and children of patients who underwent Roux-en-Y gastric bypass surgery had lower BMIs and improved physical activity and eating habits after the procedure, according to results of a study published online.

"Weight changes and lifestyle modification may be social contagions," researchers at the University of Stanford School of Medicine in California wrote. "If one member of the family makes drastic lifestyle changes following surgery, it is possible that other family members will adopt similar healthy habits."

To investigate this concept, the researchers examined the families of 35 patients who underwent Roux-en-Y gastric bypass surgery at their center between 2007 and 2009. Besides the patients, 35 adult family members and 15 children aged younger than 18 years participated in the study. Inclusion criteria dictated that families also attend three sessions after the procedure with the patient that included dietary recommendations and encouragement to increase physical activity.

Before surgery, approximately 60% of adult family members and 73% of children were obese, the researchers reported. At 1 year, mean weight among all adult family members was nonsignificant, decreasing from 220 lb to 198 lb. Obese adults, however, experienced a significant reduction from 234 lb to 226 lb (P=.01) in mean weight. Similarly, the decrease in waist circumference from 119 cm to 111 cm (P=.03) observed among obese adults reached statistical significance compared with that exhibited by nonobese adults (108 cm to 105 cm).

The researchers accounted for natural growth in children by using BMI for sex and age growth curves from the CDC to predict 1-year postoperative BMI if the child continued on his or her current growth trajectory. Results revealed that only obese children had a lower mean BMI than expected (29.6 vs. 31.2; P=.07).

The researchers also noted improvements in eating habits among adult family members, demonstrating decreases in uncontrollable eating (P=.01), emotional eating (P=.04) and alcohol consumption (P=.009). They also observed increases in daily physical activity from 7.8 to 16.8 metabolic equivalent task-hours among adults and from 12.9 to 22.4 metabolic equivalent task-hours among children.

"Obesity is a family health concern," the researchers wrote. "This study demonstrates that performing a gastric bypass operation on one patient has a halo of positive effect on the weight, eating habits, activity level and health behaviors of the entire family."

For more information:

Woodard GA. Arch Surg. 2011;146:1185-1190.

Disclosure: The researchers report no relevant financial disclosures.

Follow EndocrineToday.com on Twitter.