Halo Effect for Bariatric Surgery: Collateral Weight Loss in Patients' Family Members

Context: Bariatric surgery is an effective treatment for morbid obesity, which is increasingly recognized as a familial disease. Healthy behavior transmission may be enhanced by family relationships.

Objective: To determine changes in weight and healthy behavior in patients who underwent Roux-en-Y gastric bypass surgery and their family members.

Design: Prospective, longitudinal, and multidimensional health assessment before and 1 year after index Roux-en-Y gastric bypass surgery.

Setting: An academic bariatric center of excellence, from January 1, 2007, through December 31, 2009.

Participants: Eighty-five participants (35 patients, 35 adult family members, and 15 children <18 years old).

Intervention: Roux-en-Y gastric bypass surgery and associated dietary and lifestyle counseling.

Main Outcome Measures: Weight and expected body mass index (calculated as weight in kilograms divided by height in meters squared). Secondary outcomes were waist circumference, quality of life (36-Item Short Form or Pediatric Quality of Life Inventory), healthy behaviors, eating behaviors, and activity levels.

Results: Participants were grouped by relationship to patient for analysis with paired 2-sample t tests. Before the operation, 60% of adult family members and 73% of children of patients undergoing Roux-en-Y gastric bypass surgery were obese. At 12 months after the operation, significant weight loss was observed in obese adult family members (from 234 to 226 lb; P = .01). There was a trend for obese children to have a lower body mass index than expected for their growth curve (31.2 expected vs 29.6 observed; P = .07). Family members increased their daily activity levels (adults, from 8 to 17 metabolic equivalent task-hours, P = .005; and children, from 13 to 22, P = .04). Adult family members also had improved eating habits with less uncontrollable eating (from 35 to 28; P = .01), emotional eating (from 36 to 28; P = .04), and alcohol consumption (from 11 drinks per month to 1 drink per month; P = .009).

Conclusion: Gastric bypass surgery may render an additional benefit of weight loss and improved healthy behavior for bariatric patients' family members.