Abstract
BACKGROUND: Early identification of the potential to adopt a long-term unhealthy diet, could improve weight outcomes for patients having undergone bariatric surgery. OBJECTIVES: We explored whether presurgical sociodemographic and lifestyle characteristics, together with the type of surgery, could predict 10-year changes in dietary intake after bariatric surgery. SETTING: Surgical departments and primary healthcare centers, nationwide. METHODS: Participants were from the Swedish Obese Subjects study, a matched (nonrandomized) prospective trial comparing bariatric surgery with standard care for obese patients. This study included the 1695 surgery patients with complete information on presurgery diet. Questionnaires were completed before and 6 months, 1-4, 6, 8, and 10 years after surgery. Analyses were conducted with linear mixed-model. RESULTS: Dietary changes were observed in 1561, 1298, and 1243 participants, at the 2-, 6-, and 10-year follow-ups, respectively. Sex and treatment type predicted changes in energy, carbohydrate, protein, and fiber intake over the follow-up (P<.05). Furthermore, male sex, younger age, a sedentary behavior, and gastric bypass predicted increased alcohol consumption (P<.001). Two important phases for intervening bariatric patients' diet were identified. The first was 6 months after surgery, when the maximal changes in diet were achieved. The second, stretched from 6 months until 4 years after surgery, during which earlier commitments to dietary changes were largely abandoned. CONCLUSIONS: Male sex and banding surgery in particular predicted unfavorable post-surgery changes in energy and macronutrient intake. Furthermore, gastric bypass, a younger age, and an unhealthy lifestyle presurgery, may predispose individuals to increased alcohol intake after surgery.