Introduction: Although bariatric surgery promotes dietary changes, many questions regarding their effect on weight loss remain unanswered.
Objective: The aim of this study was to evaluate changes in dietary intake and predictive factors of obesity remission in the first 12 months after RYGB.
Methods: Fifty-one patients (mean 39.34 ± 9.38 years, 68.7% women) who underwent RYGB were included in this study. Dietary intake was evaluated through a 24-h dietary recall and subsequently classified by NOVA, macronutrients and calories. The predictive factors for obesity remission within 12 months after RYGB were evaluated by Cox regression.
Results: At baseline, 62.7% of the patients presented severe obesity; mean excess weight loss was greater than 80% after 1 year of surgery and about 70% of the patients were no longer diagnosed with obesity. An increase in percentage of calories from protein was observed at 3 and 12 months after surgery. The caloric contribution of ultra-processed foods was low at 3 months after surgery while that of unprocessed or minimally processed foods was high at 3 and 12 months after surgery. From the Cox regression analysis, preoperative BMI (HR, 0.78; 95% CI, 0.69-0.88) and age (HR, 0.94; 95% CI, 0.89-0.99) showed an inverse association with obesity remission. Also, Δ protein (at 3 months-baseline) showed a positive association with obesity remission (HR, 1.06; 95% CI, 1.01-1.12).
Conclusion: Lower preoperative BMI, lower age, and higher protein intake at 3 months after surgery may favor remission of obesity in up to 12 months compared with baseline.
Keywords: Cox regression; Food intake; Gastric bypass; Macronutrients; NOVA.