Roux-en-Y gastric bypass (RYGBP) is the most popular surgical treatment for morbid obesity in the U.S.A., producing significant and durable weight loss with improvement in co-morbidities. Although a greater number of patients are undergoing surgical treatment for obesity, little data are available regarding their food intake after surgery. This study was undertaken to evaluate the caloric amount, nutrient composition and meal patterns of patients 18 months to 4 years after RYGBP. Ethnic differences in food intake were also investigated. Questionnaires were mailed to 360 patients who had undergone RYGBP at least 18 months prior to the onset of the study. Data were available from 69 patients, 52% Caucasian, 25% African-American, 23% Hispanic. 30 months after surgery, the average daily calorie intake was 1733 ± 630 kcal (n=68, range 624-3486 kcal), with 44% of calories from carbohydrates, 22% from protein and 33% from fat. Sugar-sweetened beverages represented 7% of total caloric intake. Patients consumed 3 meals and 3 snacks per day on average. Food intake from dinner and an evening snack represented 40% of the daily caloric intake. Snacks accounted for 37% of the daily intake. Percent excess weight loss (%EWL) was 58 ± 17% and was not different among ethnic groups. However, Hispanics reported consuming fewer snacks and fewer calories. %EWL correlated with the total daily caloric intake (r= .446, P <0.001). Follow-up attendance was 54% at 1 year after surgery but fell to 10% at 3 years. Only 77% of patients were taking vitamin supplements. RYGBP resulted in significant weight loss. Caloric intake was quite variable. Long-term follow-up remained low, putting patients at risk for metabolic and vitamin deficiencies. The relationship between caloric intake and long-term weight changes remains to be studied.