- We examined the long term results of vertical banded gastroplasty 3-10 years after operation. They were assessed by weight lost, incidence and severity of untoward effects and improvement in diet and in quality of life in 75 of 122 who had had the operation. Average weight lost was 28.5 +/- 14.9 kg (p < 0.001) in 5 years and 58.6 +/- 30.4% of excess weight, which brought patients to within 32 +/- 25.2% of ideal weight. According to these measures, in 63-76% the operation had been successful in causing weight loss. The 2 criteria for successful weight loss were loss of more than 50% of weight in excess of ideal body weight and residual body weight less than 50% greater than ideal body weight. There was a greater risk of failure in unmarried subjects older than 45 (odds ratio for not losing weight was 6; in those weighing more than 120 kg it was 9). We saw evidence of this mostly 4 years after operation (odds ratio 11). The degree of success in weight loss was correlated with texture of food (softness) preferred and length of operation. Of those interviewed, only 65% were satisfied with their results. The greatest improvement in quality of life measurements was in physical activity, perception of health, and frequency of feeling depressed. Side-effects were vomiting, reflux and fatigue. Only 34.7% were able to digest solid foods, so that subjects are at risk for nutritional deficiencies.