After gastric bypass surgery, levels of free fatty acids in the blood rose and stayed higher than after dieting alone, even when people consumed the same number of calories, suggesting that the...

After one month, morbidly obese women who had gastric bypass surgery lost a higher percentage of body fat than those who followed a low-calorie diet, even though both groups lost the same amount of total weight. This suggests that the surgery affects fat metabolism in a way that diet alone does not.

After gastric bypass surgery, liver fat levels did not decrease significantly even though patients lost a lot of body fat, but when people lost the same amount of weight by eating fewer calories, their liver fat dropped substantially. This suggests that the method of weight loss affects liver fat differently.