Bariatric Surgery / Obesity / Humans / Fasting / Female / Body Composition / Male / Nutritional Status / Aged / Intestines / Middle Aged / Adult / Odds ratio / Citrulline / Electric Impedance / Glutamic Acid / Case Control Studies / Body Composition / Male / Nutritional Status / Aged / Intestines / Middle Aged / Adult / Odds ratio / Citrulline / Electric Impedance / Glutamic Acid / Case Control Studies