The present book deals with the biochemical changes of obese peoples after undergoing one of the ordinary bariatric procedures; (Laparoscopic sleeve gastrostomy (LSG), Roux-en-Y gastric bypass (RYGB) & intragastric balloon (IGB). Glycated hemoglobin A1c (HbA1c), fasting blood glucose and lipid profile levels in addition ghrelin and leptin concentrations were determined in the sera of patients before and after surgeries. This book discussed the results obtained from patients and the effect of different surgeries on the changes in the measured paratemtes in the obese patients.