A five-year study undertaken by Dr. Romain Barres of the University of Copenhagen has revealed that the sperm of thin and obese men have different genetic markers, which could change gene behavior in the body. Dr Romain Barres believes it is wrong for health advice (not to drink alcohol, to stay away from pollutants, to eat a balanced diet, etc.) to be exclusively targeted at women during pregnancy. To come to this conclusion, the researchers tested the sperm of six obese men who were undergoing bariatric surgery to reduce the volume of their stomach.