Sperm quality is better among men who eat more fresh fish, fruits and vegetables and less junk food or red meat, researchers said. Three studies bring out the importance of lifestyle of a prospective father as well as that of his female partner in determining whether or not they can have a baby. Sperm quality was found to be better among those who took brisk walks, compared with those who either did little physical activity or went running. In the first study, researchers at the Harvard School of Public Health looked at what 188 students ate and drank, the Telegraph reports. They divided their diets into a 'prudent' one characterised by high intake of fish, fruits, vegetables and pulses, and a "western" one, full of pizza, red and processed meat, high energy drinks and snacks. Those with the best diet had 11 percent more motile sperms - better at swimming towards an egg - than those with the least healthy eating habits. "Motility is most important for couples who want to try to conceive naturally. A small increase could lead to a small increase in fertility," said Audrey Gaskins who led the study. A separate study at Harvard analysed the diet of 99 men who were already attending a fertility clinic because their wives or girlfriends were unable to conceive. Academics found that consumption of Trans Fatty Acids - previously found in many fried fast food joints but now being phased out - was linked to sperm concentration. A third paper by Yamaguchi University School of Medicine in Japan compared sperm motility among 215 men after analysing their physical activity in an average week. It found that those who exercised moderately, such as brisk walking, had better swimming sperm than those who did little physical activity or did strenuous work.