But Dr. Sherman Silber of the Infertility Center of St. Louis said that higher estrogen levels in obese men play only a minor role in sperm levels.
"We cannot expect to correct male infertility with a low fat diet, but of course, Americans are obese, and any weight reduction and fat reduction program would be welcome for health in general," he said. Silber said that the shape and size of sperm -- known as sperm morphology -- are largely determined by genetics.
Another doctor, Jamie Grifo of the NYU Fertility Center, argued that sperm count also does not necessarily affect a woman's ability to become pregnant, so the study conclusions have little relevance to fertility.
Grifo said patients with abnormal sperm morphology can "usually always get pregnant using intrauterine insemination [IUI] if you take the time." IUI is the placement of sperm directly into the uterus to facilitate fertilization. "The outcome is not changed by sperm count."
Attaman added that if future studies can replicate these findings, they can have a substantial impact on overall health.
"Although these findings need to be reproduced, adapting these nutritional modifications may not only be beneficial for reproductive health but for global general health as well," she said.