Irish nutrition experts have warned people against high-protein, Atkins-style diets after an international study found they could reduce the chances of women getting pregnant. Liam Reid reports.
The study by US fertility experts is the latest to cast doubt about such diets, which have become increasingly popular among people trying to shed weight.
The diet has been linked to high fat consumption and cholesterol levels, while others reported negative effects include constipation, halitosis, fatigue and headaches.
The new study suggests that women who eat too much protein could reduce the chances of a fertilised embryo attaching to the wall of a womb.
A very high-protein diet has also been linked by the research to hindering early foetal development. Although the research was done on mice, scientists believe there are implications for humans.
"It's conceivable that people who have protein intakes greater than 30 per cent may have problems conceiving," said Dr David Gardner, of the Colorado Centre for Reproductive Medicine, who led the US study.
The research stems from the observation that protein in the diet affects levels of ammonium in the female reproductive tract. It found that female mice on high-protein diets experienced higher ammonium levels. Embryos from the high-protein mice had a greater failure rate in attaching to womb walls of surrogate mice compared with embryos from low-protein diet mice.
Last night, Ms Sarah Keogh, a dietician and spokeswoman for the Irish Nutrition and Dietetic Institute, said the study "adds to concerns dieticians and other health professionals have about very high-protein diets.
"People trying to lose weight need to look carefully at the diet they choose, and should try to get good information about their food choices.
"Too much of any food nutrient can be almost as bad as too little," she added.