Older women on a so-called Paleolithic diet – which tries to mimic the diet of cavemen living in the stone age - may be more likely to develop iodine deficiency than their counterparts who don’t eat this way, a small Swedish experiment suggests.

The Paleo diet is rich in lean meats, fish and seafood, fruits, vegetables, eggs and nuts. It excludes things like dairy, grains, sugar and salt.

For the experiment, researchers enrolled 70 overweight or obese older women. They randomly assigned 35 of the women to follow a Paleo diet, with 30 percent of their calories coming from protein, 40 percent from fats and 30 percent from carbohydrates.

The other 35 women were instructed to follow a diet based on Nordic recommendations, which aimed for 15 percent of calories from protein, 25 to 30 percent from fats and 55 to 60 percent from carbohydrates.

After two years, the women in the Paleo group had lost more weight – but they were also more likely to develop mild iodine deficiency, the study found.