The paleo diet has been sweeping across the globe for some time, but is now being questioned by experts.
The diet is supposed to be based upon what prehistoric humans during the Paleolithic (Stone) Age would have eaten about 2 million to 10,000 years ago.
Dieters avoid dairy, agricultural products, and processed food, but do eat grass-fed meats, nuts, seeds, oils, eggs, vegetables (except those high in starch) and fruits.
Dr. Jane Scott, a researcher at Curtin University in Australia, told WA Today:
The reason why some people think it's the best thing since sliced bread, even though they don't eat the sliced bread, is the fact that a lot of people actually do lose weight when they first go on it.
That's because when you cut out your carbohydrates, the cereals and things, you actually cut out a lot of junk food and things which have lots of sugar. Out go the cakes, biscuits, pastries and snack foods.
Professor Marlene Zuk, an evolutionary biologist at the University of Minnesota, questions the prehistoric claims of the paleo diet.
Zuk told the Daily Mail:
The Paleo diet is based on the idea that human genetics have not changed or evolved over the past 10,000 years, since the time before the use of agriculture.
But plenty of evidence exists that our genes have changed over the last few thousand years, and these changes mean we can eat foods our hunter-gatherer ancestors could not.
Little is known about what our ancestors actually ate and they may have had many different diets depending on where they lived.
Almost all of the foods available today are vastly different from the forms that our Paleolithic ancestors would have eaten, and this does not just mean ice cream, chips or even flour, but basics such as meats, fruit and vegetables.
Trying to emulate what people ate 10,000 or 100,000 years ago is impossible.
Dietitians Association of Australia president Liz Kellett told WA Today that people on the paleo diet could be "in danger of missing out on some key nutrients."
Calcium in particular is an issue, particularly if you get adolescents going on the diet because our teenage and early adult years is when we attain our peak bone mass which protects us from osteoporosis.
Young girls in particular who go on this could find themselves at risk down the track. One of the saving graces of these diets is that people only give them a try and don't last too long on them.