What is the Paleo diet, how does it work, is it safe and which celebrities have tried it?
AS obesity rates continue to rise, Britain's obsession with junk food and increasingly lethargic lifestyles has become a cause for concern.
But in recent years, the Paleo diet trend has seen more and more people ditch modern eating habits altogether and reverting to a caveman diet.
What is the Paleo Diet and how does it work?
People on the Paleo Diet only eat foods which could have been hunted, fished or gathered in caveman days.
The diet goes back before the invention of farming, meaning that grains such as wheat, dairy, alcohol, coffee, refined sugar, potatoes and salt are all off the menu.
All processed foods are also banned, while Paleo meals tends to be low-carbohydrate and high-protein.
A typical Paleo meal would be made up of meat or fish, served with accompaniments such as eggs, nuts, seeds, fruit, vegetables, herbs and spices.
The statement added: "A diet with fewer processed foods, less sugar and salt is actually a good idea, but unless for medical reason, there is absolutely no need to cut any food group out of your diet.
"In fact, by cutting out dairy completely from the diet, without very careful substitution, you could be in danger of compromising your bone health because of a lack of calcium.
"An unbalanced, time consuming, socially isolating diet, which this could easily be, is a sure-fire way to develop nutrient deficiencies, which can compromise health and your relationship with food."
Which celebrities follow a Paleo Diet?
Sharon and Ozzy's son Jack Osbourne turned to Paleo after being diagnosed with multiple sclerosis, for which there is currently no known cure.
MS is an autoimmune disease that attacks the central nervous system, and Jack was drawn to the anti-inflammatory benefits of the Paleo Diet.
He told ABC News: "At its core, I look at MS as inflammation, so I try and eliminate foods that cause inflammation: dairy, gluten and grains."
Hollywood actress Jessica Biel, who recently wowed at the Golden Globes, is also a fan.
She told CrossFit Zone: "It just leans you down and slims you up and takes that little layer of fat, skin, and water-weight right off your body."
While sex symbol Megan Fox shed her baby weight by sticking to a Paleo Diet.
She told US Weekly: "Try and stay away from dairy - especially if you're a woman! It's really hard on your hormones."
And The Voice judge Tom Jones lost 2st 7lb in just five months after going Paleo.
Matthew McConaughey and Uma Thurman are also said to be fans.
Are there any success stories on the Paleo Diet?
It's not just wealthy celebs who have turned to Paleo - scores of ordinary people have bid goodbye to obesity thanks to the plan.
Aussie Elora Harre dropped six dress sizes and shed more than eight stone on the caveman diet.
The 23-year-old went from a size 24 to healthy size 12, after turning her back on pizza, burgers and kebabs - which she had previously eaten for breakfast.
While LA-based George Prior also follows a strict Paleo diet, which keeps him looking trim.
Is yo-yo dieting healthy?
Fad diets have continued to divide nutrition experts - some believe there are clear benefits, while others worry that the temporary fixes can have lasting impacts on your health.
Dr David Allison said serial slimmers live longer than those who simply remain fat.
Speaking at the world’s largest science gathering, he revealed only 10 per cent succeed in losing a clinically meaningful amount of weight and keep it off.
But he said tubby Brits should not give up hope – and simply try another slimming regime.
Despite this, another Brit scientist criticised yo-yo dieting – saying fans end up flabbier in the long run.