The Paleo diet, also known as the caveman diet, is an eating plan that takes things back to basics. And we mean way back.
It's a nutritional plan based on the presumed diet of Paleolithic times, which ended some 10,000 years ago. Yeah.
But unless you're a historian (or a really smart nutritionist), knowing how to go Paleo can be very confusing.
In his book 'Your Personal Paleo Diet', Chris Kresser offers some digestible help.
Why do people follow the Paleo diet?
"Both the fossil record and studies of contemporary hunter-gatherer cultures suggest our paleolithic forebears enjoyed excellent health: they were lean, fit and apparently free from chronic disease. The benefits of mimicking their lifestyle are undeniable.
"Those who walk the Paleo road report near effortless weight loss, new-found vitality, and often miraculous resolution of the most dire health issues; however, even the most dedicated 'Paleo purists' hit a wall. Weight loss stalls. Symptoms persist. Energy flags. People tire of restrictive eating" he writes.
Chris says that if you're starting out on the road to Paleo puritanism you must first complete a 30-day reset diet where you completely dedicate yourself to the caveman way.
"The reset diet is designed to reduce inflammation, improve digestion, burn fat, identify food sensitivities, reduce allergic reactions, boost energy, regulate blood sugar and stabilise your mood.
"Later on in the programme, you'll have more leeway to go off the rails every now and then. After all, there's more to life than food! But the reset phase is not one of those times. This is where you gather your strength and buckle down." Chris writes.
Here's what you can and can't eat during the reset period:
Your Personal Paleo Diet: Feel and look great by eating the foods that are ideal for your body, Chris Kessler, published by Piatkus, £13.99