Our ancestors could not rely on the kosher butcher for their meat
Those watching their weight and contemplating the impact of the party season should consider one sobering fact - cavemen did not eat starchy deep fried snacks. Humans were never designed to digest the foods which have propelled the western world into an obesity crisis.
Oil? Our hunter-gatherer ancestors did not have the technology to make it, and they did not hang around long enough to grow the crops that produce oil, or indeed those which make bread or pasta.
Nor did they eat any dairy - so when you add butter and cheese to a list of banned foods that also includes potatoes, you can see that the Paleo Diet, based on ancient dietary customs, is a tough regime for Jews to follow.
That has not prevented the diet becoming a rip-roaring success since being popularised by evolutionary medicine specialist Dr Loren Cordain. Now he has followed up his 2002 best-seller with the Paleo Diet Cookbook. This is due to hit our shelves in time for the New Year diet season, and concerned fatties who really want to shed their spare tyre might want to consider the science which underpins its recipes.
I know of very few illnesses that don't respond to the diet
It comes down to a principle called Optimal Foraging Theory, which primed our nomadic ancestors to limit themselves to whatever they could hunt or gather on the spot before moving on to new pastures.
According to Cordain, we can most easily replicate this foraging pattern by sticking to the outer aisles of the supermarket where fruit and veg and fresh fish are stocked, and keeping away from the dairy and processed delicacies down the middle.
"The diet nature intended for us is simplicity itself," claims Cordain - and indeed it is easy enough to remember that lean meat, poultry and fish, plus all fresh fruit and vegetables apart from potatoes and sweetcorn are on the menu.
But forget worsht and viennas - cavemen did not process their meat, and Cordain claims an awful lot of charcuterie is "more like fat disguised as meat".
Even when it comes to fresh meat, he considers salt beef and every part of the chicken except the breast too fatty for his diet sheet, let alone shoulder of lamb or chops.
Pickled cucumber, olives, salted nuts, ketchup and virtually all canned fish are off the list of permitted foods, and do not even consider peanut butter - not that you would, without any toast to spread it over.
But acknowledging that "it is imposible to eat only the Stone Age foods that were available to our ancestors", Cordain has added a few modern foods to the mix - olive, walnut, flaxseed and avocado oil, tea, coffee and booze in moderation, plus a handful of nuts and dried fruits. Eggs are OK too.
Which is good because without them, breakfast on the Paleo Diet would be a sorry affair - cornflakes, porridge, and, of course, bread, butter, cheese and yoghurt are all on the list of things to toss out of the kitchen.
That said, there are some intriguing recipes in the new cookbook guaranteed not to leave you feeling hungry. Breakfasts of stuffed trout or baked salmon might seem a bit out there, but you can always have poached eggs or an omelette, ideally with added veg. When it comes to adding some starchy comfort to dinners, sweet potatoes and squash are legitimate additions to the diet and also help assuage cravings for sugar.
Interestingly, the regime is almost the opposite of the biblical diet which was heavily based on grains, legumes and dairy. Fish was rare, and although there was plenty of goat meat and beef, it was only eaten on special occasions, as livestock were too valuable to be slaughtered.
The fact that such a large swathe of today's population is said to be allergic to wheat and dairy produce does give credence to the evolutionary theory that we were not designed to properly digest these much more modern foods.
Cordain claims that "scientific evidence increasingly implicates grains, dairy products, legumes and processed foods in type 2 diabetes, heart disease, high blood pressure gout, cancer, autoimmune diseases and others… I know of very few chronic illnesses that don't respond positively to the Paleo Diet."
Some would disagree - meat is not allowed on the Gerson Diet, which is sold as a culinary cure for cancer and other diseases, though it does ban dairy, salt and all but flaxseed oil, and advocates vast quantities of organic fruit and vegetables.
But there is little doubt that once cakes, biscuits and especially bread, plus the butter, cheese, jam and other naughty stuff we like to spread on it are out of the picture, weight loss is almost bound to follow.
And Cordain says that following his diet only 85 per cent of the time gives you the lion's share of the benefits; a cream cheese bagel once a week - or even a daily latke one week a year - is not going to kill you.
The Paleo Diet Cookbook will be published by Wiley in January at £13.99.