Home > Diet and nutrition > Nutrition basics Updated 12 July 2013 Paleo diet: not a diet of logic Eating meat as we do equals ecological disaster in the long run, experts have warned. 7 iStock Related South Africa's 'hidden hunger' Save water: eat less meat Free-range, organic, grass-fed: do you know what you're eating? Don't eat the planet Check Glycaemic index tool » Count Calorie counter » Quiz Ready for weight loss? » Ask DietDoc » The lowdown on low-carbs 8 microwave myths Our current culinary obsession and huge appetite for food is having a detrimental impact on the planet, with a serious global focus on food security and sustainability. In 2006, The UN issued a warning linking animal farming to high greenhouse gas emissions and other environmental damage implying that eating meat as we do equals disaster in the long run.According to the Mail & Guardian newspaper, a report by the United Nations' Food & Agriculture Organisation says by 2050, with a projected world population of nine billion people, we won't be able to feed everyone at current levels of food production. The reporter goes on to put a case forward for eating insects as part of our staple diet - a practice called entomophagy, which is already quite common around the world.The global warming phenomenon has sparked a wave of ethical eating spinoffs and we've seen the rise of farmers' markets, 'organic' and 'free range' produce popular eating plans like the Paleo diet. Heart disease, cancer and diabetesThe diet, which is believed to improve health and minimise the risk of chronic disease and encourage weight loss, is based on modern foods that mimic those consumed by pre-agricultural, hunter-gatherer Paleolithic ancestors. (The era in question was from about 2.5 million years ago until about 10 000 years ago when humans started cultivating crops and raising animals for food, and it is here that we have seen the rise of heart disease, obesity, cancer, diabetes and other inflammatory ailments.) The diet advocates a higher intake of protein, fibre, omega-3 fats and more vitamins, minerals and antioxidants and less carbohydrates, processed, salty foods and acidic foods. But were our ancestors fit and healthy? According to critics of the Paleo diet our ancestors did not live beyond 40 - in fact death before 15 was far more common - and they may not have had the best immune systems or sanitation, leaving them open to parasites, high cholesterol and other bacterial/viral infections. 'Privilege rather than logic'According to one Scientific American writer, it is ludicrous to promote a single Paleo diet as there were four different types of hunter gatherers across the globe and no definitive optimal diet.It refers to the Paleo diet as one "founded on privilege rather than logic".Going back to the meaty debate, according to a Worldwatch Institute survey, people in South Africa eat in excess of 17kg of beef, 24kg of poultry and 4kg of mutton per year.Although human beings have long been omnivorous, there has always been a split in our tendencies. According to Brendan Billings, Maropeng's Bone Detective and University of the Witwatersrand scientist, about 2.5 million years ago there were two groups of hominids. They would not have looked entirely human but both walked upright. One group preferred vegetables, but they did eat a bit of meat. Everything they ate was raw, and they had very different jaws to us - big, powerful jaws that can crush seeds, hard nuts and other vegetation. "Basically this animal had a tough consistency in the diet," says Billings. Our direct ancestorsThe other group ate a balance of meat and vegetable matter, and it is believed that they were able to make fire or as Billings says perhaps they were foraging and would opportunistically find a carcass that had been caught in a veld fire or fire caused by lightning. So they would eat cooked food. They had much smaller jaws and teeth, similar to ours. "This animal had a less consistent dependence on harder foods," Billings explains, adding that recent data of micro wear on tooth structure indicates that both groups had a similar diet but the one (Robustus) is more consistent with a harder, tougher diet than the other (gracile australopithicines). No guesses as to which group would evolve into human beings. Our direct ancestors, archaic modern humans are thought to have derived from Homo ergaster, share the same genus as our own species, Homo sapiens. Fossil records indicate that their evolutionary line came to an end just over a million years ago.The first ever SA 'braai'Scientists say that eating meat was essential as the intake of protein and the synthesis of the muscles and brain, resulting in the brain developing over the next 2 million years. Protein ingestion never resulted in the brain developing but provided the means to accommodate a developing brain.Interesting enough, Billings says insects provided a good supply of protein to accommodate the needs required to sustain a developing brain.The earliest fossil evidence of controlled fire in southern Africa - the first ever South African "braai" - was discovered at Swartkrans and dates back to about 1 million years ago. The latest thinking is that perhaps there may be an evolutionary need to change the way we eat. While diet may have played a big part in our evolution, the big question now is whether we choose to evolve in order to save our environment. Just a suggestion by the scientific icon Albert Einstein who said: "Nothing will benefit human health and increase chances of survival of life on Earth as much as the evolution to a vegetarian diet."For more interesting food facts, visit www.maropeng.co.za or visit worldwatch.org. To book for the next Bone Detectives Tour on 27 July, followed by dinner with Brendon Billings (special B&B hotel rates apply) contact 014 577 9000. Please note this tour is for adults only and commences with welcome drinks at 18:00 at the Maropeng Boutique Hotel.- (Maropeng press release) More in Diet and nutrition Try the Meat Free Movember Challenge More: Diet and nutritionNutrition basics advertisement Get a quote Momentum - save up to 35% on healthcare advertisement Read Health24’s Comments Policy Comment on this story 7 comments Comments have been closed for this article. Logout Comment 0 characters remaining Share on Facebook Loading comments... From our sponsors How will we feed 9 billion people? Try the Meat Free Movember Challenge Fit starts now with MRP Sport Get Race Ready with REHIDRAT® Live healthier Toilet matters » 45 toilets in the world Poop in weird places Toilet paper debate The funniest bathroom signs ever These signs have taken toilet humour to the next level. Too Tired? » 20 signs of burnout Staying active reduces stress 10 ways to have a healthier work day Why you're exhausted Lost your mojo? Here are 5 surprising energy drainers, plus the easy fixes that will help put the pep back in your step!