> For all we know, our ancestors were eating berries and much less meat than we do That's not very likely and there are plenty of studies that back me up here

> For all we know, our ancestors were eating berries and much less meat than we do That's not very likely and there are plenty of studies that back me up here [1]. For a simple explanation as to why that's not likely look at the calorie counts for berries [2]. You'd have to eat about 10 pounds (~4.5 kg) of blackberries a day to get 2000 calories. There are other more calorie dense non-animal foods like nuts, but most likely around 65% of a hunter gatherer's calories came from meat [1]. This is much more than the amount of protein consumed by the average American today, who gets less than 20% of his or her calories from meat [3]. >yet we seem to live longer those days Most of the improvement in average lifespan is a result of the drastic decline in infant mortality rate. Hunter gatherers regularly lived into their 70s [4] and when you account for the decline in infant mortality the difference isn't as great as most people imagine. The combination of reduced infant mortality, medical care, and relative safety of civilization are what accounts for our increased lifespan. It's very likely (almost certain given the obesity numbers) that our modern diet is driving the numbers down below what they should be given our other advances. > That's why we run clinical studies. To find out answers. Yes it is, and those studies are showing that too much sugar (and most of western civilization eats too much sugar) leads to metabolic syndrome which leads to heart attacks. The debate is on whether sugar does this because it directly causes insulin resistance, or if it is just very calorie dense and thus eating too much simply causes weight gain, or if it reduces satiety and actually causes you to eat more. I'm not saying eating like a hunter gatherer is necessary for your health, and sure we need to do research--I'm not sure why you think I implied that we didn't. However, it seems logical (again the research we have done backs me up here) that our bodies may not be adapted to handle something we've never eaten in anywhere near the quantities we eat now--specifically the fructose in sugar. [1] http://www.ncbi.nlm.nih.gov/pubmed/11965522 http://www.ncbi.nlm.nih.gov/pubmed/11965522 [2] http://calorielab.com/foods/berries/66 http://calorielab.com/foods/berries/66 [3] http://ajcn.nutrition.org/content/87/5/1554S.full http://ajcn.nutrition.org/content/87/5/1554S.full [4] http://www.anth.ucsb.edu/faculty/gurven/papers/GurvenKaplan2007pdr.pdf http://www.anth.ucsb.edu/faculty/gurven/papers/GurvenKaplan2...