Middle-aged people who get roughly half their daily calories from carbohydrates live several years longer on average than those with meat-heavy low-carb diets, researchers reported Friday. The findings, published in The Lancet medical journal, challenge a trend in Europe and North America toward so-called Paleo diets that shun carbohydrates in favour of animal protein and fat. Proponents of these "Stone Age" diets argue that the rapid shift 10,000 years ago -- with the advent of agriculture -- to grains, dairy and legumes has not allowed the human body enough time to adapt to these high-carb foods. For the study, receiving...