Paleo fail: meat-heavy low-carbohydrate diets can shorten lifespan, researchers say

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 less than 40 per cent of total energy intake from carbohydrates qualified as a low-carb regimen, though many such diets reduce the share to 20 per cent or less.

At the other extreme, a 70 per cent or higher share of carbohydrates – such as pasta, rice, cakes, sugary drinks – can also reduce longevity, but by far less, the scientists found.

“Low-carb diets that replace carbohydrates with protein or fat are gaining widespread popularity as a health and weight loss strategy,” said lead author Sara Seidelmann, a researcher at Brigham and Women’s Hospital in Boston.