Jaminet promotes a moderate carb diet — composed of "safe starches" but argues that many ketogenic dieters have
glucose deficiencies and it exacerbates their health problems. Additionally, he argues that low carb diets tend to promote fungal infections over the long term (the eukaryotes have mitochondria and it's believed they can adapt to ketones after a few months). He
wholeheartedly agrees that
some people need to be on low carb diets (diabetics, cancer patients, etc.), and he even offers a ketogenic version of the PHD for those people, but he says that
most people do better with moderate carb intake, particularly over the long term. The low toxin carbs ("safe starches") stave off glucose deficiencies and promote a healthier immune system and microbiota.
He extrapolated the macronutrient ratio by looking at how the body breaks down macronutrients during fasting, the composition of all cells in all living animals, and the composition in breast milk (adjusting for the higher carb requirements of children). Using these clues, he proposed a macronutrient ratio that mimics these clues: Total calories from ~10% protein, ~30% carbs, ~60% fat. And then he put together a list of low toxin and nutrient-dense foods to meet those macronutrient ratios.
It would be easy to dismiss his hypothesis if it weren't for fact that the PHD seems to be
curing a wide range of health problems. In particular interest is the large number of low carbers who saw many of their health issues vanish after increasing their safe starch consumption. However, the key isn't to just eat carbs, but rather
low toxin carbs that preferably provide adequate fermentable fibers for your gut bugs.
And, interestingly, what we are starting to see from the
American Gut Project — particularly if you read
Jeff Leach's blog posts — is that low carb diets just
don't provide enough prebiotics/fermentable carbs for your microbiota.