I don’t think the Keto diet is healthy. It doesn’t provide enough fiber for healthy gut bacteria. It doesn’t provide a wealth of vitamins, minerals and phytonutrients that you get from eating lots of complex-carb vegetables and fruits. Also, people who practice it make light of the hazards associated with saturated fat and heart disease, which I consider a serious issue. Having said all that, I do think there can be a subtle role for using Keto in order to extend the ketosis one experiences with intermittent fasting.
Let me explain. I do a 19:5 regimen with intermittent fasting. To my mind, this means that ketosis starts to build around the 12th hour from my last meal. So, with 19:5, I should be getting an escalating ketosis that lasts about 7 hours — from the 12th to the 19th hour of my fasting period.
Question is, is there a viable way to maximize ketosis past the next meal for another 19 hours? This is where Keto may come in handy. If at the next meal, one eats an extremely low — as in insignificant — amount of carbohydrates, but an excessive amount of fat, then the body doesn’t spike insulin, and is left with only fat as an energy source.
Doing this strategy — an extremely high-fat but extremely low-carb OMAD meal — it is very possible to radically reduce your calorie count for that day, as all that fat induces satiety on far fewer calories than what you eat normally. This means that over the following 19-hour fasting period, burning body fat will happen much sooner (perhaps starting at the 6th hour instead of the 12th) because the body will burn through the fewer-than-normal calories from the food sooner, and so instead of 7 hours of ketosis, I might be experiencing up to 13 hours of escalating ketosis in this subsequent fasting period — a win win.
So I think a judicious and selective use of Keto with intermittent fasting could have significant benefits relative to burning body fat, even though I think Keto as your basic diet is unhealthy, even dangerous.