This mouse study seems very promising, but there is a word missing here:

In consideration of the challenges and side effects associated with prolonged fasting in humans, we developed a low-calorie, low-protein and low-carbohydrate but high-fat 4-day fasting mimicking diet (FMD) that causes changes in the levels of specific growth factors, glucose, and ketone bodies similar to those caused by water-only fasting (Brandhorst et al., 2015) (see also Figure S1 for metabolic cage studies). Here, we examine whether cycles of the FMD are able to promote the generation of insulin-producing β cells and investigate the mechanisms responsible for these effects.

It’s called “ketogenic,” people. Kee Toe Jen Ick. Low carb, high fat.