I have to admit that I've never engaged in a voluntary fast. It kinda shows. ;c)

That being said I would suggest that you be aware of the medical side of what goes on when the body goes on a fast. Things like eventually reducing the acid level within your stomach, and how the body prioritizes fat but will proceed to consume muscle should there be a shortage in fat.

Also, keep in mind that a 'little' fat is actually a good thing. It is the energy reserve that the body feeds upon when there is a shortfall - especially useful for resisting and riding out periods of illness.

For both these reasons I would suggest that a long-term adjustment (and lifestyles require a degree of stability even if intermittent fasting has its weight-loss uses), is to incorporate eggs, dried fruits and nuts into your weekly, if not daily diet.

Eggs are a source for cholesterol - which semi-surprisingly is used by the body to repair the body's cells.

Nuts and dried fruits are sources for a wide range of minerals that can be stockpiled (and are not expensive if kept to small portions (little plastic containers help)).

Keep wheat grains to a minimum as the body loves to metabolize that into sugars and fat (and can play a big role in bringing about or worsening diabetes cases).

If you keep your macchiatas and hot chocs to the morning and early afternoon then you'll sleep better at night. ^_^

Well all this merely constitutes an alternative view. All the best with your program. :c)