@kaaskoek there's various forms of fasting. I started with my fast days being 600 calories for a few months and then recently I changed to no-food-fasting and I consume about 3 to 4 cups of nescafe classic coffee with 15ml clover full cream milk per cup. Coffee suppresses appetite but don't add sugar to it as that will add calories. I can now manage fast days with just coffee, water and green tea. I keep my calories to +/-40 calories.