A. For many people, intermittent fasting is safe, but it is not the same for everyone. People suffering from kidney stones, gastric reflux, severe diabetes, or other medical issues require extra attention. Also, breastfeeding and pregnant women must avoid it as it can hamper the infant's or foetus's growth. However, fasting for two days can be helpful for healthy people with no pre-existing chronic disease. In addition, it protects against diabetes, heart disease, and certain types of cancer.