Intermittent fasting enhances cancer therapy via autophagy-dependent and independent mechanisms: Evidence and implications

Table 1 Different types of intermittent fasting regimen

Subtype of intermittent fasting regimen	Description	Ref.
Alternate day fasting	Complete fasting or very low calories intake for 24 hours, every other day, every 3-4 days or 2 non-consecutive days per week; alternating with ad libitum feeding without restriction on the next day	[4]
Modified alternate day fasting	Fasting days with severe and specific calorie restriction, approximately 75% calorie-restricted on alternate days, with a single feeding on fasting days that allocates 25% of calorie requirements	[5]
5:2 diet	Two fasting days, either consecutive or non-consecutive (75% energy restriction), and five non-fasting days (No energy restriction) per week	[5,6]
Time-restricted feeding	An individual is allowed to eat within a feeding period of 4-12 hours and will fast for the rest of the day. Commonly practiced methods are: (1) 16/8 with a feeding period of 8 hours/day and 16 hours of fasting; and (2) 12/12 with equal feeding and fasting periods	[7]
Prolonged water-only fasting	Fasting for an extended period, usually carried out for 3 days to 21 days. During consecutive fasting days, only water is permitted without any food intake	[8,9]
Fasting-mimicking diet	Plant-based caloric-restricted diet (30%-50% of the normal caloric intake) for 4-7 consecutive days, followed by a refeeding ad libitum period once per month	[9]
Ramadan intermittent fasting	Obligatory fasting for Muslims in the month of Ramadan (29-30 days), which consists of no food or drink from dawn to sunset (approximately 12 hours)	[10]