At this moment, it is believed that no one can deny that the trend of eating in the form of IF or Intermittent Fasting, or periodic fasting, is very popular. We must have heard the mysterious group of numbers “IF 18/6, IF 20/4, or IF 23/1” from beauty enthusiasts and health-conscious women around us.
The belief that periodic fasting like IF has health and beauty benefits simultaneously, such as helping to lose weight and reduce body fat without having to control the amount of food. Importantly, you can eat any amount and energy without limitation. It may also help slow down aging, which makes it very popular, being shared word-of-mouth and becoming a trending health and beauty search term over the past 2–3 years.
For dieticians, Intermittent Fasting (IF) is the practice of periodic fasting, specifying clear eating and fasting periods without focusing on calorie intake. There are four methods:
1.) Alternate-day Fasting allows for normal eating without energy restrictions on certain days, alternating with total fasting days, where only water and non-caloric drinks are consumed. It’s usually divided into Fast Days, fasting 2 non-consecutive days per week, and Feast Days, eating without restrictions 5 days per week.
2.) Modified Alternate-day Fasting allows for low-energy food (about 500 kilocalories per day) or low-calorie drinks such as black coffee, black tea, or herbal drinks without milk and sugar on fasting days, making it easier than Alternate-day Fasting.
3.) Time-restricted Feeding, which is the most popular form and commonly referred to as IF, such as IF 18/6, IF 20/4, or IF 23/1.
For example, IF 18/6 means fasting for 18 hours per day and eating during a 6-hour window, within which you can eat any amount of food and calories without limits.
4.) Religious Fasting
– Buddhism: One consumes only two main meals, breakfast and lunch (before noon).
– Christianity: Certain sects, such as the Seventh Day Adventists and the Latter-day Saints, practice fasting.
– Islam: Fasts during the month of Ramadan, consuming food only after sunset until before sunrise.
Patients with diabetes seeking to control weight and blood sugar can also use IF or periodic fasting. They should consult a medical team, diabetes educators, or dieticians before starting fasting to receive appropriate guidance, including adjusting oral medication and insulin to prevent symptoms.
This can be divided into three groups, depending on the type of medication used:
1.) Medications that do not cause low blood sugar, such as Metformin Hydrochloride or Pioglitazone.
2.) Medications that may cause low blood sugar or include insulin injections, such as Sulfonylureas.
3.) Insulin injections only.
Users in group 1 do not need to adjust their medication and can begin periodic fasting immediately, while groups 2 and 3 should consult their doctors to adjust medication to fit their altered eating patterns.
For diabetic patients, side effects of IF may occur, such as fatigue, lack of energy, headaches, dehydration, and low blood sugar during fasting periods. Overeating during non-fasting periods may cause post-meal hyperglycemia. Therefore, it is advised for diabetics practicing periodic fasting to pay attention to properly adjusting their diet during regular meals for improved health.
Best regards,
Natiarika Puneo
Professional Dietitian
Bangkok Chiang Mai Hospital
Thanks to the information from
Thai Dietetic Association Journal, Year 39, Issue 1–3, Jan–Dec 2019
Intermittent Fasting and Weight Loss in Diabetics by Assistant Professor Dr. Wantanee Kriengsinyot, Diabetes Association of Thailand
Intermittent Fasting for Thai Diabetes Friends by Smithit Chotisrilakha, Dietitian, Phramongkutklao Hospital, Committee, Thai Dietetic Association
