Intermittent fasting (IF) is currently one of the world’s most popular health and fitness trends. Many studies show that it can have powerful effects on your body and brain and may even help you live longer.
Studies suggest that consuming two meals a day with complete food restriction in between the meals is sufficient to lower blood glucose and lipid levels. This simple dietary approach activates a cell ‘‘cleansing system’’ called autophagy in liver, fat, brain, and muscle that helps prevent obesity and diabetes. Cells possess dedicated mechanisms for the removal of damaged molecules and organelles. This process keeps your body in balance by self-removing cells that are no longer functioning optimally or appropriately.
IF is an eating pattern that cycles between periods of fasting and eating. In this respect, it’s not a diet in the conventional sense but more accurately described as an eating pattern.
INTERMITTENT FASTING PROTOCOLS
Most of the protocols consist of a period of at least 16 or 18 hours of fast and a refeeding window – 8 and 6 hours respectively (that’s 16:8, 18:6). There are more protocols (12, 10, 20 hours of fast or even prolonged fasting for 24 hours – only one meal a day- , 36 hours or longer), they invariably bring far more benefits to one’s wellbeing compared to eating regularly every day.
Intermittent fasting can be done in different ways. To generate a fasting window of 16 hours, you can eat twice: breakfast at 8:30 am and then dinner at 16:30, or if it suits you better, breakfast at 12:30 and dinner at 20:30. It means you fast for 16 hours and re-feed in the remaining 8 hour window. Many people find the 16/8 method to be the simplest, most sustainable and easiest to stick to. It’s also the most popular. The other standard protocol is 18:6. You fast for 18 hours and then, you can have two meals in your re-feed 6 hour window, breakfast at 8:30 and dinner at 14:30, or if it’s more convenient, a meal at 14:30 and dinner at 20:30.
Less experienced fasters can do a 12:12, fasting/feeding cycle, with 3 meals, and then, 14:10 with only two meals. This would be just for beginners; you will be able to experience better results for loss weight and mental/physical condition with the standard protocols and if you do it for at least a month.
BEST FOODS FOR INTERMITTENT FASTING
The liver can store a maximum of about 600 to700 calories worth of glucose. During normal daily activities, these glucose stores are usually depleted within about ten to twelve hours of not eating, and more slowly during sleep. Every time someone eats, their liver’s glucose stores are replenished. This is why avoiding carbohydrates, particularly added sugars and refined grains is a good idea during your eating period.
A meal that’s high in refined sugars and grains is quickly broken down into sugar and won’t keep you feeling full for very long. Moreover, this will cause your blood sugar and insulin levels to rise more quickly than if you ate a meal that contained fiber and whole grains like fresh fruit with a bowl of oatmeal. You should avoid sugar in juice, soda, coffee drinks, baked goods, as well as many flavored yogurts and yogurt drink.
If you’re trying intermittent fasting to lose weight, it’s still important to eat well to keep insulin levels stable and prevent spikes. Insulin is a hormone made in the pancreas that decreases blood sugar by moving it into our cells where it can be used as fuel or stored as body fat. Research shows that a higher level of insulin prevents fat from being broken down for energy. And if you’re not toned or very active, a lot of that extra sugar is going to end up in your liver where it can cause a fatty liver and weight gain.
You can eat high-fiber foods to suppress hunger, such as nuts, beans, fruits and vegetables, and high protein foods, including meat, fish, tofu, or nuts, during your eating window. You should drink lots of water and black coffee or tea, or cinnamon or licorice herbal teas for their appetite-suppressing effects. Try not to eat between your two meals during your eating window, but if you can’t help it, you can eat nuts, edible wild berries or avocado. The Ketogenic diet – high in fat and low in carbs – brings the same beneficial metabolic changes as intermittent fasting. Both trigger autophagy by not overwhelming the body with an external load, so it gives the body a break to focus on its own health and repair.
If you plan to be in ketosis during this diet, you should include lot of vegetables and fruits (rich in vitamins, minerals, fibre and trace nutrients), marine foods (rich in iodine and essential fatty acids), coconut oil and coconut derived products, olive oil (for salad dressing, don’t heat it), eggs, organ meats and fatty meats. Always look for high quality meat or fish, besides concentrating nutrients, organ meats and fish also concentrate toxic chemicals.
Some youngsters use strength training and/or calisthenics (body weight exercises) and do daily intermittent fasting for 2, 6, 8 months or even longer and they experience significant fat loss together with increasing their size and definition of muscle mass.
The mainstream media may drive you into the panic of losing muscle if you don’t consume increased amounts of protein every couple of hours but muscle loss is reduced to minimum, if existent, when fasting undergoes. Fasting occurs when your body uses your own fat to derive the majority of its energy demands and its main focus encompasses repair, rejuvenation, detoxification and maintenance.
Starvation occurs when your body fat stores are depleted and energy is derived from muscle catabolism but even most lean people have enough body fat to go into prolonged fasting for weeks before starvation undergoes (Vlad Zot, C. 2015).
Working out before the eating window is ideal for someone who performs well during exercise on an empty stomach, while during the window is better suited for someone who doesn’t like to exercise on an empty stomach and after the window is for people who like to exercise after fueling but don’t have the opportunity to do it during the eating window.
Many studies have been done on intermittent fasting, in both animals and humans. These studies have shown that it can have powerful benefits for weight control and the health of your body and brain, it may even help you live longer.
However, you need to consult your doctor if you’re taking any medications, are pregnant, breastfeeding, or wish to become pregnant, or have a chronic condition, such as heart disease or diabetes.
References used for this article
Bragazzi NL, Sellami M, Salem I, et al. Fasting and Its Impact on Skin Anatomy, Physiology, and Physiopathology: A Comprehensive Review of the Literature. Nutrients. 2019;11(2):249. Published 2019 Jan 23. doi:10.3390/nu11020249
Mattson MP, Allison DB, Fontana L, et al. Meal frequency and timing in health and disease. Proc Natl Acad Sci U S A. 2014;111(47):16647‐16653. doi:10.1073/pnas.1413965111
Martinez-Lopez N, Tarabra E, Toledo M, et al. System-wide Benefits of Intermeal Fasting by Autophagy. Cell Metab. 2017;26(6):856‐871.e5. doi:10.1016/j.cmet.2017.09.020
Mitchell SJ, Bernier M, Mattison JA, et al. Daily Fasting Improves Health and Survival in Male Mice Independent of Diet Composition and Calories. Cell Metab. 2019;29(1):221‐228.e3. doi:10.1016/j.cmet.2018.08.011
Mizushima N, Komatsu M. Autophagy: renovation of cells and tissues. Cell. 2011;147(4):728‐741. doi:10.1016/j.cell.2011.10.026
Stekovic S, Hofer SJ, Tripolt N, et al. Alternate Day Fasting Improves Physiological and Molecular Markers of Aging in Healthy, Non-obese Humans [published correction appears in Cell Metab. 2020 Apr 7;31(4):878-881]. Cell Metab. 2019;30(3):462‐476.e6. doi:10.1016/j.cmet.2019.07.016
Vlad Zot C, Periodic Fasting: Repair your DNA, Grow Younger, and Learn to Appreciate your Food, 2015.