Intermittent fasting (IF) is a term that has become quite popular lately. Many people are talking about and many people are trying to do some form of IF. In all cases, this term refers to the practice of abstaining from food for varying periods of time and varying intervals. Many different health benefits are attributed to some type of fasting. But a word of caution here before going any farther. For anyone who has struggled with an eating disorder, fasting can be a trigger back into that vicious cycle and is NOT recommended unless done under the supervision of your personal health care provider. It’s important that fasting be conducted properly or it can also make you very sick. So for anyone thinking about any kind of fasting that involves more than 2 days of not eating, it’s very important to make sure you talk that over with your healthcare provider before getting into it. Let’s look at some of the most popular forms.
5:2 Fasting
This refers to fasting for two non-consecutive days out of every week. Some people eat nothing and just drink water those two days. Many more people eat a very calorie restricted diet on the two days and then anything they want on the other 5 days. On the fast days, women are restricted to about 500 calories and men to 600 calories. If you are doing this to lose weight, it’s important to eat normally the other 5 days, and not eat more calories than you ordinarily would. So, for example, someone might choose to make Monday and Thursday their low calorie days and then eat normal meals on the other days of the week. This does decrease total calories consumed every week and can help some people to lose weight. But the emphasis is on WHEN you eat, not WHAT you eat.
16:8 Fasting
This refers to the practice of having a “window” of time out of every 24-hour period when you eat your meals. Then nothing is eaten the rest of the 24-hour cycle. The “window” here would be 8 hours out of every day when you would eat. This window should be the same every day. An example would be having breakfast at 8 and finishing eating by 4 in the afternoon, giving you 16 hours with no food intake. Many people eat whenever they wish within this window, not always having regular meal times but maybe a breakfast followed by intermittent snacks and a bit more of a meal as they near the end of their eating window. Many of the benefits of IF are seen as long as the fasting time is longer than 12 hours. But some people might even make their eating window 6 hours with 18 hours of fasting. The longer the fasting time, the longer the body is in ketosis before the eating window begins. Some people find this helps them to lose more weight. An advantage to this approach is that a significant portion of the fasting period is while you sleep, making it relatively easy to maintain the fast.
Fasting-Mimicking Diet
This diet consists of periodic short fasts that are not total abstinence from food but taking in limited calories in a very particular balance of macronutrients. Often this fast is for 5 days out of a month and sometimes repeated over several months. Most of the research on this type of fast comes out of the Longevity Institute at the University of Southern California and the name most people associate with these studies is Dr. Valter Longo. His work has been an attempt to get many of the positive effects of water fasting without the dangers and difficulty of extended water fasts. On the first of the 5 fasting days, the diet is just over 1000 calories of which 10% come from protein, 56% from fat, and 34% from carbohydrates. On the second through fifth days total caloric intake is about 725 calories, of which 9% come from protein, 44% from fat, and 47 per cent from carbohydrates. Usually there are soups and broths to increase volume of the food without increasing the calories. This has been extensively tested on lab mice and very promising results for both longevity and the control of metabolic disorders such as a diabetes. Early research on human subjects is also very promising. For more details on the benefits of fasting you can check out my article on “What are the Benefits of Fasting?”
The True Fast
In the book Counsels on Diets and Foods I came across this type of fast. Although it is not intermittant, it still is an important type of fast to consider, quite possibly in combination with one fo the other fasts described above. Here the True Fast is defined as “abstinence from every stimulating kind of food, and the proper use of wholesome, simple food, which God has provided in abundance.” So here we see that a simple healthful diet on a daily basis is also a kind of fast that can contribute to better health. It is “fasting” or abstaining from anything which works against our health, whether that be refined and processed sugars, alcohol, tobacco, or caffeine. In a society where people are used to “rewarding” themselves from time to time by indulging in something that they know is less than ideal for their health, this is indeed a revolutionary idea. This constitutes a real commitment to optimal health but the rewards are rich indeed and paid back in not only health of body, by clearness of mind, optimism, and longevity.
So you can see that fasting is a rather broad term that can refer to different approaches to structuring food intake. Most people will benefit greatly from practicing the True Fast, which reflects intentionality in food choices and being aware of best practices for health. We will explore the benefits of intermittent fasting in the next post, so stay tuned!
References:
https://www.medicalnewstoday.com/articles/321690.php
https://www.quora.com/What-is-an-example-of-fasting-mimicking-diet
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5388543/
Counsels on Diet and Foods by E.G.White
