Intermittent Fasting 101 … What is it and how does it work?
Have you been wondering about intermittent fasting? Did you know it’s not really a diet but a pattern of eating? Keep reading to learn more.
The history of fasting
Fasting is not a new concept. People have been fasting since ancient times. Humans have not always had daily access to food and were able to function for days without eating. Fasting was not a choice but a result of the lack of availability of food.
Fasting is also part of some religious rites. Some Christians observe Lent, between Ash Wednesday and Easter Sunday. Often during Lent something is “given up” usually a favorite food or drink. However, some choose to periods of fasting during this time.
Some Muslims take part in a month-long fast of Ramadan. Muslims are not allowed to eat or drink, not even water, between dawn and sunset.
For those of Jewish faith, Yom Kippur is one of the holiest days of the year. Some fast for a total of 25 hours, not eating or drinking anything.
What is intermittent fasting?
Intermittent fasting (IF) has become a popular “diet” for those hoping to achieve weight loss.
Actually, IF is not a diet but is an eating “pattern”. In other words, a cyclical pattern of eating and fasting over the course of a day.
There are three common IF schedules:
- The 16/8 cycle is probably the most popular. It includes fasting for 16 hours and eating during an 8 hour period. For example, eating only between the hours of 1pm and 9pm.
- The Alternating Days Cycle involves fasting for a 24 hour period followed by eating during the next 24 hour period.
- The Reduced Calorie Cycle includes maintaining a severely reduced calorie level of about 500-600 calories for 2 days and then eating normally for 5 days.
What are the benefits of fasting?
Fasting has been shown to have health benefits. It creates cellular changes in the body that includes hormonal changes and cell repair.
- Human Growth Hormone (HGH) is increased. HGH increases fat loss and builds muscle.
- Insulin is a hormone released by the pancreas. It allows the body to use sugar. When fasting, insulin sensitivity is improved and insulin resistance is reduced. Consequently blood sugar is better controlled enabling the body’s fat stores to be accessible and utilized.
- Norepinephrine is a hormone produced by the adrenal gland, which helps the body manage stress. Fasting increases norepinephrine levels which speed up metabolism. Consequently increasing the number of calories burned.
- During fasting, cells undergo a process of cell repair, removing accumulated dysfunctional proteins.
- There is evidence that there may be changes with gene expression during fasting which may relate to longevity or disease progression.
- When done properly IF can lead to weight loss. Much of this is due to an intake of fewer calories over fewer hours of the day.
- However, when compared to calorie restricted diets alone, IF led to decreased fat stores as well as weight loss.
- Unlike calorie restricted diets alone, IF also resulted in less loss of lean muscle mass.
- There is a risk of binge eating following fasting due to overwhelming hunger.
- Therefore, making sure to eat enough healthy calories during your feeding hours is critical.
- Exercising during fasting times is allowed and may help reduce hunger.
Download and print a Sample Intermittent Fasting 16/8 Meal Plan
You can start and stop your eating and fasting times to suit your schedule. For instance, if you are an early riser, you might start eating at 10am and stop at 6pm. Or if you are a night owl, start eating at 3pm and stop at 11pm.
The timing isn’t critical and can be adjusted to fit your lifestyle.
It’s not for everyone:
Obviously not every diet or way of eating is for everyone. IF may not be the right choice for you if you are underweight or have an eating disorder. Additionally, it is not smart to start a weight loss plan while pregnant or breastfeeding.
Further weight loss for someone underweight could be dangerous. IF will likely not provide enough calories and promote further weight loss.
Eating disorders can be difficult to manage. IF may lead to binge eating and further exacerbate eating issues.
In conclusion, it appears that IF is an effective alternative to a traditional calorie restricted diet. It has been shown not only to reduce weight but has additional health benefits as well. The risk of binge eating and overloading on calories during the feeding phase is something to be mindful of.