Intermittent fasting has been a hot topic as of late and is gaining popularity among the health and fitness industry. Research over the past several years has supported the idea of fasting at least one day, once a month.
The idea behind this is to stimulate your body's ability to utilize fat reserves for energy and to purge toxins by metabolizing them. People are now using it as a weight-loss method, improving their health and simplifying their everyday lives.
There are many studies (1, 2, 3)that show the powerful effects it can have on your body and brain. In fact, fasting may help you live longer. Keep reading to learn more about what intermittent fasting is and how it affects your body.
What is Intermittent Fasting (IF)?
Intermittent fasting is a cyclic eating pattern that switches periods of eating and fasting.
It's focus isn't on WHAT types of foods you should be eating, but rather WHEN you should be eating.
That being said, IF should not be considered a diet, but more of an eating pattern.
Throughout human history, fasting has been a part of our lives. This is based on our primal survival patterns of hunting and gathering. Even to this day, in less-fortunate parts of the world where there isn't a supermarket on every corner, people are going without food, sometimes days on end.
Fortunately, our bodies were designed to function without food for (reasonably) long periods of time.
Fasting has been a part of numerous different cultures and practiced for spiritual reasons for centuries (Christianity, Buddhism, Judaism).
Intermittent Fasting Methods
There are different ways to fast. All methods obviously utilize the splitting of time between periods of fasting and eating.
Here are the most popular methods:
The 16/8 Method: This method involves skipping breakfast and restricting your eating period to 8 hours. For example, only eating between 1pm-9pm. All other hours you are fasting.
Eat-Stop-Eat: This includes fasting for 24 hours, once or twice a week. For example, you wouldn't eat dinner one day until dinner the next day.
The 5:2 Ratio: With this method, you only consume 500-600 calories on two non-consecutive days of the week, but eat normally the other 5 days.
By reduction of caloric intake, you will lose weight as long as you don't over-compensate by gorging yourself during eating periods.
The method that is most-utilized due to it's simplicity and sustainability is the 16/8 method.
How it Affects Your Metabolism and Hormones
Naturally, this method of eating will affect your body. But how?
Your cells initiate important repair processes and your body makes adjustments to your hormone levels to make stored body fat more accessible.
Specific changes that your body makes include:
Insulin: Levels of insulin drop dramatically due to improvement in insulin sensitivity. Lower insulin levels make stored body fat more accessible (8).
Cellular Repair: When in a fasted state, your cells amp up cellular repair processes. How this benefits you is that your cells digest and remove old and dysfunctional proteins that build up. This sparks your body's ability to purge the old and replace with newer functional proteins, fostering a cleaner and more efficient metabolism (9, 10).
Everything listed above can be counted as health benefits of IF.
IF as a Powerful Weight-loss Tool
Less caloric intake means less transition of food into stored fat. And since IF changes hormone levels to facilitate weight loss, it's no wonder intermittent fasting is becoming more and more popular.
It's a WIN-WIN because as you decrease your caloric intake, you stimulate fat-burning processes.
One thing to remember is that you must NOT binge and eat massive amounts of calories during your eating periods.
Main Health Benefits
Weight Loss: The lowering of caloric intake and the boost in metabolic burn.
Insulin Resistance: This will protect against type II diabetes.
Reduction in Inflammation: Inflammation is a key contributor to many chronic diseases (13).
Increased Heart Health: Reduction in "bad" cholesterol (LDL), blood triglycerides, blood sugar and insulin resistance - all risk factors for heart disease.
Lower Risk of Cancer: Studies show that IF may decrease risk of cancer (14).
Brain Health: The brain hormone BDNF (brain-derived neurotrophic factor) may stimulate the growth of new nerve cells and may also protect against Alzheimer's disease (15).
Anti-aging Potential: IF can potentially extend lifespan (16).
Keep in mind that the science on all of this is still in its preliminary states.
There's nothing inherently dangerous about IF while you're an overall healthy and well-nourished individual. However, as with any modifications to your diet, there can be risks involved. These risks are dependent on your current health status and chronic issues you may already be facing.
Weakness and hunger are obvious side-effects of fasting due to the fact that you are depleting yourself of the caloric intake that you normally provide yourself. That being said, you should ALWAYS CONSULT YOUR PRIMARY CARE DOCTOR before making any changes to your diet, ESPECIALLY if you are on a prescription medication regimen.
I hope I've answered any questions you may have had. Or, maybe opened your eyes to some new information that you may not have known about. Either way, knowledge is power and I hope that I've contributed to your pool of knowledge.
Please comment with any insight or experiences that you may have had with intermittent fasting. Also, please share with those you feel may be interested in the topic. Thank you for reading and always, be hard to kill out there!