Intermittent Fasting (IF) is more of a dietary pattern than a diet. Simply put it is an eating pattern that cycles between feeding and fasting. Sounds simple?
There is no real specificity to which foods are to be eaten and which are to be avoided, with the focus being on when you eat your food. In this respect, it is more accurately described as an eating pattern.
Common methods of IF involve daily 16-hour fasts or fasting for 24 hours, once or twice per week.
Fasting has been a practice throughout human evolution. Our ancestors didn’t have access to supermarkets or fast food outlets, and at times food wasn’t even available for them to hunt or gather.
As a result, the human body was able to adapt to be able to function optimally bothe physically and cognitatively without food for extended periods of time.
In fact, sporadic periods of fasting is more natural than eating 3 or 4 meals per day.
Common methods of Intermittent Fasting
There are many ways to conduct a fast, all of which contain a period of eating and a period of fasting. During a period of a fast, you eat very little or nothing at all.
However, Paul Jaminet, the author of the Perfect Health Diet has a valid argument for the consumption of coconut oil and bone broth during a fast.
Here is a list of the most popular methods
- The 16/8: Also known as the Leansgains protocol. It involves skipping breakfast and restricting your caloric intake to 8 hours, such as 12-8pm, then fast for 16 hours.
- Eat. Stop. Eat: This involves fasting for 24 hours, once or twice per week.
- The 5:2 diet: This method, you can consume up to 500 calories on two, non-consecutive days, then eat normally the other five days.
By reducing the total caloric intake over a period of time, all of these methods should lead to weight loss, so long as you’re not over compensating by overeating during your eating periods.
This can be avoided by eating natural whole foods such as, meat, seafood, eggs, vegetables, with some fruits and nuts.
Most people find the 16/8 method the easiest, most sustainable method to adopt. It is also the most popular.
How intermittent fasting affects your cells and hormones
During periods of fasting, several things happen to your body on a cellular level. For example, your body adjusts hormone levels to make stored body fat more accessible as an energy source.
At the cellular level, certain cells initiate important repair processes and change the expression of some genes.
Here are just some of the changes that occur in your body when you fast:
- Human Growth Hormone (HGH): HGH levels increase up to 5 times, this provides benefits to both muscle growth and fat loss.
- Insulin: Insulin sensitivity improves and levels of insulin drop dramatically. Lower insulin levels allow stored body fat to be more readily accessible.
- Cell repair: When in a fasted state, cells initiate cellular repair processes. This includes autophagy, where cells digest and remove old dysfunctional proteins that build up inside cells.
- Gene expression: Certain changes occur in the function of genes in relation to longevity and protection against disease.
These changes in hormone levels, cell function and gene expression are responsible for many of the health benefits of intermittent fasting.
There is a lot of science backed evidence showing the health benefits related to optimising weight control, the health of your body and brain. There are even some studies that suggest it may help you live longer.
Intermittent fasting and weight loss
Conventional wisdom discourages skipping meals, which is often associated with eating disorders and unsustainable crash diets. However, deliberately practiced IF, can be a powerful tool for weight loss.
Fasting involves caloric restriction. Sometimes, it easier to fast than to count calories.
Hormonal changes involved in fasting also promote weight loss, even if you don’t restrict calories. Fasting lowers the body’s levels of insulin, a hormone that prevents the release of stored body fat. With lower insulin levels, your body turns to stored fat for energy.
Here are some of the health benefits to intermittent fasting:
- Weight loss: As mentioned above, when performed correctly, it can be a healthy weight loss tool.
- Insulin resistance: This study showed that IF can reduce insulin resistance, which could prevent type 2 diabetes.
- Reduced inflammation: A key driver of many chronic diseases.
- Heart health: IF may reduce LDL cholesterol, blood triglycerides, inflammatory markers, blood sugar and insulin resistance. All risk factors for heart disease.
- Brain health: IF may protect against neurodegenerative diseases, such as Alzheimer’s.
- Cancer. Animal studies suggest that IF may prevent certain cancers.
- Anti-aging. Animal studies suggest that IF may extend lifespan.
Intermittent fasting and athletic performance
Initially, training in a fasted state might seem a bit contradictory. How can the body perform with fuel? Provided you’re not fasting for too great a period, IF can actually improve your athletic performance.
For endurance athletes, the benefits of fasting come from a two-pronged approach: training in the fasted state, and competing in the fed state. Fasted training can improve performance by forcing your body to adapt to lower glycogen stores and use glycogen more efficiently. Essentially, training in the fasted state adds another stressor, forcing your body to compensate and become stronger. This sets you up to get a huge boost from competing in the fed state.
Short-term fasting is also useful for power athletes. While fasting for several days at a time will hurt your progress, intermittent fasts less than 24 hours will not cause muscle loss or send your body into “starvation mode,” as long as you consume adequate calories and protein when you do eat.
On the contrary, when you lift in a fasted state, your body uses protein more efficiently afterwards, boosting muscle growth.
Weightlifters seeking to gain lean mass without also gaining fat should look into Martin Berkhan’s Leangains program, which specifies an eight-hour “feeding window” and a sixteen-hour fast every day.
Is intermittent fasting for everybody?
Like just about everything else in human nutrition, there is no one size fits all. This certainly applies to intermittent fasting.
For example, if you’re already underweight, pregnant, under heavy stress or have a history of eating disorders, a medical or health professional should be consulted prior to commencing a fast. In these scenarios, IF could actually have disastrous implications rather than be a benefit.
Some people just love food. There is nothing wrong with that. Enjoying traditional dishes from around the world can be a great experience. Bonus points if you’re sharing that experience with family and friends.
If you’re already eating a whole food diet, are generally more fat adapted, exercise moderately, have good sleep patterns, limit chronic stressors and are generally doing the things that make you happy then you’re probably in a good place to start playing with some fasts.
The bottom line
Basically, if you’re hungry, eat. Starving yourself only will cause additional stress.
If you’re already stressed, don’t IF. You don’t need another stressor.
If you’re completing high intensity training everyday, don’t IF. Unless you’re genetically gifted, you will need plenty of fuel to prevent overtraining.
If you’re not hungry, don’t eat.
Listen to your body. Try not to eat just because it’s midday and it is generally lunch time. At the same time, don’t feel guilty if you’re supposed to be in the middle of a fast and you’re reaching for a handful of macadamia nuts or some beef jerky. Try it out, skip a morning meal, sneak in a workout or go for a walk and see how you feel.
If you’re not ready, your body will tell you pretty quickly. Feeling lightheaded, reduced performance in workouts, cognitive decline or a general reduction in energy are all makers that you might need to fix a few things (food, sleep, stress, etc.) for a few weeks and try again.
In a perfect world, we’d all have an excellent metabolism, with a job we love and plenty of time to spend with friends and family. But unfortunately, it’s not and we don’t. We can, however, make the most of the world that we live in today.
Eat real food. Be active. Enjoy life.