Intermittent Fasting Facts: Potential Benefits, Risks, and Side Effects

Published on: February 16, 2023
Intermittent fasting

Intermittent fasting has taken the world of nutrition and fitness by storm. This is a time restriction pattern of eating that limits when you eat- not what you eat.

It’s different from other types of nutritional interventions, such as dietary and caloric restrictions. Dietary restriction limits what you can and can’t eat. Caloric restriction means a reduction in the number of calories you can eat.

If you’re interested in joining the bandwagon, here is a list of interesting facts about intermittent fasting.

It’s Not New

Fasting did not begin yesterday. It’s thought to have been a part of life since the start of humankind. Tens of thousands of years before agricultural innovation, our early ancestors depended on hunting and gathering. Back then, it’s arguable that eating three meals a day was practically challenging.

Even after food became abundant, fasting has been at the center of different religions, societies, and cultures for years.

Fasting was considered a form of purification and a source of strength among the ancient Greeks. It was their culture, for instance, to go on a water fast when preparing for the Olympics. Hippocrates, one of the greatest Greek physicians, once said, “fasting is the greatest remedy – the physician within.” Pythagoras also swore by it, claiming it cleared his mind and gave him strength.

Modern intermittent fasting has been experimented on animals since the 1940s. But it’s safe to say that it was popularized by Martin Berkhan- a fitness veteran practicing IF since 2006.

Various Ways to Do It

Intermittent fasting is a term used to refer to different meal-timing schedules. These schedules vary in the length of fast hours and calorie restriction. That said, there are various fasting styles to suit different people’s lifestyles, health, and dietary requirements.

The 16/8 fasting plan is one of the most preferred types of intermittent fasting. It combines a 16-hour fasting period with an 8-hour eating window. With the 16/8 approach, you can schedule so that a large part of the fasting window falls at night while sleeping.

If fasting for 16 hours seems daunting, the 12-hour intermittent fast might be easier. This plan involves fasting for 12 hours. For instance, if you eat breakfast at 6 AM, your next meal will be at 6 PM. Another example is eating dinner at 7 PM and abstaining from food until 7 AM the following morning.

The 5:2 is another highly recommendable fasting method for IF newbies. This is a calorie-restricted fasting plan. You eat normally for five days and cap your calorie intake to 500 (women) and 600 (men) calories on two non-consecutive days. When fasting, you can spread your calorie intake throughout the day. Most people consider this the best intermittent fasting plan because it doesn’t have a distinct non-eating period.

It Doesn’t Have to Be Hard

Studies continue to prove that IF can effectively tackle health issues like obesity, diabetes, and cancer. But flipping the switch from eating several meals per day to fasting seems impossible for most people. However, experts say that some intermittent fasting approaches, like the 16/8 and the 12-hour plans, are sustainable and effective.

On top of that, there are many helpful ways and tools to make intermittent fasting easier. Adding green tea, water, and a fiber supplement to your diet can help curb cravings and appetite. An app like is another helpful tool that offers its users science-backed insights on achieving the best results from intermittent fasting.

Intermittent Fasting and Weight Loss

One major reason intermittent has become so popular is its benefits for weight loss. There are different ways intermittent fasting can help with weight loss:

  • It forces your body to burn fat- intermittent fasting works by stretching the time between meals. Doing this forces the body to tap into the stored fats after depleting the available glycogen, thus promoting weight loss.
  • Fasting reduces calorie intake- by restricting when you eat, intermittent fasting ensures you’re not adding more unnecessary calories to your system. Reduced calorie intake leaves your stored fats as the logical energy source to turn to.
  • It enhances metabolism- fasting for a prolonged period is linked with lowered metabolism. But now, a study proves intermittent fasting can boost metabolism by 14%. If you’re having difficulties losing weight, speeding up your metabolism might help you get over the hump.

Intermittent Fasting and Diabetes

Active studies suggest intermittent fasting can help control blood sugar levels and improve insulin sensitivity. Actually, there are several case series of type 2 diabetes patients who have achieved diabetes remission and even stopped insulin therapy. The 16:8, 5:2, and alternate-day fasting are the most popular intermittent fasting plans for diabetes.

Every patient has different needs and considerations. If you’re interested in trying intermittent fasting for diabetes, discuss it with your doctor first to ensure it’s safe.

Intermittent Fasting and Cancer

Studies on whether IF can help manage cancer are still in their early stages, but the available results are promising. In one small study involving breast cancer patients, the researchers found that intermittent fasting helped activate immune marker genes. The researchers explain that the immune system was beginning to recognize cancer cells as something it should fight.

Intermittent Fasting Has its Risks and Side Effects

Intermittent fasting may be safe for most people. But that doesn’t mean it comes without its risks and side effects. Here are the most common side effects and dangers of intermittent fasting to consider before trying:

  • Hunger pangs and cravings
  • Digestive issues like constipation, diarrhea, and bloating
  • Headaches. These are thought to be caused by dehydration, caffeine withdrawal, and low blood sugar levels
  • Fatigue and tiredness
  • Mood changes characterized by irritability, aggression, and difficulty concentrating
  • Sleep difficulties as your body tries to adjust to the new schedule

It’s Not for Everyone

Considering all the risks and side effects above, it makes sense that intermittent fasting is not for everyone. You should not try intermittent fasting if:

  • You are underweight
  • You have a history of eating disorders
  • You have sleep problems
  • You have type 2 diabetes and need to use insulin
  • You are pregnant, trying to conceive, or breastfeeding
  • You are trying to build muscle mass
Was this article helpful?

The information provided on this website, including text, graphics, images, and other materials, is intended solely for informational purposes and should not be used as a substitute for professional medical advice, diagnosis, or treatment.