If you’re a regular reader, chances are you’re always looking for ways to improve your diet, maximize nutrition intake and, of course, maintain a healthy weight. You’ve also probably heard of intermittent fasting and wondered if it could benefit you.
This type of fasting isn’t really a diet but a method of cyclical eating with defined fasting periods ingesting few or no calories followed by set windows of time during which all daily food and drink are consumed.
It can be a challenge trying to change a lifetime’s worth of eating habits, but here are some of the many evidence-based advantages that might make it worthwhile.
- Rev up your metabolism
- Kick start weight loss, particularly belly fat
- Improve blood pressure
- Help prevent Alzheimer’s
- Increase your lifespan
How difficult is fasting?
Although there are still a lot of people who are shocked by the idea of going without food for prolonged periods, fasting is a very natural process. In fact, you’re probably completing daily fasts right now.
Fasting is defined as the absence of food. Most people, when they go to sleep at night, do not wake up to eat. So just going to sleep means you’re completing a 7–10 hour fast. Since many of us eat a couple hours before bedtime, add another 2-3 hours and you’ve already fasted for 9-13 hours without even trying.
Types of intermittent fasting
There are many different versions of intermittent fasting. This makes it easier to find one that suits you. Below are 5 popular options and how they work.
This method involves a 16-hour fast with a feeding window that is 8 hours long. For example, you might eat your first meal at 12pm and your last meal at 8pm daily. The fasting period would last from 8pm in the evening to 12pm the next day, which is total of 16 hours. This type of fast is completed daily.
Some people use a slight variation, fasting for 14 hours and eating during a 10-hour window. Others fast for 18 hours and eat for 6.
- Pretty easy to implement especially if practitioners simply skip breakfast in the morning and eat their first meal at 12pm.
- No food restrictions. Fasters can eat any type of food.
- Can work with any schedule as the faster can pick any 8-hour window during a 24-hour cycle.
- Must stick to consistent timing or hormonal balance may be affected.
- Women are particularly susceptible to reproductive issues with longer fasts.
- Anyone who naturally skips breakfast.
- Men vs. women – although some women do just fine, they are more sensitive in general to the risk of hormonal imbalances.
- Although there are no restrictions, it is usually easier to eat 2-3 meals during the eating window.
- Women using this method may wish to start with a 14-hour fast and build to 16 hours or more over time.
- On exercise days, focus on higher carbohydrate meals. On other days, lower carbohydrate intake and increase fats.
- Protein should be the main component of the diet.
This method involves a 20-hour fast with a feeding window that is 4 hours long in the evening. You eat one meal between 4pm and 8pm daily. The fasting period would last from 8pm in the evening to 4pm the next day, which is total of 20 hours. This type of fast is completed daily.
- Daily fasting has a positive effect on insulin resistance.
- Allows raw fruits and vegetables in small amounts during the day.
- Challenging to go 20 hours without a full meal.
- Scheduling may be difficult since the eating window is specific.
- Strict food guidelines require more planning and make it more difficult to sustain over time.
- Anyone who likes to have their biggest daily meal in the evening.
- Detail-oriented types with the time and dedication to stick to all the various requirements.
- Plan as far ahead as possible.
- Start with a shorter fasting period and slowly build up to 20 hours.
There are 2 common variations of this method. The first requires eating one meal each day at the same time. The second variation requires the 24-hour fast 1-3 times per week.
- Simple to implement. Just eat a large meal once per day.
- No counting calories.
- No food restrictions.
- Difficult to develop a habit of eating once per day.
- May lead to overeating and poor food choices.
- People with strong self-discipline.
- People who don’t want to think about counting calories or restricting portions.
- Make sure to remain hydrated during the day.
This diet requires eating normally 5 days per week and eating no more than 500 calories (600 for men) for the other 2 days. Another variation is eating less on alternate days. For example, eat normally on Monday then consume no more than 500 calories on Tuesday. Continue alternating each day.
- Easy to follow.
- May encourage a binge and purge approach to food.
- People who don’t have issues with binge eating.
- People who can switch back and forth easily between diets.
- Plan ahead for fasting days.
There are various versions of this fast.
One is simply eating every 36 hours. If you eat dinner at 7pm on Monday, your next meal would be breakfast on Wednesday at 7am. Another version requires 1 36-hour fast per week, 1 cheat day and some form of intermittent fasting during the rest of the week.
- Cheat day.
- Extremely complicated and challenging to follow.
- People who need cheat days.
- People without health issues.
- A 36-hour fast is pretty intense and should not be undertaken without consulting a healthcare provider.
Which one should you choose?
Although the many variations of intermittent fasting can seem overwhelming, any version will be effective as long as you choose one that suits your lifestyle, goals and temperament.
Whichever one you eventually choose, keep these points in mind to increase your odds of success.
- Make sure you drink enough water every day. Hydration is important for keeping hunger at bay, preventing headaches, and avoiding brain fog.
- Start slowly and build up gradually. Develop your fasting ability over time, starting with shorter fasts and eventually going for longer periods.
- Plan ahead until fasting becomes a habit. Keep busy during your fasting hours so you’re less tempted to cheat.
- Consistency is key.
Don’t get discouraged and don’t give up. Lasting benefits require a long-term approach.