How to Use Intermittent Fasting for Weight Loss

If you’re someone who has struggled to lose weight, the chances are good you’ve heard something about intermittent fasting. It’s one of those terms that’s everywhere, and yet it’s also frequently misunderstood.

The word “fast” can bring up bad associations. As a rule, it’s not a good idea to deprive your body of food. And a fast, by definition, is a period during which you don’t eat.

That said, intermittent fasting is not unhealthy. In fact, it may be an effective way to lose weight and – even more importantly – maintain a healthy weight. So, let’s talk about what intermittent fasting is, how it works, and how you can use it to lose weight.

intermittent fasting for weight loss

What is Intermittent Fasting?

Let’s start by talking about what intermittent fasting is. Basically, it consists of alternating periods of fasting (abstaining from food) and eating. The cycles may occur daily or weekly and there is more than one way to engage in intermittent fasting.

Most people naturally fast for part of the day – most often, when they’re asleep. For example, if you finished dinner at 7:00 PM and didn’t eat until breakfast at 7:00 AM the next morning, you would have fasted for a total of 12 hours.

Most variations of intermittent fasting prohibit food during the fast but allow you to drink beverages that don’t have any calories. These include water, coffee, and tea. There are some variations that allow moderate caloric intake during the fast, but for the purposes of this article, we’ll focus on true fasting.

will coffee break a fast

The idea of fasting may be a daunting one for some people. Most of us don’t like the feeling of being hungry and we assume we’ll be very hungry during a fast. However, many people who do intermittent fasting report that once their bodies adjust, they don’t feel hungry and have more energy than they did without intermittent fasting.

Methods of Intermittent Fasting

There are several popular methods of intermittent fasting. That’s good news because it means you can choose the method that best suits your body and lifestyle. Here they are:

  1. The 16/8 method. This method involves fasting for 16 hours per day and eating in an 8-hour window. For example, you might fast from 8 PM to 12 PM the next day, then eat two or three meals between 12 PM and 8 PM. Some experts suggest that 16 hours may be too long for women.
  2. Alternate Day Fasting. This method involves fasting for 24 hours and alternating with normal days of eating. For example, you could have dinner at 7 PM one night and then have nothing but non-caloric liquids until 7 PM the next night.
  3. The 5:2 diet. This version involves fasting five days a week – which in this case means restricting your calorie intake to between 500 and 600 calories and eating normally the other two days. It’s also known as the Fast Diet.
  4. The Eat-Stop-Eat method. This version of intermittent fasting involves 24-hour fasting two times a week and eating normally the rest of the time.
  5. The Warrior Diet. This diet involves fasting most of the day (the original plan allowed for small amounts of vegetables during the day) and feasting at night. Most of your eating happens in a four-hour window at night.

For most people, fasting for a full 24 hours at a time may be too much. It means that you’ll likely be very hungry and that can impact your comfort, energy levels, and even your mental wellbeing.

It’s important to note that any prolonged period of fasting (10 hours or more) can be beneficial to your health. A lot of people do very well with a 12 or 14-hour fast.

What Are the Health Benefits of Intermittent Fasting?

There are significant health benefits to intermittent fasting. It’s important to be informed before you begin, so here’s what you should know.

  1. Intermittent fasting can help you lose weight. One study looked at obese women who engaged in intermittent fasting. It found that overall, the study participants lost more weight, lost more visceral (belly) fat, and had lower cholesterol than the women in the control group.
  2. The same study found that intermittent fasting reduced the women’s risk of cardiovascular disease significantly. That may be due in part to the reduction in LDL cholesterol, but their heart rates also slowed.
  3. A study from 2004 found that intermittent fasting improved brain function in adults. It also reduced their blood pressure.
  4. That same study found that intermittent fasting had a positive impact on insulin sensitivity and could be a factor in treating and reversing Type II diabetes.
  5. Another study confirmed those results, concluding that intermittent fasting could decrease insulin dependence and lower blood glucose levels.
  6. Intermittent fasting may help to combat oxidative stress, which contributes to many diseases associated with aging.
  7. Intermittent fasting stimulates autophagy, which is a form of cell regeneration. For that reason, it may protect us against some kinds of cancer.
  8. Finally, a study found that intermittent fasting may protect your brain and prevent neurodegeneration, including dementia and Alzheimer’s disease. Specifically, it releases chemicals that improve cellular stress response.

how to lose weight with intermittent fasting

As you can see, there are significant health benefits to intermittent fasting.

Why Is Intermittent Fasting Effective?

Why is intermittent fasting an effective method of weight loss? There are several reasons.

  1. Your insulin levels decrease dramatically when you fast. Research has shown that when insulin levels are low, we burn more fat than we do when they’re high. On a related note, insulin resistance is a big problem in overweight people. Fasting can help restore your insulin sensitivity and help you lose weight.
  2. Your levels of Human Growth Hormone (HGH) tend to increase when you fast. Studies have shown that high levels of HGH are directly correlated to fat loss. Reduced levels of HGH, by contrast, have been linked to a decrease in lean body mass.
  3. During a fast, your nervous system releases a hormone called norepinephrine, which is responsible for breaking down body fat so your body can burn it for energy.

In other words, intermittent fasting prompts your body to burn fat by reducing your insulin levels, releasing Human Growth Hormone, and releasing norepinephrine. It may also improve sleep by helping to regulate circadian rhythms. Multiple studies have shown a correlation between insomnia and weight gain.

better sleep with intermittent fasting

How to Use Intermittent Fasting to Lose Weight

Now, let’s talk about how you can use intermittent fasting to help you lose weight.

#1: Pick an Eating Window That Works for Your Schedule

The first step is to choose an eating window that works for your lifestyle and schedule. If you’ve never tried intermittent fasting before, you’ll probably want to stick to a daily fast instead of attempting to go 24 hours without food. The 16:8 method is the most popular.

If you work away from home during the day, you may want to try fasting from 7 PM to 11 AM. That way, you won’t need to get too far into your workday without food.

#2: Decide on the Rules of Your Fast

As we mentioned before, some fasts allow minimal caloric intake while others call for nothing but non-caloric beverages during the fast period. You can certainly drink all the water, coffee and tea you want – but there are a few caveats.

For example, caffeine has a direct effect on your adrenal system. Drinking caffeinated beverages without food in your stomach may make you feel jittery. It can also increase your hunger.

Benefits of Intermittent Fasting

Likewise, artificially sweetened beverages can spur an insulin response in some people – the same way drinking a sugary soda or a glass of juice would. It may be best to avoid them if your goal is to lose weight.

#3: Pay Attention to Your Body

The most important thing to do as you begin intermittent fasting is to pay attention to your body. It may help to keep a food journal. Some foods may play a direct role in how hungry you feel during your fast. For example, if you eat sugary foods that cause your insulin to spike, you may find yourself getting intense hunger pains a few hours after you eat.

Keeping track of your food can help you figure out an eating plan that works for you. You may find that eating a protein-rich meal right before your fast helps keep you from feeling hungry during your fast.

If you’re uncertain or have questions about how your body is responding to the fast, check-in with your doctor or a certified nutritionist to get some guidance on how to proceed.

#4: Track Your Weight Loss

Not everybody reacts to intermittent fasting the same way. Weigh yourself regularly and keep track of what you’ve lost. If you find you’re not losing weight – or you’re losing weight too rapidly – you may need to change your diet accordingly.

Calorie Counting

It’s also worth noting that you should be careful to eat a nutritionally balanced diet that provides the macronutrients and micronutrients you need. Intermittent fasting is not meant to be a starvation diet and your body still needs healthy food.


There’s plenty of evidence to suggest that intermittent fasting is a reliable way to lose weight. If you decide to try it, make sure to listen to your body and give it what it needs.