Intermittent fasting is a diet trend that is not going away any time soon — and for good reason! Healthy fasting can result in some pretty amazing health outcomes.
While many people tout the weight loss benefits of this dietary pattern and try fasting for fat loss, the health benefits of fasting extend far beyond better-fitting jeans. There are many intermittent fasting benefits and positive side effects that may surprise you.
Read on as we explore the health benefits of fasting, fasting science and ongoing research.
What is intermittent fasting?
Intermittent fasting is exactly what the name implies — foregoing food, for a period of time. While the word fasting may spark thoughts of going without food or water for days and feeling utterly famished, following an intermittent fasting routine can be quite manageable and is probably easier than you think!
Instead of focusing on which foods you should eat or skip, intermittent fasting dictates the time that you should be eating or skipping food — although you should still focus on consuming an overall healthy diet to reap the benefits. Combining intermittent fasting with a tried-and-true weight loss program like Jenny Craig’s Max Up can help you benefit from intermittent fasting and eating nourishing foods to support a healthy lifestyle and weight loss.
While there are many versions of intermittent fasting, many people start with a 14:10 schedule, as this approach can be easier for beginners. To follow a 14:10 intermittent fasting plan, you take a break from food and caloric beverages for 14 hours and nourish your body for the remaining 10 hours of the day. Since many of us sleep for at least eight hours a night, that leaves only six waking hours of fasting. For example, you may choose to eat from 8:30 a.m. to 6:30 p.m. and then refrain from eating until 8:30 a.m. the following day.
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Other versions of intermittent fasting include the 16:8 method (fast for 16 hours and eat for 8), the 5:2 method (eat normally 5 days a week and restrict your calorie intake to 500–600 calories for two days a week), and alternate full-day fasting. There are a slew of intermittent fasting variations that you can follow, but you might want to start with a more approachable version like 14:10.
When you are fasting, you are encouraged to maintain your hydration by drinking water, herbal tea and other non-caloric beverages. While eating during a fast is typically frowned upon, drinking calorie-free drinks is encouraged. Here’s exactly what you can eat or drink while intermittent fasting.
How does intermittent fasting work?
Intermittent fasting transitions your body between feeding and fasting states, and as a result, can cause your body to react in certain ways.
Fasting can impact certain hormones, and often in a positive way if you are trying to lose weight. Specifically, human growth hormone (HGH), which helps boost muscle mass and decrease body fat, can increase.1 Additionally, insulin sensitivity can improve, which can also result in fat loss.2
What’s more, when you fast, you are likely eating fewer calories than when you are eating whenever and wherever. Reducing your calorie intake, even if it is simply because you are limiting the hours that you eat, can help you reach your weight loss goals.
According to research, more than half of adults eat over a 15-hour window, with the bulk of their intake occurring later in the day.3 By following a structured plan like intermittent fasting, people tend to naturally reduce their caloric intake by limiting their eating “window” to a shorter time-frame.
Finally, intermittent fasting allows your body to follow your natural circadian rhythm that aligns with the sun and the moon. Your circadian rhythm is like your internal clock, letting your body know when it’s time to wake up and wind down. Research shows that it can be beneficial to eat and fast in accordance with this 24-hour cycle — eating when it’s light out and refraining from food when it’s dark (this is when you sleep!).4
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Following this natural pattern allows the body to undergo certain processes more efficiently. For example, fasting allows your body to rely less on glucose (sugars/carbohydrates) and more on your energy stores (fatty acids and ketone bodies).5 Using ketones for energy while you fast can support weight loss and other healthful outcomes such as reduced inflammation.5 Having a committed time to allow your body to switch from using glucose to ketones has been shown to be a positive practice.5
What are the health benefits of intermittent fasting?
When you consistently practice intermittent fasting, research suggests you may experience some incredible and exciting health benefits. Keep in mind, everyone’s results vary based on a multitude of factors including genetics, type of fasting schedule, diet, lifestyle practices and more.
Fat loss and weight loss
Many people attribute intermittent fasting to positive weight loss outcomes. Weight loss isn’t the only benefit you may experience when practicing intermittent fasting, but it is an important one.
Maintaining a healthy weight is linked to numerous benefits, including a reduced risk of developing certain cancers, Type 2 diabetes and heart disease.6 While weight loss diets continue to be a popular choice for many, intermittent fasting is becoming an effective alternative to shed some pounds.
Specifically, when evaluating adults who are overweight and obese, intermittent fasting appears to support weight loss in a sustainable way.7 Adopting the practice has been linked to a reduction in fat mass too.8
And if you want to lose fat and tone up, intermittent fasting might help. In one study, male athletes following a 16:8 intermittent fasting routine lost fat mass while maintaining muscle mass over a two-month period.9
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Improved blood sugar levels
In the past, experts would recommend that people managing high blood sugars, like those with diabetes, eat consistently throughout the day to maintain stable blood sugar levels. However, research is now showing that certain patterns of intermittent fasting could offer some benefits. In fact, according to a review published in the New England Journal of Medicine, intermittent fasting is linked to lower insulin levels and better blood glucose control.13
In some cases, intermittent fasting reversed insulin resistance while also resulting in weight loss and a reduction in the glycated hemoglobin level — implying better blood glucose control.14
Poor sleep, including not sleeping enough, is linked to adverse health risks, including obesity, Type 2 diabetes and certain cancers.15 And you’ve probably experienced first-hand what a lack of quality sleep can do to your mood.
This is because the timing of your meals (eating late at night) may interfere with your circadian rhythm and impact your sleep.17 So refraining from food and starting to fast a few hours before bed can help support your quest for a restful night, and help you reap all of the benefits of getting quality shut-eye.
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Chronic inflammation is linked to many diseases, including an increased risk of developing certain types of cancers.18 Research also suggests that as inflammatory markers in the blood increase, you may experience weight gain.19
Practicing certain versions of intermittent fasting has been shown to help reduce markers of inflammation naturally.20 Along with including other anti-inflammatory practices into your life like limiting refined sugars, managing stress, and eating plenty of non-starchy vegetables, following an intermittent fasting routine may help keep chronic inflammation at bay.
Reduced risk of cancer growth
Cancer is the second leading cause of death in the United States, making it a risk factor that many want to reduce.21
While many factors play into cancer development, including genetics, smoking practices, and stress management, intermittent fasting has been shown to potentially play a role in reducing the risk of certain cancers, specifically, by weakening the energy metabolism in cancer cells and thereby, slowing their growth and — in some cases — making them more sensitive to cancer treatments like chemotherapy.22
In one study on people with breast and skin cancer, combining a fasting-mimicking diet with chemotherapy resulted in the body producing more cells that help kill tumors.23
Other research suggests that intermittent fasting may help reduce breast tumor formation, possibly playing a role in reducing the risk of developing the disease.24
Is intermittent fasting right for you?
Whether you want to lose weight, drop inches from your waistline, reduce inflammation, sleep better, have better blood sugar control, or experience any of the other benefits that intermittent fasting has to offer, this dietary pattern can help support a multitude of health goals in a simple way. Combining intermittent fasting with a proven weight management program can help make intermittent fasting easier and more effective. Our newest and most effective plan ever — Max Up — gives you everything you need to include intermittent fasting into your life healthily and sustainably.
Learn how to start intermittent fasting along with eating delicious, nutritionally balanced, chef-crafted meals. Our science-backed program allows you to follow a 14:10 eating schedule with the help of a weight loss coach to set you up for a successful and enjoyable weight loss journey! Start Max today!
This article is based on scientific research and/or other scientific articles and was written and reviewed by certified professionals.
Our goal at Jenny Craig is to provide the most up-to-date and objective information on health-related topics, so our readers can make informed decisions based on factual content. All articles undergo an extensive review process, and depending on the topic, are reviewed by a Registered Dietitian Nutritionist (RDN) or Certified Nutritionist, to ensure accuracy.
This article contains trusted sources including scientific, peer-reviewed papers. All references are hyperlinked at the end of the article to take readers directly to the source.