Intermittent Fasting: The Science Behind It and Its Health Benefits

If you’ve been considering changing your diet, whether to increase your overall health or to lose weight, you’ve likely come across the concept of intermittent fasting. A relatively trendy diet, intermittent fasting (also called IF) has gained a large following. However, unlike many trendy diets that don’t really contribute to major health benefits beyond helping you drop a few pounds—and then leaving you on your own to ensure you actually keep those pounds off—IF is an emerging tool in reducing the risk of some chronic diseases.

Just like your body will thank you for regular exercise, high-quality sleep, proper stress management, and a nutritious diet, it will also thank you for making the change to an IF diet—and making the switch to IF is easier and simpler than you think.

What Is Intermittent Fasting?

Whether you want to use intermittent fasting to lose weight or just to make a healthy change, it’s important to begin the process by defining IF; what exactly is intermittent fasting? According to Johns Hopkins Medicine, intermittent fasting isn’t so much of a diet as it is an eating plan that focuses on when you eat. The goal is to not eat at all for a certain number of hours each day, or to limit the number of calories you eat per meal for two days per week. This plan, studies have shown, can lead to not only weight loss, but a range of health benefits.

How Does Intermittent Fasting Work?

So, why does this seemingly simple change actually work? Johns Hopkins further explains that, biologically, your body has evolved to not eat for long periods of time. Your prehistoric ancestors didn’t have food on demand; in some cases, they had to wait for extensive periods of time between meals. To keep these ancestors alive, the human body learned to burn existing fat when it wasn’t getting regular food.

For better or worse, you rarely need to wait that long between meals or snacks anymore which means that your body is constantly burning your last meal—never your fat stores. When you switch to an IF lifestyle though, you give your body enough time between meals that it must start burning fat for your own survival. This fat burning helps you lose weight without forcing you to add any extra exercise to your routine.

What Are the Health Benefits of Intermittent Fasting?

Beyond intermittent fasting weight loss, IF comes with additional health benefits.

Certified nutrition specialist, licensed dietitian/nutritionist, and Arootah consultant Alesia New notes that, of the few published limited human studies, IF has been shown to benefit verbal memory improvements. Meanwhile, animal studies have revealed benefits such as working memory improvement, tissue health improvement, and reduced risk for diabetes.

We previously detailed that limited studies have shown how IF can improve brain health, by lowering blood pressure, improving insulin sensitivity, and reducing the risk of obesity.

However, Johns Hopkins has also identified animal studies that show that IF can improve resting heart rates as well as other cardiovascular measurements of health. In another study, Johns Hopkins stated that young men who followed an IF diet could lose fat while still retaining muscle mass.

Who Should or Shouldn’t Try Intermittent Fasting?

IF isn’t for everyone. Be sure to talk with your healthcare provider before beginning a new health program, including IF. Some individuals should steer clear of the IF lifestyle for their overall health, cautions New, including those who:

• Are currently underweight and need a higher caloric intake
• Are under the age of 18
• Are pregnant and/or nursing

However, IF could prove to be particularly beneficial for people dealing with:

• Obesity
• Type 2 diabetes
• Metabolic syndrome

If you do begin to experience out-of-the-ordinary anxiety, headaches, nausea, or other strange symptoms after beginning an IF lifestyle, Johns Hopkins Medicine recommends speaking with your doctor as soon as possible.

How to Get Started with Intermittent Fasting

If you think you fall into one of the safe categories for adopting the IF lifestyle, first, get started by talking to your healthcare provider. Any serious weight loss program should be discussed with a provider, as they can take your individual health needs into account. Once they give you the green light, it’s time to choose an IF plan.

There are three IF plans:

• Intermittent fasting 16/8
• Intermittent fasting 5/2
• Alternate day fasting (or ADF)

With intermittent fasting 16/8, you fast for 16 hours every day, only drinking water, black coffee, or tea during those hours, and then you can eat for the remaining eight hours. You should focus on avoiding processed foods during the window in which you eat.

For the 5/2 plan, you eat as you would regularly eat for five days and then, for two days of the week, you limit your caloric intake to 500 to 600 calories, all consumed in one sitting, still focusing on avoiding high-calorie, low-density, and processed foods.

The ADF plan is the simplest, as there’s no timing or calorie counting to get right; you simply fast completely, every other day.

While the ADF plan may seem the most difficult or dramatic change (and Johns Hopkins cautions this one may be dangerous for some individuals), that doesn’t make IF difficult overall. For many, the 16/8 plan is incredibly doable, while the 5/2 plan is even more so.

The Bottom Line

Intermittent fasting is an emerging health tool, but—just like regular exercise, quality sleep, stress management, and a nutritious diet—it has proven valuable in preventing the risk of some chronic diseases. More importantly, it’s an incredibly simple diet change that your body will thank you for making.

Need support making healthier choices? An Arootah coach can help you identify and solidify your goals while holding you accountable to take the steps needed to meet them.