Fasting is not a new concept to human biology.

Our bodies were designed to handle periods of food scarcity by using something called metabolic flexibility, which is our body’s ability to switch energy sources when one source is low. Our most immediate source of energy is the calories we consume, the fats and carbohydrates in our diet. When we burn through those, we have fat stores. Then, we have amino acids that can also be converted to glucose for energy use.

But in our modern society, most people don’t face food scarcity.

We don’t burn through all the energy available from our caloric intake, so what happens?

The calories remaining are stored as fat for later use—a use we won’t likely ever get to. This is how we gain weight. We’re not going through our energy thoroughly enough for metabolic flexibility to switch systems and deplete our fat stores.

So how do we break the storage cycle to regain our metabolic flexibility?

We fast. Studies are beginning to show that short, periodic fasting practices can reset your body to burn those fat stores and use your natural metabolic flexibility functions. In fact, the jump start to your fat burning machinery can be more significant than traditional calorie restricting nutritional approaches. Initial testing on intermittent fasting is showing a plethora of benefits:

• Reducing blood pressure, stress levels, cholesterol, and overall disease risks such as diabetes and heart disease

• Improved control of blood sugars, cardiovascular function, and appetite

• Increased fat burning, metabolic rate (not immediate, but in the longer term), growth hormones, and cellular repair.

But intermittent fasting’s benefits don’t stop there. There are psychological benefits that people are surprised to learn.

1. Hunger is not an emergency

What happens when we skip a meal? There’s a hunger pang that can trigger a panicky feeling. This is ingrained; it’s our stomach’s way of reminding us we typically eat again this many hours after our last meal. But skipping a meal doesn’t result in muscle loss, imbalance of body systems, or a true emergency. We were designed to handle hunger. It’s not catastrophic to miss a meal, and doing so can jumpstart our body’s metabolic flexibility. “Oh, my caloric energy source has dried up. There’s fat stored over here, so I’ll burn that instead.”

2. Physical Hunger vs. Psychological Hunger

We also experience physical and psychological hunger. Fasting allows us to learn the difference, what real hunger feels like. It’s not a bad idea to let that feeling percolate, recognize it for what it is, and use that knowledge to realize when you’re truly hungry or just have an urge to snack. At the end of a fasting day, you’ll know what true hunger feels like, so when psychological hunger strikes, you won’t be fooled.

3. Not Everyone Eats Regularly

There are people in America for whom three meals a day isn’t possible. They’re not starving, but there’s not enough to go around. They may skip meals to put their children’s nutrition first, and even then, that might not be enough. With the help of food banks, charities, and government programs, they can get by, but one thing is certain: they don’t take food for granted. Knowing what real physical hunger feels like can help us appreciate those for whom intermittent fasting is not a choice.

4. Eating is Not Just a Privilege, but a Responsibility

Knowing true hunger can help us respect the food we have access to and make it easier to prioritize nutrition over junk. Why pick the nutritiously devoid option when we have access to the healthier option?

5. Food Advertising is Subconscious

Food marketing is everywhere, but we’re never more aware of it than when we’re fasting. This awareness shows how ubiquitous and subtle food companies are in pushing their message on us. By becoming aware of pervasive food advertising, we begin to see all the micro-manipulations food companies use, and in turn, are better able to resist.

Intermittent fasting is just that: intermittent. It has the power to show us the importance of food, and place a stark light on our nutrition mentality. Fasting for one day makes us see what real hunger is, jump starts our bodies’ biological systems, and improves our mental awareness of what food means to us and how we are conditioned by outside forces to view food. Once we get past the idea that skipping meals = bad for us, we can see that really, it’s what our bodies were designed to do.