Fasting is nothing new—cultures around the globe use it as a way to reset the body and mind in order to be spiritually cleansed. It’s also a surprisingly effective way to lose weight, particularly if you’re trying to achieve metabolic flexibility.
According to Harvard Health, while many people find it difficult to fast, promising research (in rats) suggests that if you can figure out a way to make intermittent fasting work for you, you’ll see safe and quick results. The key, of course, is to make sure that you get plenty of nutrients even when you’re abstaining from food.
Intermittent fasting is gaining pop culture acceptance
Intermittent fasting as a diet—rather than as a religious tool—has been gaining popularity since 2012. “Dr. Michael Mosley’s TV documentary Eat Fast, Live Longer and book The Fast Diet, followed by journalist Kate Harrison’s book The 5:2 Diet based on her own experience, and subsequently by Dr. Jason Fung’s 2016 bestseller The Obesity Code” are three of the most popular books or documentaries on the subject.
These diet books suggest that while it’s still important to eat plenty of fruits, vegetables, fiber and other nutritious food, taking a break from eating is effective in helping you lose weight.
The science behind intermittent fasting
Our bodies use food as fuel for energy. Eating carbohydrates gives us a quick burst of energy, but when we take a break or use diets like keto to induce fat burning, our bodies stop relying on insulin release from carbs and instead start breaking down fat tissue as fuel. When that happens, we see very quick weight loss.
Intermittent fasting is a key tool in achieving metabolic flexibility, or rather, training your body to burn off whatever food you give it instead of storing it as fat tissue. Once your body achieves metabolic flexibility, it’s much easier to lose weight and keep it off over time.
Exercise is the other key way to achieve metabolic flexibility, especially high intensity cardio on an empty stomach. The body is forced to burn fat to power through workouts.
If you’re taking in a big portion of calories during the night, you’re far more likely to store that energy as fat tissue. That’s why diets like the 16/8 fast (confining eating to 8 hours per day) and the 5:2 diet (two days of fasting per week) helps “dramatically lower insulin levels.” Even if you don’t find yourself losing weight right away, your body still benefits from intermittent fasting—you quit relying on short bursts of carbs for fuel, and your insulin sensitivity improves. All you have to do is confine your eating to a set period of time during the day. You can still eat the foods you love, so long as there’s a regular period where you don’t consume any extra calories. You might have to skip your late-night glass of wine and forget about a midnight snack, but the results are worth it.
The best part is that after the initial intermittent fasting induction, studies have shown that patients report feeling fine—that is, not hungry at all during the fasting window—and that this diet is remarkably easy to keep up.
How to safely try intermittent fasting
Healthline suggests that intermittent fasting is safe and effective—all you need to do is limit your caloric intake to an eight-hour window each day. For best results, eat as much healthy food as possible, like lean proteins, fruits, vegetables, whole grains and healthy fats like those found in olive oil, avocados and salmon.
You can also drink coffee, water and tea to help keep those cravings at bay. Caffeine has the added benefit of suppressing the appetite while stimulating the body, so you’ll burn more calories during your workouts and fasting.
For best results, you still need to exercise regularly, but you’re not required to achieve Arnold Schwarzenegger levels of fitness to lose weight. Follow your doctor’s recommendations for healthy activity (usually several hours of dedicated exercise like walking, running and other cardio training per week) to help force your body to burn fat as fuel.
As always, your results may vary, and if you have other health restrictions that make intermittent fasting a no-go, there are plenty of other diets to try. However, if you’re in good health and just want to beat the brain fog, lose some weight and maybe even increase longevity, intermittent fasting is worth a try.