Studies show that calorie restriction is one of the most reliable ways to lose weight and keep it off, and that’s true whether you cut portions daily or fast weekly.

Fasting also primes your metabolism to burn fat for fuel, which gives you energy and focus without the daily carb cravings.

Last but not least, fasting improves insulin sensitivity – this helps you lose weight in several ways

Though fasting does have potential dangers, these risks are mostly limited to people who are sick, undernourished, and who have eating disorders. (Remember, we all practice some level of fasting every time we sleep or go without food!) Read on to find out what risks are possible when fasting:

• Prolonged fasts of three days and up have been linked to refeeding syndrome — a dangerous electrolyte/fluid imbalance. But this most often occurs in people who are severely malnourished.
• Pregnant women aren’t advised to practice fasting because of potential pregnancy complications.
• Dehydration can occur while fasting. People who fast need to consume more water than usual, because food alone can account for 20-30% of total fluid intake.
• Headaches are a very slight but common issue at first.
• Eating disorders can be magnified in those with anorexia or bulimia.
• Electrolyte imbalances can happen if you go too long without enough minerals – which could lead to dizziness, heart palpitations, and feeling weak. (Doctors recommend taking a multi-mineral tablet and/or adding salt to water during longer fasts.)
• Hunger is a standard risk for all fasters. But it doesn’t last! Studies actually report less overall hunger when participants adhere to an IF practice.

You should always consult your doctor before making major dietary or lifestyle change. But you can (and should!) practice intermittent fasting for as long as you feel good doing so. Doctors are approaching IF not as a short term dietary intervention, but as a long-term way of life

But even during shorter fasts or intermittent fasts, your body is being conditioned to use fat for fuel (ketones) when you don’t have access to carbs and other sources of energy – especially when you exercise.

Whether you try intermittent fasting, 24-hour fasts, or prolonged fasts, the science is overwhelmingly in favor of most fasting practices. Research indicates that fasting improves:

• arterial health
• cognitive health
• digestive health
• longevity
• DNA
• body composition
• sleep quality and duration
• and numerous other aspects of health.

Many of the benefits of fasting come from the cellular clean-up process known as autophagy. Science shows that this process reduces inflammation, increases immunity, and is even important for fighting cancer.

David Perlmutter, author of ‘Brain Maker’: “Fasting is baked into our evolution and our physiology and it can yield benefits to our brains and bodies, at a biochemical level, that we’re only just beginning to understand.”

Dr. Peter Osborne, author of ‘No Grain, No Pain’: “It’s of the cheapest and easiest health tools you can access. Fasting has been shown to be beneficial for a variety of different diseases and health problems including rheumatic diseases, chronic pain syndromes, hypertension, and metabolic syndrome, obesity, cancer, digestive disorders, and more.

Dr. Rhonda Patrick, Ph.D. health researcher: “Most people who practice fasting report feeling energized and more alert at the end of their fast, which may represent a “resetting” of their body’s natural metabolic rhythms.”