Most animals feed this way when left to their own devices,
allowing for periods of fasting that coincide with sleep.
Intermittent fasting is when you restrict eating to a specific window of time after an overnight fast. Periodically fasting creates an alternate universe with your metabolism, where you depend less on burning sugar and depend more on burning fat (known as ketone bodies).
Why bother? Because intermittent fasting prevents inflammation and decelerates disease, helping you reset key metabolic and stress pathways, remove toxins, lose weight, and, ultimately, age more slowly. This process gives your body more time to rebuild healthy cells. Just like a baby growing from tiny stem cells, we have the ability to heal and regenerate our cells—and intermittent fasting promotes this state.
Note from Dr. Sara Gottfried, MD: While the data on ketogenic diet (high fat, adequate or moderate protein, low carbohydrate) are unclear regarding the benefits to the brain for most healthy individuals, I urge you to try intermittent fasting as a way to enter a fat-burning (ketogenic) state and improving metabolic flexibility. For example, finish dinner by 6 p.m. and eat again at 10 a.m. the next day (a 16/8 protocol, for sixteen hours of a fast followed by an eight-hour feeding window). This turns on longevity genes, and the production of ketones improves focus. Some people need to ramp up to a sixteen-hour fast more slowly—for example, beginning with a twelve-hour, then a fourteen-hour overnight fast twice per week.
By giving the body a break from constant fueling and digestion, we create a window to focus on structural needs and to heal.
Intermittent fasting has been shown to promote health in a variety of ways:
1. In an animal study, it reduces neurodegeneration.
2. In a human study, it has been shown to improve brain function in epilepsy.
3. Intermittent fasting changes circadian clock genes, since eating is associated with light/dark cycles.
4. Multiple studies and reviews describe the beneficial metabolic effects of intermittent fasting.
5. Intermittent fasting in humans for three to twelve weeks reduces body weight by 3% to 7%, lowers body fat by 3 to 5.5 kilograms (6.6 to 12.1 pounds), and lowers total cholesterol by 10 to 21 percent. Intermittent fasting can be one factor in lowering your body weight set point.
6. Reduces inflammation
7. Improves biomarkers of health and counteracts disease.
8. Potentially increases longevity and health span.
We’ve known that intermittent fasting has these benefits, as first documented more than seventy years ago, yet most people aren’t doing it.
With these findings, you need to give intermittent fasting a chance to equalize hormone levels, optimize health, and lose weight quickly!