Intermittent fasting is a type of eating plan in which you fast and eat on a regular basis. Studies have demonstrated that intermittent fasting can help people lose weight and avoid — or even reverse — disease. How do you go about achieving it, though? Is it safe as well?
What is intermittent fasting, and how does it work?
While many diets focus on what to eat, intermittent fasting focuses on when to eat.
When you fast intermittently, you only eat at particular periods of the day. Fasting for a set number of hours each day or eating only one meal a few of times a week can aid fat loss. Scientific evidence also suggests that there are certain health benefits.
For the past 25 years, Mark Mattson, a neuroscientist at Johns Hopkins University, has studied intermittent fasting. He says that our bodies have evolved to be able to go for hours, days, or even weeks without nourishment. Before humans learned to farm, they were hunters and gatherers who developed to survive — and thrive — without eating for lengthy periods of time. They had to: Hunting wildlife and gathering nuts and berries took a lot of time and effort.
Even 50 years ago, maintaining a healthy weight was simple. "There were no computers, and TV shows ended at 11 p.m.; people stopped eating because they went to bed," explains Christie Williams, M.S., R.D.N., a Johns Hopkins nutritionist. The portions were significantly smaller. "More people worked and played outside, getting more exercise in general."
Television, the internet, and other types of entertainment are now available every day of the week, 24 hours a day. We stay up later to watch our favorite shows, play games, and communicate on the internet. We spend the entire day — and most of the night — sitting and munching."
Obesity, type 2 diabetes, heart disease, and other ailments can all be exacerbated by eating too many calories and exercising too little. In scientific studies, intermittent fasting has been proven to aid in the reversal of these behaviors.
What is the mechanism of intermittent fasting?
Intermittent fasting can be accomplished in a variety of ways, but they all revolve around establishing regular eating and fasting schedules. You may, for example, try eating only for eight hours a day and fasting the rest of the time. and fasting for the rest of the day. Alternatively, you could choose to eat only one meal each day two days per week. There are a variety of intermittent fasting schedules to choose from.
According to Mattson, the body's sugar stores are depleted after a length of time without eating, and it begins to burn fat. He refers to this as "metabolic flipping."
"Because most Americans eat continuously during their waking hours," Mattson argues, "intermittent fasting is in stark contrast to their typical eating regimen." "If someone consumes three meals plus snacks every day, and doesn't exercise, they're running on those calories and not burning their fat stores every time they eat."
Intermittent fasting works by lengthening the period between when your body burns the calories from your previous meal and when it begins to burn fat.
Plans for Intermittent Fasting
Before beginning intermittent fasting, make sure you see your doctor. Once you get his or her permission, the real process is simple. You can opt for a daily plan that restricts daily meals to a six- to eight-hour window. Try the 16/8 fasting method, which entails eating for eight hours and fasting for sixteen. Williams is a believer in the daily routine, noting that most people find it easy to stick to it over time.
Another method, known as the 5:2 technique, is eating five times a week. You only eat one 500–600 calorie meal on the remaining two days. For instance, suppose you decided to eat normally every day of the week except Mondays and Thursdays, which are your one-meal days.
Fasting for longer periods of time, such as 24 hours, 36 hours, 48 hours, or 72 hours, is not always healthy and can be hazardous. If you go too long without eating, your body may respond by storing fat as a way of compensating for the lack of food.
According to Mattson's research, the body adjusts to intermittent fasting in two to four weeks. While you're getting adjusted to the new regimen, you can feel hungry or irritable. However, he notes that research subjects who make it through the adjustment stage are more likely to continue to the diet because they feel better.
What may I eat if I'm fasting intermittently?
When you aren't eating, you can drink water or zero-calorie drinks like black coffee or tea.And "eating normally" during your periods does not imply going insane. If you fill your meals with high-calorie junk food, super-sized fried foods, and desserts, you're not going to lose weight or get healthier.
Williams, on the other hand, prefers intermittent fasting because it allows him to eat — and enjoy — a wide variety of foods. She explains, "We want people to be conscious and enjoy eating good, nutritious cuisine." Eating with others and sharing the mealtime experience, she continues, enhances satisfaction and promotes excellent health.
Whether you're trying intermittent fasting or not, Williams, like other nutrition experts, considers the Mediterranean diet to be a solid model for what to eat. You can't go wrong when you eat complex, unprocessed carbohydrates like whole grains, leafy greens, healthy fats, and lean protein.
Benefits of Intermittent Fasting
Intermittent fasting does more than burn fat, according to research. "Changes in this metabolic switch affect the body and the brain," Mattson explains.
Mattson's research was published in the New England Journal of Medicine, and it offered information on a variety of health benefits linked to the practice. Among them include a longer life, a thinner body, and a sharper mind.
"Many things happen during intermittent fasting to protect organs from chronic diseases including type 2 diabetes, heart disease, age-related neurological disorders, even inflammatory bowel disease and many cancers," he continues.
Here are some of the research-backed benefits of intermittent fasting:
- The ability to think and remember. Intermittent fasting improves working memory in animals and verbal memory in adults, according to research.
- Heart health is important. Short-term fasting improved blood pressure, resting heart rates, and other heart-related metrics.
- Physical exertion. Fasting for 16 hours resulted in fat loss while retaining muscular mass in young males. Mice that were fed on different days had superior running endurance.
- Obesity and diabetes. Intermittent fasting has been shown to prevent obesity in animals. In six small studies, obese adult individuals lost weight by fasting intermittently.
- Tissue health is important. Intermittent fasting in mice minimized tissue damage during surgery and improved outcomes.
Is intermittent fasting a healthy way to eat?
Some people use intermittent fasting to lose weight, while others use it to treat chronic illnesses including irritable bowel syndrome, high cholesterol, or arthritis. Intermittent fasting, on the other hand, isn't for everyone.
Before attempting intermittent fasting (or any diet), Williams recommends consulting with your primary care physician. Intermittent fasting should be avoided by some people:
- Minors are children and teens under the age of eighteen.
- Women who are expecting or breastfeeding a kid.
- Those who suffer from diabetes or other blood sugar problems.
- Those who have previously struggled with an eating disorder.
According to Williams, people who aren't in these groups but can safely engage in intermittent fasting can continue the practice indefinitely. "It could be a beneficial lifestyle change," she explains.
Keep in mind that depending on the person, intermittent fasting can have a range of effects. Consult your doctor if you have unusual anxiety, headaches, nausea, or other symptoms after starting intermittent fasting.