What is Intermittent Fasting, is it safe, and how does it work?

Intermittent fasting is a dietary pattern that alternates between periods of fasting and non-fasting. Studies have demonstrated that intermittent fasting can be an effective tool for maintaining a healthy weight and even treating or reversing certain health conditions. But what exactly does it entail and is it safe to practice?
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What is Intermittent Fasting?
While many diets concentrate on what to eat, intermittent fasting focuses on the timing of meals.
The concept of intermittent fasting involves restricting food consumption to specific periods. Scientific research has shown that limiting food intake to a set number of hours each day or eating just one meal a few days a week may have health benefits.
Dr. Mark Mattson, a neuroscientist from Johns Hopkins, has been studying the effects of intermittent fasting for 25 years. He explains that our bodies have evolved to be able to go without food for prolonged periods, including several hours or even days. This adaptation dates back to our ancestors who were hunters and gatherers, who had to rely on their ability to survive without food while they hunted and gathered resources.
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Experts observe that maintaining a healthy weight was easier in the United States just a few decades ago. Back then, there were no computers and televisions would shut off at 11 pm, prompting people to stop eating and go to bed. Additionally, portion sizes were smaller and people were more active, both in work and leisure, which led to a more physically active lifestyle.
However, with the advent of technology, such as the internet, television, and other forms of entertainment, many individuals, both adults and children, spend extended hours indulging in activities like watching TV, browsing social media, playing games, and online chatting.
This often results in a sedentary lifestyle with constant snacking, leading to an increased risk of obesity, type 2 diabetes, heart disease, and other health conditions.
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But there is good news! Research has revealed that intermittent fasting may help reverse these negative health outcomes.
Intermittent Fasting: How Does It Work?
Intermittent fasting involves a pattern of alternating between periods of eating and fasting. There are several approaches to intermittent fasting, each based on choosing specific times for eating and fasting.
For example, one approach could be to limit eating to an eight-hour window each day, fasting for the remaining hours. Another option could be to eat only one meal per day for two days in a week. There are many different intermittent fasting plans to choose from.
According to Mattson, after a prolonged period without food, the body begins to use up its glucose stores and shift to burning fat. He calls this process metabolic switching.
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“Intermittent fasting is a departure from the typical eating pattern of most Americans, who tend to consume food throughout the day,” Mattson says. “If someone is eating three meals and snacks throughout the day without exercising, they are relying solely on those calories and not tapping into their stored fat.
Intermittent Fasting: Dietary Restrictions
During the fasting periods, it is permitted to consume water and zero-calorie beverages such as black coffee and tea.
However, during the eating periods, it is important to maintain a balanced diet. Consuming high-calorie junk food, large fried items, and sugary treats will not lead to weight loss or improved health.
Read also: 11 Healthiest Foods On Earth
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One of the benefits of intermittent fasting, according to some experts, is the flexibility it provides in terms of food choices. Eating a variety of nutritious foods with others and savoring mealtime can add to the overall satisfaction and support good health.
Nutrition experts often recommend following the Mediterranean diet as a guide for healthy eating, regardless of whether you practice intermittent fasting or not. This diet focuses on consuming leafy greens, healthy fats, lean protein, and complex carbohydrates such as whole grains.
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Williams appreciates the flexibility that intermittent fasting offers in terms of food choices. She emphasizes the importance of being mindful and enjoying nutritious food. “Eating good, nutritious food with others and savoring mealtime adds to overall satisfaction and supports good health,” she says.
Like many nutrition experts, Williams considers the Mediterranean diet to be a good guide for healthy eating, whether one practices intermittent fasting or not. This diet emphasizes consuming complex carbohydrates such as whole grains, leafy greens, healthy fats, and lean protein.
Is Intermittent Fasting Safe?
Some individuals adopt intermittent fasting for weight management, while others use it to manage chronic conditions such as irritable bowel syndrome, high cholesterol, or arthritis. However, it is important to note that intermittent fasting may not be suitable for everyone.
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Williams highlights the importance of consulting with a primary care practitioner before making any changes to one’s diet, including trying intermittent fasting. There are certain groups of people who should avoid it, including:
- Children under the age of 12
- Women who are pregnant or lactating
- Individuals with type 1 diabetes who take insulin. Although several clinical trials have indicated that intermittent fasting is safe for people with type 2 diabetes, there is currently a lack of research on its effects in people with type 1 diabetes. According to Mattson, “As people with type 1 diabetes rely on insulin, there is a concern that the fasting period during intermittent fasting may result in dangerously low levels of blood sugar.“
- Individuals with a history of eating disorders.
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However, according to Williams, individuals who are not in the aforementioned categories and are able to safely engage in intermittent fasting can maintain the practice indefinitely. “It can become a lifestyle change that comes with benefits,” she notes.
It is important to note that the effects of intermittent fasting may vary between individuals. If you experience any unusual symptoms such as anxiety, headaches, or nausea after starting intermittent fasting, it is recommended that you consult with your doctor.
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