Getting to the Bottom of the Fasting Trend
What Is Intermittent Fasting?
Intermittent fasting (IF) is a way of eating that involves cycles of fasting. It’s different from other diet plans, as it purely focuses on when, not on what types of food, you eat.
According to research, this method can help manage weight and prevent or reverse some illnesses by prolonging the period in which the body burns calories. Put simply, fasting for a few hours daily, or just eating one meal per day a couple of times each week, may not only burn fat but also benefit your health.
How Does Intermittent Fasting Work?
People who eat throughout the day and never exercise don’t give their bodies a chance to burn their fat stores. In contrast, IF causes the body to switch from using its sugar reserves to burning fat.
You can choose from several different IF schedules, including:
- Time-Restricted Eating – This method involves fasting for 12 hours or longer each day. The 16/8 diet is one of the most popular types of time-restricted eating and is centered around 16 hours of fasting, followed by an 8-hour eating window.
- Alternate-Day Fasting – Also known as ADF, this fasting method involves fasting every other day.
- Eat Stop Eat – Each week, you fast once or twice for an entire day (24 hours).
- The 5:2 Diet – On the 5:2 diet, you eat as you always do for five days. For the other two days of the week, you reduce your calorie intake to 500–600 per day.
- The Warrior Diet – On this diet, you eat some raw fruits and vegetables during the day, followed by a large meal at night.
While only water and zero-calorie beverages like coffee and tea are allowed during non-eating hours, different types of food can be enjoyed during one’s eating window. However, it’s important not to overdo it and binge on high-calorie snacks and junk food. Instead, experts recommend following a healthy eating plan like the Mediterranean diet, which is rich in leafy greens, lean protein, healthy fats, and unrefined carbohydrates like whole grains.
If you are thinking of trying fasting, you should first consult a primary care practitioner.
Intermittent Fasting Benefits
Certain groups, including children under 12, pregnant or breastfeeding women, people with type 1 diabetes who take insulin, and those with a history of eating disorders, should not attempt intermittent fasting.
However, those who can safely participate in IF as a long-term lifestyle change may see a number of health benefits. These include a decreased risk of obesity-related diseases, such as sleep apnea, diabetes, and some types of cancer. Intermittent fasting has specifically been shown to help with:
- Weight loss
- Improved cholesterol levels
- Reduced inflammation
- Improved brain function
According to some studies, intermittent fasting can be more efficient than other diets in reducing inflammation in the body. It can thereby improve certain conditions associated with inflammation like:
- Alzheimer’s disease
- Multiple sclerosis
Keep in mind, though, that the effects of intermittent fasting may vary from person to person, and anyone on the diet should pay attention to any unusual symptoms they may experience. These could include anxiety, headaches, and nausea, among others.
What the Science Says
The potential health benefits of fasting have been supported by animal studies conducted over many years. These studies have shown that fasting may encourage adaptive responses in cells, which enable them to better cope with stress and resist disease.
Since the lack of food during fasting forces the body to rely on its fat stores for energy, it releases fatty acids called ketones, which help protect memory and learning. It’s worth noting that fasting also leads to an overall reduction in calorie intake, which can slow the development of diseases such as cancer.
While significant amounts of research support the health benefits of fasting, most studies have been done on animals, and not on humans. The senior investigator for the National Institute on Aging (which is part of the U.S. National Institutes of Health), Mark Mattson says that there remains “a need for well-controlled human studies across a range of body mass indexes.”
In recent years, intermittent fasting (IF) has become popular as a method for losing weight and enhancing your health. It has been shown to reduce oxidative stress, improve biomarkers of disease, and preserve learning and memory function.
However, it’s important to note that fasting can have different effects on different people and is not for everyone. If you experience unusual symptoms such as anxiety, headaches, or nausea after starting IF, it’s recommended that you consult with your doctor.
Ultimately, intermittent fasting can be a safe and effective way to manage weight and certain health conditions, as long as it is approached with caution and the guidance of a trusted healthcare provider.