What is intermittent fasting? Fasting has been practiced throughout human history. A long time ago, fasting from time to time was more common than always eating 3 or more meals a day. This is because ancient people didn’t have groceries, supermarkets, or food easily available all year-round. Sometimes, they could not find anything to eat at all. As a result, humans learned to adapt without food for an extended period of time.
Some people practice fasting for religious reasons, but this is only within specific periods. Today, there is a different type of fasting that is becoming popular in the health and fitness community. It is called intermittent fasting. People use it to lose weight and reduce the risk of chronic diseases. In this article, you will learn more about intermittent fasting and weight loss.
What is Intermittent Fasting?
Intermittent fasting (IF) is an eating pattern which cycles between periods of fasting and eating. It does not specify which foods to eat, but rather when to eat them. Fasting usually entails abstinence of food during a certain period of time.
You can say that intermittent fasting is not really a diet, but can be more accurately described as a pattern of eating. The aim of IF is to change body composition through loss of fat and to improve health markers such as blood pressure and cholesterol levels.
For a certain period, intermittent fasting requires complete abstinence, or a reduced amount of food and beverages. You can drink liquids during the fast. Water, tea, coffee, and non-caloric beverages are fine. However, don’t add sugar to your coffee.
Intermittent Fasting Methods
There are different methods of intermittent fasting. All of them involve splitting the day/week into eating and fasting periods. During the fasting period, you eat very little or nothing at all. These are the most popular intermittent fasting methods:
• 16/8 Method – Also known as the Leangains protocol, this involves skipping breakfast. You will then restrict your daily eating period to 8 hours (for example, 11 am to 7 pm). Essentially, you’ll be fasting for 16 hours.
• 5:2 Diet – With this method, you consume only 20 to 25% of your regular calories for 2 days of the week. You can eat normally the other 5 days.
• Alternate Day Fasting – Fast on one day, eat normally the next. Eat only 500 to 600 calories on your fast day, but you can eat normally on your off day. As the name suggests, you have to alternate days of normal eating and fasting.
By reducing your calorie intake, these methods can help you lose weight. Most people find the 16/8 method to be the simplest and easiest to stick to. It is also the most popular.
Health Benefits of Intermittent Fasting
The benefits of intermittent fasting include:
• Fat loss – Natural sugars in food that are not immediately used for energy are stored as glycogen in the liver. Even though stored glycogen is the first fuel source your body uses, when those are gone (after 6 to 8 hours), your body turns to fat cells for energy. Eating throughout the day makes it more difficult for the body to burn fat because it doesn’t run out of stored glycogen. Intermittent fasting makes it possible to tap into fat stores.
• Heightened alertness – Some people say they became more alert with intermittent fasting. It is possible that the body goes into ketosis during fasting. Ketosis provides fuel for the body and brain. In the absence of glucose, the body produces ketone bodies to feed the brain. The ketones may be the reason why people say they are more alert and focused. However, more research is needed to prove this.
• An improved relationship with food – People may have different experiences when it comes to intermittent fasting and weight loss. But in general, those who tried IF noticed positive changes not only in body weight, but in their overall health as well. Intermittent fasting will change your perception of food and nutrition. Basically, you’ll be gaining control of what and how you eat. It builds self-discipline, too.
Other health benefits of intermittent fasting include:
• Weight loss – Intermittent fasting can help people lose weight and belly fat.
• Insulin resistance – IF can reduce insulin resistance, lowering blood sugar by 3 to 6% and fasting insulin levels by 20 to 31%, which can protect you against type 2 diabetes.
• Inflammation – Some studies show that IF can reduce markers of inflammation, which cause many chronic diseases.
• Heart health – IF may reduce bad cholesterol (LDL), blood sugar, blood triglycerides, and insulin resistance, which are all risk factors for heart disease.
• Anti-aging – Animal studies show that fasted rats lived 36 to 83% longer.
Disadvantages of Intermittent Fasting
This type of eating pattern would be difficult for somebody who normally eats every few hours (for example, snacks between main meals). It is also not appropriate for people with conditions that require taking food at regular intervals due to metabolic issues and medications, such as those with diabetes.
Furthermore, prolonged periods of semi-starvation and food deprivation also places one at risk of overeating when food is reintroduced. It may also foster unhealthy behaviors such as a heightened fixation on food. Because IF focuses more on timing and not on what specific foods to eat, some people may make impulsive choices like eating chips or cookies when it’s time to eat. These foods are high in calories, but low in nutritional value.
Another disadvantage of intermittent fasting is that it doesn’t involve exercise in losing weight. Moreover, with IF, there’s a possibility that the body may be burning not only fat, but also muscle. This may impact muscle strength and body shape.
People with the following conditions should avoid intermittent fasting:
• Eating disorders such as anorexia or bulimia nervosa
• Pregnancy, breastfeeding
• Active growth stage (adolescence)
• Use of medications that require regular food intake
What Does Research Say about Intermittent Fasting?
In animals, calorie restriction has been shown to increase lifespan and improve tolerance to metabolic stress. Although the evidence in animal studies is strong, human studies need more solid evidence to prove the benefits of intermittent fasting.
One study conducted in 2014 found that intermittent fasting can cause 3 to 8% weight loss over 3 to 24 weeks. Proponents believe that IF causes an immune response that produces positive metabolic changes (reduction in weight, fat mass, blood glucose, blood pressure, triglycerides, and LDL cholesterol). However, one concern regarding intermittent fasting is that followers may overeat on non-fasting days.
A review of 40 studies showed that IF was effective for weight loss, with a loss of 7 to 11 pounds over a period of 10 weeks. It is important to note that the studies ranged in size (from 4 to 334 subjects) and duration (from 2 to 104 weeks). Different intermittent fasting methods and study designs were used, and participant characteristics also differed (lean vs. obese).
Half of the studies were controlled trials, comparing the intermittent fasting group to a comparison and/or control group (either usual lifestyle or continuous calorie restriction), while the other half only examined an intermittent fasting group.
Intermittent fasting is one of the most popular health and fitness trends today. People are using it to lose weight and improve their health. Some studies in animals show that it can have beneficial effects and may even help increase lifespan. However, more conclusive evidence is needed to prove the health benefits of intermittent fasting in humans. If you have questions about intermittent fasting and weight loss, consult your doctor.
Want to learn more about weight loss and healthy nutrition? Sign up to FITin56 now!