Intermittent Fasting Diets
Intermittent fasting diets, which consist of two periods — hunger and satiety — are a practice that focuses not so much on what individuals eat, but on when they eat. Intermittent fasting is carried out by seriously limiting the amount of calories consumed on certain days of the week or at certain hours of the day.
There is no restriction on water and calorie-free drinks on fasting days.
8 TYPES OF DIET
There are various different types of intermittent fasting:
1. Daily Intermittent Fasting: Also known as time-restricted eating, daily intermittent fasting diets consist of an eating period within a certain time window and a fasting period outside that time window. There are different ways to apply daily intermittent fasting diets, but the most popular is the 16:8 rhythm, which involves an 8-hour eating window and a 16-hour fasting period.
2. Weekly Intermittent Fasting: Weekly intermittent fasting diets, preferred more for improving health than for weight loss, involve a 24-hour fasting period on any day of the week, with unrestricted eating continuing on the remaining days. It is generally used as a way to accustom the body before starting intermittent fasting diets.
3. Alternate-Day Intermittent Fasting: In alternate-day fasting practices, there is typically a 24-hour fasting day following a day of normal eating, alternating with 24-hour days of free eating. Fasting days are based on zero calories, and there is no restriction on the consumption of water and calorie-free fluids. If maintaining zero calorie intake on fasting days proves difficult, it is noted that a single meal covering a maximum of 25% of daily energy needs can be consumed around midday (12:00-14:00).
THE BODY IS FED BY ITS FAT STORES
4. Intermittent Fasting and Inflammation: When we eat according to an intermittent fasting pattern, our body is fed by its fat stores. Ketone bodies form as a result of fat burning. These substances prevent the formation of the building blocks of inflammasomes, leading to a reduction in inflammation in the body. While the body is in fasting mode, there is also a decrease in inflammation markers (such as IL-6, CRP and homocysteine).
In a study conducted on humans, three groups were examined that consumed food at intervals of 3-4, 7-8, and 10-12 hours. It was found that the reduction in body weight was significant in the group that ate at 10-12 hour intervals. Positive changes were noted in body weight, total cholesterol, triglycerides, glucose, insulin, IL-6 and TNF-α levels, and insulin sensitivity, and these changes were reported to be greater in the group that fasted for longer periods.
According to another study, fasting for long periods at night has also been shown to be beneficial in reducing systemic inflammation.
5. Intermittent Fasting and Gut Health: Intermittent fasting diets support the gut flora. Since there is no digestion during fasting, the intestines are allowed to rest. It has been suggested that intermittent fasting diets also have a positive effect on the microbiota. Fasting therapy has been found to improve abdominal pain, diarrhea, nausea and anxiety in patients with irritable bowel syndrome.
6. Intermittent Fasting and Insulin Resistance: A decrease in the amount of glucose in the blood during fasting also reduces insulin production. Decreased insulin hormone production helps glucose and fat pass from storage areas into the blood and be broken down. Since blood glucose is low, the energy your body needs is obtained from stored fat and carbohydrate sources.
Decreased insulin levels make your body more sensitive to insulin. Increased insulin sensitivity allows your body to use the food you consume more efficiently.
In a study conducted in the United States in 2012, 30 healthy people aged 18-70 with no metabolic disorders were randomly selected. One group followed an intermittent fasting diet, while the other followed a calorie-restricted diet. The results of this study showed that both insulin and glucose levels decreased in the group that followed the intermittent fasting diet.
7. Intermittent Fasting and Obesity: Today, excess weight and obesity have become a major global health problem due to the predominance of a sedentary lifestyle and easy access to high-calorie foods.
- As the prevalence of obesity increases, an increase is also observed in the prevalence of many diseases, including coronary heart disease and type 2 diabetes.
Diets based on daily calorie restriction are still the most common dietary strategy applied for weight loss. These diets involve reducing energy intake by 20-50% every day. Although these diets are effective for weight loss in some individuals, most people find this type of diet difficult because it requires daily calorie counting. Because people cannot freely consume the amount and type of food they want throughout the day, they can experience more stress with this diet and fail to achieve the desired level of weight loss. In light of these obstacles, another approach called the intermittent fasting diet also offers hope for achieving weight loss goals.
During prolonged fasting, blood sugar drops and less insulin is secreted. The energy the body needs is then supplied from fat stores. This way, weight is lost and fat is burned. Intermittent fasting diets can be used effectively for the treatment of obesity.
8. Intermittent Fasting and Brain Health: Since fats are used by the body during intermittent fasting diets, ketone molecules are formed. Obtaining energy from glucose requires a large amount of oxygen, resulting in more free radicals being formed in the body. When energy is obtained from ketone molecules, on the other hand, less oxygen is used, resulting in fewer free radicals.
Ketone molecules produce energy for cells and also raise the hormone serotonin. Ketone molecules are the reason why people who regularly follow an intermittent fasting diet experience less depression, anxiety disorders, and neurological diseases such as Parkinson's and dementia.
In addition to their effects on the brain, ketone molecules also help improve chronic inflammation resulting from autoimmune diseases (allergies, Hashimoto's, rheumatism, etc.) and the diseases of our era (high blood pressure, diabetes, obesity, etc.).
WHO SHOULD NOT DO THIS?
- Those who are excessively thin
- Pregnant and breastfeeding women
- Children under 16 years of age
- People with anorexia, bulimia or eating disorders
- Substance abusers
There is no single correct approach to nutrition for everyone. Work with a specialist to review your own needs, health conditions and lifestyle, and adopt sustainable, healthy eating habits best suited to your metabolism.
You can find more information on this and related topics in my book “Anti-Inflammatory Nutrition Guide.”