Intermittent fasting (often known as IF) is a popular diet strategy that helps people lose weight by restricting when they eat rather than what they consume. The phrase “intermittent fasting” is rather confusing because “intermittent” technically means at irregular intervals, and “fasting” refers to not eating food for an extended period of time, which most people do every day. The intermittent fasting diet is more accurately described as time restricted feeding, in which a person chooses a set time frame to eat and not eat. The fasting frame is typically 14-20 hours, and the feeding window is 4-10 hours.
A meta-analysis of human and animal research indicated that time-restricted meals reduced body weight, cholesterol, fat concentration, and insulin insensitivity, as well as reducing metabolic disorders (1). In an 8-week scientific investigation, 34 resistance-trained males were separated into two groups: a normal diet group (ND) and a time-restricted eating group (TRD). The TRD group consumed all of their daily calories during an 8-hour window, with meal periods at 1pm, 4pm, and 8pm, whereas the ND group consumed the same number of calories and macronutrients but could eat whenever they wanted. The results showed that the time-restricted group had less fat and more muscle mass, and better biomarkers for metabolic rate and thyroid function. Other than weight loss, many studies have also found that intermittent fasting can have many health benefits, including improvements in chronic ailments, glucose management, inflammation, endurance training, and abdominal fat removal, improvement in blood pressure and heart rate. While what we eat is essential, so is when we eat.
The core concept underlying the physiological benefits of time-restricted feedings is that eating causes mild oxidative stress on your body, whereas fasting helps your body to repair DNA, synthesis protein, activate autophagy, and reduce inflammation. It is proven that blood glucose levels rise when you eat carbohydrates. Your body will generate insulin to either consume or store the energy. When you eat infrequently during the day, your organs are pushed to operate continually, resulting in greater glucose levels, insulin production, and inflammation.
Timed eating has also been shown to provide psychological effects. In a meta-analysis of nearly 500 papers, the total adherence rate to time limited eating was around 80%, which is significantly higher than the usual diet compliance rate of less than 50%. Many people struggle to stay to a calorie-restricted diet due to the difficulties of portion control, underestimating of calories consumed, overestimation of calories burned, and the overall mental strain of constantly making the decision not to eat something. Time restricted eating alleviates most of the mental burden by eliminating food options and replacing them with a clear and straightforward rule to limit when you eat. The same meta-analysis discovered that 20% of time-restricted eating participants unintentionally lowered their calories and experienced a 3% weight loss without deliberately aiming to restrict calories.
Fasting can be done in two ways:
Alternate-day restricted eating and daily time restricted feedings. A 24 hour alternate day fasting program includes at least one day of reduced calorie consumption of 500-700 total calories. The diet of 5:2 diet consists of five regular days and two fasting days, is the most well-studied alternate day protocol. You can continue to consume your typical diet of roughly 2000 to 2500 calories five days a week. On fasting days, however, you can only eat 500-700 calories for the entire day. This should cut your regular 15,000 calorie week to 11,000 calories, resulting in a pound of weight loss per week. The advantage of this diet is that you do not have to restrict the types of foods you eat; instead, you focus on dramatically cutting your calories on two out of the seven days. This type of behavior can aid in the transition from glucose to ketones and fatty acids. This diet, however, has significant disadvantages. A 500-calorie day might leave you fatigued, confused, dizzy, and unable to exercise.
Most people will find the second approach of restricting their meals within a 24 hour period simpler to follow because it is less disruptive and avoids low calorie days. You must choose recurrent time periods to eat and not eat as part of the daily restrictive eating strategy. Because the average person is awake for 16-18 hours and sleeps for 6-8 hours, you should attempt to keep your eating window as small as possible while keeping a regular healthy lifestyle.
How long should I go without eating? This is a very personalized inquiry that will necessitate some trial and error. Some people will follow the “warrior diet,” which consists of fasting for approximately 23 hours and eating one substantial meal within one hour each day. People who eat within a 12-hour window have found positive benefits, which is the least restrictive option. According to studies, the optimal feeding window is usually between 6 and 10 hours, because eating longer than 10 hours in a day provides modest benefits while eating less than 6 hours causes people to overeat (10) (11). According to research, the longer the fast, the bigger the weight and fat loss advantages (12). However, because there are so many factors, there is no silver bullet for determining the best approach. You should think about your fitness goals, whether they are weight loss, muscle building, or sports performance, as well as biological parameters like gender, age, body fat, and muscle mass. Then analyze your behavioral habits, such as work, fitness, and sleep. It is equally critical to consider your mental ability for adherence, performance, and enjoyment. From then, gradually narrow your eating window until you discover your sweet spot.
Making A Time Restricting Feeding Schedule Here are seven simple steps to making a Time Restricting Feeding Schedule.
Tip #1: In the morning, wait at least one hour before eating, and stop eating 2-3 hours before going to bed.
Tip #2: Take your time adjusting to this new diet by reducing your eating window by one hour per day.
Tip #3: To temporarily satisfy your appetite throughout your fasting period, sip a glass of water with lemon and salt. People frequently confuse hunger with dehydration or a lack of salt.
Tip #4: Stick to a regular eating schedule, such as 12pm to 8pm. This eating window is ideal since it allows you to have lunch and supper at regular times, allowing you to enjoy meals with friends, family, or work colleagues.
Tip #5: Maintain your fasting state by eating fewer processed carbohydrates and refined sugars and more high protein and fiber foods.
Tip #6: Try going for a walk, stretching, or taking a supplement like Berberine to reduce your glucose levels after a large meal.