According to some researchers, fasting for 10–16 hours can cause the body to turn its fat stores into energy, which releases ketones into the bloodstream. This should encourage weight loss. This type of intermittent fasting plan may be a good option for beginners.
Consider a simple form of intermittent fasting.
Limit the hours of the day when you eat, and for best effect, make it earlier in the day (between 7 am to 3 pm, or even 10 am to 6 pm, but definitely not in the evening before bed). Avoid snacking or eating at nighttime, all the time.
For example, studies have found that people who regularly fast more than 16 or 18 hours a day have a higher risk of gallstones. They're also more likely to need surgery to remove the gallbladder. Eating for 12 hours and then fasting for 12 hours is likely safe for most people, Longo explains.
The benefits of 12 hour fasting include weight loss, improved digestion, improved sleep, increased mental health and clarity, and reduced insulin resistance.
Eat a normal diet five days a week and fast two days per week. Eat normally but only within an eight-hour window each day. For example, skip breakfast, but eat lunch around 11 a.m. and dinner by 7 p.m.
Alternate-Day Fasting
In fact, research found that, in overweight adults, alternate-day fasting significantly reduced body mass index, weight, fat mass, and total cholesterol.
As part of a 2019 study, researchers followed 19 adults with metabolic syndrome whose meals were spread over a 14-hour window and found limiting meals to a 10-hour window (followed by 14 hours of fasting) was associated with weight loss, smaller waist circumference, lower blood pressure and LDL “bad” cholesterol.
The 4-4-12 method has a shorter fasting window—12 hours—but eliminates snacking between meals. The goal here is to fast for at least four hours between breakfast and lunch, four hours between lunch and dinner, and at least 12 hours between dinner and breakfast the next day.
The rules for this diet are simple. A person needs to decide on and adhere to a 12-hour fasting window every day. According to some researchers, fasting for 10–16 hours can cause the body to turn its fat stores into energy, which releases ketones into the bloodstream. This should encourage weight loss.
A good rule of thumb for those wanting to fast to improve their metabolic and overall health is to leave at least 12 hours between meals – ideally more – on a regular basis, according to Dr Adam Collins, Principal Teaching Fellow in Nutrition at the University of Surrey.
The standard recommendations of fasting would either be a 12:12 fasting, meaning fast for 12 hours and eat for 12 hours. For example, eating is allowed between the hours of 8 am to 6 pm only. However, many people do this fast naturally! We normally recommend the 16:8 fast, meaning fast for 16 hours and eat for 8 hours.
The fountain of youth may be a myth, but you can turn to the next best option: the anti-aging impact of intermittent fasting. Intermittent fasting triggers multiple changes in your body that slow down aging by keeping cells and DNA healthy.
When practicing 14/10 intermittent fasting, you eat every day within a ten-hour window and fast for 14 hours. Not eating for 14 hours may sound challenging, but you have to consider that this includes sleep time. In fact, 14/10 intermittent fasting is not that much different from a normal eating schedule.
The 16:8 is one of the most popular forms of intermittent fasting that can be easily incorporated into daily life. Simply, you restrict eating to an eight hour window with 2–3 meals, and fast for 16 hours.
Does sleeping count as fasting? A. Yes, while following intermittent fasting, sleeping is considered a fasting period. Therefore, one does not consume food or drinks during this state.
If you don't eat for 10–16 hours, your body will go to its fat stores for energy, and fatty acids called ketones will be released into the bloodstream. This has been shown to protect memory and learning functionality, says Mattson, as well as slow disease processes in the brain.
Is 14/10 fasting as good as 16/8? Both fasting methods can lead to health benefits, such as weight loss and improved metabolic health, but 14/10 fasting may not be quite as good as 16/8 in terms of the speed and depth of results you can get.
Myth or Fact: If you cut down on your food intake, you'll eventually shrink your stomach so you won't be as hungry. Answer: Myth. Once you are an adult, your stomach pretty much remains the same size -- unless you have surgery to intentionally make it smaller.
YOU'RE NOT EATING ENOUGH DURING YOUR WINDOW
You'll be so hungry, you may start eating and not stop. As well, the body stores food to protect itself. Your body will sense the need to stock up on reserves and may store those extra pounds as fat instead of lean muscle.
The correct answer is that fat is converted to carbon dioxide and water. You exhale the carbon dioxide and the water mixes into your circulation until it's lost as urine or sweat.
Your muscles first burn through stored glycogen for energy. “After about 30 to 60 minutes of aerobic exercise, your body starts burning mainly fat,” he explains. (If you're exercising moderately, this takes about an hour.) Experts recommend at least 30 minutes of cardio two to three times a week.
When you fast for shorter durations, your body doesn't have enough time to go into ketosis. This means it won't burn stored fat, and there won't be significant weight loss. As one study concluded, a fasting window of 18-19 hours is more effective in terms of weight loss than those between 12-17 hours [11].