Some evidence suggests that a 16-hour fasting, 8-hour eating cycle may raise heart disease risk compared with other time-restricted eating cycles. Intermittent fasting also may cause people to feel very tired and dizzy. It can affect diabetes management and cause headaches or mood swings.
Yes, fasting for 16 hours (16:8 method) can help in losing weight by reducing the eating window and promoting a caloric deficit. Additionally, it may improve insulin sensitivity and metabolic health. Pairing intermittent fasting with a healthy, balanced diet is crucial for sustainable weight loss.
If you follow the 16/8 intermittent fasting method correctly, you can expect a weight loss of anywhere between 2 to 6 kgs (approximately 4.4 to 13.2 lbs) in a month. This estimate depends on various factors such as your existing metabolic rate, body structure, body fat, age, physical activity, and stress levels.
If you've tried intermittent fasting but aren't losing weight, possible reasons why include overeating during your eating window and poor food choices. To help, you can try eating fewer calories, work on balancing your meals, or create a smaller or larger eating window.
According to experts, you need at least 10 weeks to see results from intermittent fasting, depending on your metabolism. Fat burning usually begins after 12 hours or more of fasting, peaking between 16 and 24 hours. However, it can take weeks for the human body to transition to intermittent fasting.
While both 12-hour and 16-hour fasting can promote fat burning, it's possible that a 16-hour fast may be more effective. This is because the longer fasting period may lead to a greater depletion of glycogen stores, which can trigger higher levels of fat burning.
Various researchers have reported that fasting may lead to improvements in liver function, potentially indicating a reduction in liver fat accumulation or inflammation. Additionally, total cholesterol levels, which are known to be associated with NAFLD, may also improve during this fasting period.
Fasting for 12 hours a day
According to some researchers, fasting for 12 to 14 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 suitable option for beginners.
For those aiming to lose belly fat, the 16/8 method is often recommended as the best intermittent fasting window to lose belly fat. By fasting for 16 hours and eating within an 8-hour window, you give your body enough time to burn stored fat while still allowing for a manageable eating period.
Intermittent Fasting Foods
You can eat mostly what you want on days when you don't fast. But to lose weight and get the nutrients you need, you should stick to healthy foods and limit treats such as desserts, alcohol, and processed foods. On fasting days, you'll eat very little food or none at all.
Potential Drawbacks of Intermittent Fasting
If you're not already used to skipping meals or not eating for an extended period of time, the hunger and fatigue that can occur when starting IF can be difficult to handle. Other side effects can include insomnia, irritability, headaches, and nausea.
People who follow intermittent fasting either skip their breakfast or dinner, but experts say if the choice is between breakfast or dinner, one should choose to skip the latter.
Natural Fasting Cycle
Every night, when you sleep, your body naturally goes into a fast. Your body's metabolic processes continue, breaking down fats and sugars for energy, even when you're not consuming food.
Water weight is not usually a cause for concern, but it can be uncomfortable and recurring. Reducing salt and carbohydrate intake, keeping hydrated, and frequently exercising are all good ways to lose water weight and prevent it from returning.
After four weeks of consistent fasting, research shows that you should have measurable improvements in blood-glucose levels, insulin levels, insulin sensitivity, and blood pressure to accompany favorable changes in your body weight (assuming you had some excess weight to lose).
If you want to lose 5 pounds in a week, you will need to reduce your food intake by 17,500 calories, which is a huge calorie deficit. If you weigh 250-pound, you will need to reduce your daily calorie intake to about 1,250 calories per day, an amount that is too low amounting to starvation.
Intermittent fasting also allows the GI tract to rest and repair while in a state of fasting. "This is when your body is able to use fat stored in your cells as fuel, so you're burning fat instead of storing it, which leads to weight loss," says Ryskamp.
The most immediate organ affected by a fast is the pancreas. During times of low plasma glucose, the pancreas will release more glucagon from the alpha cells found in the islets of Langerhans. Glucagon will mainly affect the liver as it stores most of the glycogen in the body.
If you're interested in intermittent fasting, Cording suggests trying a 16:8, 14:10, or 12:12 plan. “Look at your schedule and pay attention to when you tend to naturally the hungriest,” she says. “That will give you clues as to what the ideal eating windows would be for you.”
The researchers reported that over three months, people who exercised and followed alternate-day fasting—eating without restriction one day and eating 500 calories or less the next—had increased insulin sensitivity and decreased liver fat, weight and other markers for liver disease.