12 Hour vs. 16 Hour Fast (2024)

FAQs

12 Hour vs. 16 Hour Fast? ›

Both 12-hour fasting and 16-hour fasting can be effective for weight loss, but 16-hour fasting may be more effective because it may lead to a greater reduction in overall caloric intake (through a more condensed eating window) and promote more significant reliance on fat burning.

For weight loss, a 12-hour fast is not as good as a 16-hour fast. But as an effective way to start your fasting journey, a 12-hour fast is likely better!

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.

Fast for 12 hours a 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. This type of intermittent fasting plan may be a good option for beginners.

A 2020 systematic review of 27 studies that involved different kinds of intermittent fasting, including the 16:8 plan, found participants lost between 0.8% to 13.0% of their initial weight with no serious adverse events. The authors concluded intermittent fasting "shows promise" for the treatment of obesity.

Restricting your eating window to a few hours per day can cut your calorie intake over the course of the day, which in turn may contribute to weight loss. In fact, research reveals that fasting may boost weight loss.

Best Intermittent Fasting Method For Visceral Belly Fat

14/10 Method: Fast for 14 hours and have a 10-hour eating window daily. That means you restrict your food intake to a specific 10-hour period while abstaining from caloric consumption for the remaining 14 hours.

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.

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.

Intermittent fasting has been shown to improve insulin sensitivity, reduce blood sugar levels, and lower the risk of developing type 2 diabetes. In addition, after one month of intermittent fasting, you may notice improved metabolic health and reduced risk of chronic diseases.

Do you start burning fat after 12 hours of fasting? ›

Keto is short for ketosis, the metabolic process that kicks in when your body runs out of glucose (its preferred energy source) and starts burning stored fat. Your body may go into ketosis after just 12 hours of not eating, which many people do overnight before they "break fast" with a morning meal.

While fasting, you can burn around 50-100 calories per hour.

Some people skip breakfast and eat from noon to 8 p.m., while others avoid eating late and stick to a 9 a.m. to 5 p.m. schedule. Research indicates that time-restricted eating patterns such as the 16/8 method may prevent hypertension and reduce the amount of food consumed, leading to weight loss ( 5 ).

Researchers found that fasting for 16 hours is beneficial to your body as long as you do not have comorbidities. If planned well, a 16-hour intermittent fasting diet provides you with many long-lasting health benefits. It is one of the easy diets to follow.

A person can eat what they want when following an intermittent fasting plan. However, to reach health and weight management goals, it is a good idea to follow a balanced, high protein, high fiber, vegetable-rich diet during the eating periods.

Julie Upton, MS, RD, and cofounder of Appetite for Health, said that most dietitians recommend a form of intermittent fasting that fits within someone's lifestyle, and a 14-hour fasting window is more doable than a 16-hour fasting window.

Short-term activation: Shorter fasting durations — such as 12 to 16 hours — can stimulate a moderate level of autophagy over a short period of time. This level of autophagy may help with routine cellular maintenance and contribute to overall health.

Depending on your lifestyle and when you can manage to stop eating, the best hours for intermittent fasting include the 16/8 or 14/10 fasting periods. Intermittent fasting is hailed by many as the new mantra of weight loss, disease prevention, and reversal of aging.

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.