Intermittent fasting is a diet trend that involves voluntarily abstaining from food or beverages other than water for a certain amount of time, with the goal of weight loss. There are three popular approaches to intermittent fasting:

• Alternate-day fasting: Eat a normal, healthy diet one day and then completely fast or have one small meal the next day. Usually, the small meal is fewer than 500 calories.
• 5-2 fasting: Eat a normal diet five days a week and fast two days per week.
• Daily time-restricted fasting: 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.

Intermittent fasting works by prolonging the period when your body has burned through the calories consumed during your last meal and begins burning fat. It appears that fasting for a short time can produce ketosis, which is a process that occurs when the body doesnt have enough glucose for energy, so it breaks down stored fat instead. This causes an increase in substances called ketones. This, coupled with fewer calories consumed overall, can lead to weight loss.

A systematic review of 40 studies found that intermittent fasting was effective for weight loss, with a typical loss of 7-11 pounds over 10 weeks. However, research does not consistently show that intermittent fasting is superior to continuous low-calorie diets for weight loss efficiency.

Positive aspects of intermittent fasting for weight loss include:

• Convenience: It can cut down on the time and money you need to spend on cooking and preparing food each week.
• Increased weight loss: 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.
• Health benefits: Intermittent fasting has been associated with a long list of health benefits, including improved cardiometabolic health.

Negative aspects of intermittent fasting for weight loss include:

• Overeating: There is a concern that followers will overeat on non-fasting days to compensate for calories lost during fasting.
• Loss of lean muscle mass: Weight loss from any intervention (including intermittent fasting) often entails a concurrent loss of lean muscle mass.

Ingredients or materials are not relevant to intermittent fasting as it is a dietary pattern rather than a product.