Intermittent Fasting for Weight Loss: What Is It and How Does It Work?

Intermittent fasting is an eating pattern in which someone alternates between periods of eating and periods of fasting. For example, someone who is practicing intermittent fasting may only eat during the hours of 8 am to 4 pm, and fast for the remainder of the day. Intermittent fasting does not define what people can eat, just when. 

Studies show that intermittent fasting can stimulate weight loss and can provide significant health benefits to people who are overweight and obese. The benefits from intermittent fasting may also help protect against chronic disease.

How Does Intermittent Fasting Work?

Intermittent fasting aims to help cut down on snacking in between meals, giving the body more time to use up glucose energy sources and therefore move on to burning fat reserves as an energy source.

The Cleveland Clinic describes four types of intermittent fasting:

  • Time-restricted eating: Eating and fasting are done within defined windows of time. For example, eating from 10 am to 6 pm and fasting in between. This can be done once or twice a week, or as often as you’d like.
  • Alternate-day fasting: Fasting every other day. On fasting days, limit calorie intake to 500 calories. On non-fasting days, resume normal healthy eating.
  • The 5:2 diet: For two days of the week, limit calorie intake to 500 calories. For the remainder of the week, resume normal healthy eating. There must be one non-fasting day in between the two fasting days. 
  • The 24-hour fast: A complete fast of zero calories for 24 hours. This can be done once or twice a week. 

Since there are different methods to choose from, pick the method that works best for you, and that you feel you can maintain.

During fasting periods, you are allowed to drink zero-calorie beverages like water, coffee, and tea. While intermittent fasting does not define what people should or should not eat, only when, you may want to take into consideration what you eat and how much you eat during non-fasting hours/days. 

For best results, focus on whole foods such as leafy greens, vegetables, lean proteins, legumes, and complex carbohydrates. Avoid junk food, fast food, and other foods that are high in calories, fat, and sugar. 

What Are the Benefits of Intermittent Fasting?

Studies show that intermittent fasting improves metabolic health, and therefore can result in lower blood sugar levels, lower blood pressure, and lower cholesterol and triglycerides. 

The positive effects that intermittent fasting has on the body can help prevent chronic disease, including:

  • Cardiovascular disease 
  • Diabetes
  • Obesity
  • Declined cognitive performance

How To Get Started with Intermittent Fasting

Before starting an intermittent fasting regimen, we recommend talking to your doctor. Your doctor can help you understand if intermittent fasting may be beneficial for you and can also help you understand which type of intermittent fasting might be best for you.

Some people should not practice intermittent fasting. This includes people who:

  • Have a history of eating disorders, like anorexia and bulimia
  • Have been diagnosed with diabetes
  • Are trying to get pregnant, are currently pregnant, or are breastfeeding
  • Take medication that requires food intake

If you’re finding it difficult to stick to an intermittent fasting plan, don’t give up. Research shows that it takes between two and four weeks for the body to get accustomed to the new intermittent eating schedule.