Losing Weight with Intermittent Fasting: Does it Work?

Jenna Hilton
January 18, 2023

In the past decade, intermittent fasting (IF) has emerged as an innovative eating regime that primarily focuses on when you eat instead of what you eat.

Intermittent fasting has long been done for religious reasons, but research shows it has positive effects on weight management. By helping to regulate appetite and blood sugar levels, and increase fat burn, intermittent fasting can contribute to your weight loss journey.

This article explains how intermittent fasting supports weight loss, discusses its other health benefits, and provides several IF plans.

Intermittent fasting and weight loss

What Is Intermittent Fasting?

Intermittent fasting is an eating pattern in which periods of unrestricted eating are followed by periods of fasting when we eat no food or only minimal amounts.

In the modern world, we have become used to eating three meals a day, with frequent snacks in between. This means that our bodies never get enough time to use up all the calories we ingest.

With intermittent fasting, the goal is to extend the period between meals. During this time, the body uses up the calories previously ingested and burns fat more effectively.

Note: Intermittent fasting goes hand in hand with other healthy lifestyle choices. For more weight loss tips read our blog article.

How Does Intermittent Fasting Work?

When we go for extended periods without food, we deplete our stores of glucose (sugar), our body’s primary energy source. With no glucose to burn, the body moves on to the secondary source of fuel – fat. This state is called ketosis.

During ketosis, the body starts breaking down fat to produce ketones, which become the body’s main energy source. This fat-burning process begins after around 12 hours of fasting and peaks between 16 and 24 hours.

To stay in a fasting state, it is necessary to refrain from eating solid foods, while beverages such as water, black coffee, and unsweetened tea are allowed. In fact, experts recommend larger amounts of water than usual to avoid dehydration and organ failure.

What to Eat During Intermittent Fasting?

During the eating cycle of intermittent fasting, experts recommend a balanced diet rich in all the essential nutrients. Besides being better for your health, unprocessed, nutrient-dense foods will keep your energy levels up during fasting. Make sure you get enough of the following:

  • Protein – Lean meat, eggs, fish, dairy, legumes, nuts.
  • Fiber – Fresh fruits and vegetables, whole grains such as brown rice.
  • Complex carbohydrates – Legumes, whole grains, fruits, vegetables.
  • Healthy fats – Avocado, nuts, seeds, fish, eggs, olive oil.

Before you begin intermittent fasting, talk to your health provider so they can recommend a regimen and the exact number of calories you need to ingest.

Note: Find out what is the best 7-day meal plan for weight loss that will help you achieve your desired weight.

Does Intermittent Fasting Work for Weight Loss?

Current research shows that intermittent fasting can contribute to weight loss.

The primary weight-loss mechanism behind intermittent fasting is calorie restriction. Put simply, not eating during certain periods of the day means we ingest fewer calories overall. In this sense, intermittent fasting shows similar results to weight-loss diet plans which involve reducing caloric intake.

However, intermittent fasting will not work if during the eating periods we make up for the unconsumed calories by taking the “unrestricted” part literally. You should still be mindful of your meals and portions, as you would with any other weight loss meal plan.

Intermittent Fasting Benefits

Intermittent fasting has many benefits for your overall health, not only in terms of weight loss. Many of these benefits result from the increased production of ketones that occurs during fasting, which has beneficial effects on multiple physical systems.

1. Improves metabolic switching

Metabolic switching is the body’s ability to change energy sources, from glucose stored in the liver to ketones stored in fat. Intermittent fasting improves the speed at which this switch occurs.

Usually, when our glucose stores are depleted, we feel our energy drops and crave food which will increase it. Intermittent fasting trains our body to efficiently switch to burning fat once we’ve used up all our glucose. This means we can go longer without food and don’t experience the sugar crash that can cause binge eating of junk food.

2. Promotes cell reparation and tissue health

Intermittent fasting contributes to cell growth and tissue reparation and maintains organ health. Studies show that IF promotes autophagy – a process that helps the body recycle old, damaged cell components to optimize the functioning of cells.

This process, which produces younger, healthier cells, has been linked to slower aging and increased longevity. Scientists also believe that autophagy can help prevent and manage diseases such as cancer, diabetes, Parkinson’s, etc.

3. Reduces inflammation

Researchers believe that there is a connection between inflammation and the modern diet. Intermittent fasting helps to reduce chronic inflammation by lowering the production of pro-inflammatory cells.

Periods of fasting can prevent inflammation-related diseases, such as heart disease, arthritis, asthma, multiple sclerosis, and others. Some studies also suggest that IF moderately relieves irritable bowel syndrome (IBS).

4. Reduces insulin resistance

Intermittent fasting improves insulin sensitivity. While the body is in the fasting state, insulin levels in the blood drop significantly, lowering the risks for diabetes and pre-diabetes. In addition, improved insulin sensitivity helps relieve the symptoms of polycystic ovary syndrome (PCOS).

5. Promotes brain health

Intermittent fasting has a positive effect on brain health, promoting brain cell growth and preventing the development of a variety of neurological disorders. Clinical studies show that IF benefits patients suffering from epilepsy, Alzheimer’s, and multiple sclerosis. It can also reduce brain damage after a stroke by decreasing free radicals that kill vulnerable cells.

Studies also show that periods of fasting improve memory. People who practice intermittent fasting also report clearer thinking and an improvement in general mental health, with reduced levels of anxiety and depression.

6. Increases physical endurance

Studies show that intermittent fasting promotes endurance during exercise and boosts muscle build if combined with a balanced diet and the right activity. By affecting human growth hormone levels, intermittent fasting is effective at preventing muscle loss that accompanies weight loss over a longer period.

Note: Learn about the positive effect of IV therapy for athletic performance.

7. Improves hormone levels

Aside from the positive effect on your insulin levels, intermittent fasting benefits the levels of norepinephrine (noradrenaline), the hormone that helps convert body fat into energy. By boosting human growth hormone (HGH) levels, intermittent fasting promotes long-lasting weight loss results through increased fat burn.

Potential Side Effects of Intermittent Fasting

Intermittent fasting can be a significant lifestyle change and comes with its own set of challenges. People who start a regime of intermittent fasting may experience these mild to severe side effects:

  • Irritability and mood swings
  • Decreased concentration
  • Headaches
  • Dizziness
  • Fatigue
  • Nausea
  • Constipation
  • Dehydration
  • Nutrient deficiency
  • Difficulty sleeping
  • Hair loss
  • Menstrual cycle changes

People who start intermittent fasting should carefully plan their eating and fasting regimen to accommodate their health and lifestyle needs. It is also essential to eat a balanced and healthy diet during the eating periods so as not to deprive the body of essential nutrients and avoid serious side effects.

Who Should Avoid Intermittent Fasting?

Intermittent fasting is not suitable for everyone, and you should consult your doctor before you begin. Intermittent fasting can be dangerous for certain people:

  • Children under the age of 18.
  • People with a history of eating disorders (or risks of developing eating disorders).
  • People with type 1 diabetes who take insulin.
  • People on medication that requires regular food intake.
  • Underweight people.
  • People with immunodeficiency.
  • People suffering from low blood pressure.
  • People with dementia, brain injury, or in a post-concussion state.
  • People who are pregnant, trying to get pregnant, or breastfeeding.

How to Intermittent Fast?

There are several ways to implement intermittent fasting. Find a plan that suits your lifestyle and needs and remember to consult your doctor. You can always start with a shorter fasting window and increase it as time passes and you get used to more extended periods without food.

Intermittent Fasting Plans

There are six common intermittent fasting plans.

  1. The 12:12 method – This method involves eating during a 12-hour time frame while you fast for the remaining 12 hours. It is suitable for first-time intermittent fasters.
  2. The 16:8 method – This method means following a pattern of an 8-hour eating and 16-hour fasting period. You can choose when the eating cycle begins.
  3. The 5:2 method – This method means eating regularly for 5 days a week and then restricting your calorie intake to a quarter of what you usually eat (typically 500-600 calories per day) for the 2 remaining days.
  4. Eat-stop-eat – This eating plan includes choosing any 2 non-consecutive days to fast for 24 hours while eating normally for the remainder of the week. With this method, you should especially avoid overeating, to avoid counteracting the results of fasting.
  5. Alternate-day fasting – As the name suggests, this includes fasting every other day. If this method is too drastic, you can adapt it by eating 500 calories on fasting days. Studies suggest that the best weight loss results are achieved if you use this method between 3 and 12 weeks.

Keep in mind that long uninterrupted periods of fasting (over 24 hours) may not be beneficial and can lead to health problems.


Intermittent fasting is a breakthrough eating regime that can significantly benefit your weight loss efforts if done properly. It also contributes to your overall health by regulating blood sugar, improving metabolism, and preventing various serious diseases.

Intermittent fasting is not suitable for everyone, so make sure to consult your medical provider and notify them of any underlying conditions you may have before starting this regime for weight loss.

Jenna Hilton
Jenna Hilton has been a practicing PA since 2009, specializing in Family, Internal Medicine and Medical Aesthetics. She attended Arizona State University where she received her Bachelor's Degree and graduated magna cum laude. She received her Master of Science degree in Physician Assistant Studies from A.T. Still University.

Jenna has been injecting neurotoxin and dermal filler since 2013. She received certification as a Master Injector in 2017 through Empire Medical in Los Angeles, California. She is currently working on a Fellowship Program in Anti-Aging and Regenerative Medicine through the American Academy of Anti-Aging Medicine. Her special interests include use of PLLA, Ablative/Non ablative skin resurfacing, PDO threads, hormone therapy and nutritional therapies to improve cellular regeneration and medically supervised weight loss.

Jenna Hilton believes in a multi-factorial approach, considering internal factors that accelerate aging and disease development. She always enjoys teaching. She co-founded Vibrant EDU courses at Vibrant Skin Bar and regularly performs one-on-one training with fellow injectors. She teaches Aesthetic and Advanced Injectable Courses at National Laser Institute. She has been named Preceptor of the Year and is an Adjunct Faculty Member at Midwestern University. She was born in Iowa, and lives with her husband and three children in Phoenix, AZ.

Featured Treatment:

Have a Question?

Vibrant Vitality Clinic - Advanced Hormone Replacement. Sexual Regenerative Medicine and Wellness Therapies.
Let's Connect!

Latest Blog Post:

Become a Member:

Search The Website:

Buy  Treatments online:

Connect with us:

4325 E Indian School Rd, Suite 130
Phoenix, AZ 85018
United States

(480) 422-2058

Monday - Friday: 9:00 am - 6:00 pm
Saturday: 9:00 am - 3:00 pm
Sunday: Closed

Follow us on Social media:

Connect With Us:

4325 E Indian School Rd Ste 130, 
Phoenix, AZ 85018

Find More From Us:

Vibrant Skin BarSHOP - Vibrant Skin Bar

Find Us On Map:

linkedin facebook pinterest youtube rss twitter instagram facebook-blank rss-blank linkedin-blank pinterest youtube twitter instagram