Luke Stanaway

Registered Nutritionist

Intermittent Fasting: How Quickly Can You Lose Weight?

Intermittent Fasting: How Quickly Can You Lose Weight?

Intermittent Fasting: How Quickly Can You Lose Weight?

Key Takeways

  • Intermittent fasting can lead to weight loss, with an average of 3-5kg lost over 10 weeks, equating to 0.4kg lost per week.

  • Reduced calorie intake is the main mechanism behind weight loss with intermittent fasting.

  • There are several different methods of intermittent fasting, including the 16:8 method, the 5:2 diet, the Warrior diet, Eat Stop Eat, and alternate-day fasting.

  • For successful weight loss through intermittent fasting, it is important to focus on the quality of food, monitor caloric intake, and be consistent with the chosen method.

  • Further research is needed to fully understand the benefits and long-term implications of this diet.

The rate of weight-loss using intermittent fasting

A systematic review of 40 studies found that intermittent fasting can effectively lead to weight loss, with an average of 3-5kg lost over 10 weeks, equating to 0.4kg lost per week. Participants in some of these studies also experienced a 4-7% reduction in waist circumference, indicating a loss of belly fat.

How does Intermittent Fasting cause weightless?

Reduced calorie intake is the primary mechanism underlying weight loss with intermittent fasting. Fasting periods in various protocols involve skipping meals, which results in fewer calories consumed unless overcompensated during eating periods.

Which type of intermittent fasting should I use?

There are a variety of different methods of intermittent fasting, the most popular include:

  • the 16:8 method

  • the 5:2 diet

  • the Warrior diet

  • Eat Stop Eat

  • alternate-day fasting (ADF)

All of these methods can yield results, but the best method for a particular person is determined by their lifestyle. Here’s a blog that explores the differences between them in-depth.

The best way to tackle an intermittent fasting protocol

Here are a few things to keep in mind for successful weight loss through intermittent fasting:

  1. The quality of food is important. Consume whole, single-ingredient foods.

  2. Keep an eye on your caloric intake.

  3. During non-fasting periods, aim to eat normally without compensating for calories lost while fasting.

  4. Be consistent. Sticking to a routine is important for achieving results with any weight loss method.

  5. Patience. It may take some time for your body to adjust to an intermittent fasting protocol, so be patient and stick to your meal plan.

Most of the popular intermittent fasting protocols also recommend exercise, such as strength training. This is very important if you want to burn mostly body fat while maintaining your muscle mass. In the beginning, calorie counting is generally not required with intermittent fasting. However, if your weight loss plateaus, calorie counting can be a useful tool.

Who should avoid intermittent fasting? 

Intermittent fasting might not be right for everyone. This diet should be avoided by the following groups of people:

  • Children and young adults under 18 years old

  • Pregnant or breastfeeding women

  • Individuals with diabetes or blood sugar issues

  • People with a history of eating disorders

  • Individuals taking medication that requires them to eat first

More research is required to fully comprehend the potential impact of intermittent fasting on mental health. Concerns include an excessive focus on food and the transmission of bad eating habits to children.

While effective, it is critical to view intermittent fasting as a tool rather than allowing it to control your life. Remember that weight loss journeys are often difficult, so be gentle with yourself during the process.

Common unanswered questions

  • What is the best fasting frequency and duration to achieve therapeutic results?

  • Is intermittent fasting safe and beneficial for a variety of populations, including healthy people, people with chronic diseases, and the elderly?

  • What are the long-term implications of this diet?

  • Can Intermittent Fasting have a negative impact on the eating habits of others, especially children who see their parents avoiding food and skipping meals?


While animal studies have shown that caloric restriction has benefits, the same cannot be said for humans, and the benefits of intermittent fasting are still largely unknown. In comparison to other weight loss methods, the efficacy of intermittent fasting is still emerging, including its impact on weight loss, biological changes, adherence, and appetite. Intermittent fasting may be more manageable for those who eat only one or two meals per day or go long periods without eating. Additionally, those who eat or snack excessively at night may benefit from reducing their eating time, especially if it causes unwanted side effects such as acid reflux or disrupted sleep.

More research, including well-designed trials with a one-year follow-up period, is needed to determine the direct effects and potential benefits of intermittent fasting. At this time, strong recommendations on the use of intermittent fasting for weight loss are not possible.


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