why am i not losing weight on intermittent fasting

Why Am I Not Losing Weight on Intermittent Fasting?

Why am I not losing weight on intermittent fasting is a common question I get as a Registered Dietitian specialized in weight loss. 

Intermittent fasting (IF) has surged in popularity as a weight loss strategy in recent years. This method involves cycling between periods of eating and a fasting period. 

Intermittent Fasting promises benefits that come about from calorie restriction and a reduction in body weight. What I love about Intermittent Fasting is that unlike many diets, intermittent fasting doesn’t restrict the types of foods you eat; it focuses solely on when you eat them.

However, not everyone experiences the weight loss they expect from intermittent fasting. Common reasons for this include overeating during eating windows, making poor food choices, or not finding the right balance in meal timing.

To address these challenges, you might need to adjust your caloric intake, ensure balanced meals, or modify the length of your eating and fasting windows.

In this guide, we’ll explore why you might not be losing weight with intermittent fasting, how to overcome these obstacles, and what kind of results you can realistically expect. While intermittent fasting can be an effective tool for a weight loss plan, it’s important to recognize that it’s not a one-size-fits-all solution.

To maximize your results and ensure a sustainable approach, consulting with a registered dietitian can provide personalized guidance. Continue reading to discover how to fine-tune your intermittent fasting regimen for optimal weight loss.

why am i not losing weight on intermittent fasting

What is Intermittent Fasting?

Intermittent fasting (IF) is an eating pattern that cycles between periods of fasting and eating. The main reason intermittent fasting works for weight loss is that it helps reduce overall caloric intake by limiting the amount of time you can eat, known as the eating window. 

This eating plan can take different approaches, such as alternate-day fasting or time-restricted feeding, which allows eating only during specific hours of the day. However, as a dietitian I do need to warn you that some approaches are not only unrealistic, but can also harm your health in the long run.

intermittent fasting not working

Intermittent Fasting Benefits

One of the key health benefits of intermittent fasting is its potential to improve insulin resistance by improving insulin sensitivity thus lowering  insulin levels. This can help with fat loss and reducing the risk of type 2 diabetes. 

By creating a calorie deficit, intermittent fasting can lead to weight loss results. However, it’s important to consume enough protein, fiber and healthy fats to maintain muscle mass and overall health.

Research shows that the intermittent fasting periods do more than just contribute to fat burning. There is a metabolic switch that occurs with intermittent fasting during the fasted state affects the body and brain positively.  This can lead to a longer life, a healthier body and a sharper mind.

Also IF protects organs against chronic diseases like type 2 diabetes, heart disease, age-related neurodegenerative disorders, even inflammatory bowel disease and many cancers. It can also help reduce belly fat which is very important in improving heart health and even mental health. 

However, it’s crucial to maintain a balanced diet and avoid eating too few calories, which can negatively impact metabolic rate and energy levels. Physical activity, getting enough hours of sleep, and a healthy diet rich in whole foods are also vital components of a successful intermittent fasting regimen.

Scientific evidence from research studies and early studies published in journals like the Journal of the American Heart Association supports the effectiveness of intermittent fasting. However, individual results may vary, and it’s essential to approach this  with a long-term perspective for sustainable weight management and overall health. 

Is Intermittent Fasting a Good Weight Loss Strategy

Intermittent fasting (IF) can be an effective weight loss strategy for many people, but it’s important to understand the factors that contribute to its success. The most important thing is creating a calorie deficit by reducing food intake during specific hours of the day, known as the fasting window.

By limiting the time period for eating, intermittent fasting can help control portion sizes and reduce overall caloric intake.

However, it is crucial to point out that this is not a low-calorie diet. Even though it does create a caloric restriction by limiting the times during the day you are eating, that does not mean you are relying on a very low calorie diet for weight loss.

In order for intermittent fasting to be a good weight loss strategy, you must look at in terms of a long term strategy and something you can do for a long time and not something you do as a quick diet trend. This is because when you rely on a quick fix, you do not create the lifestyle nor do you change the habits needed to sustain that weight loss and keep the extra pounds off. 

One of the most important factors to having IF work for you is by eating enough protein, fiber and healthy fats to help you maintain your weight loss while on your weight loss journey.

Check out these blogs for more information: Build Your Meals For Sustainable Weight Loss and The Best Macros for Weight Loss Female: Healthy Fat Loss.

So Why Am I Not Losing Weight on Intermittent Fasting?

intermittent fasting not losing weight

If you’re not losing weight on intermittent fasting, possible reasons could be at play.

Here are some common reasons why you might not be seeing the desired results:

You’re Not Eating Enough Protein

Protein performs a variety of functions in the body and can help in your weight-loss efforts. Research has shown that muscle is more metabolically active than fat, meaning that it burns more calories at rest. So, by eating enough protein, you are able to maintain or increase muscle mass, which can lead to more calories burned per day.

Protein also helps keep you fuller for longer. One study in the American Journal of Clinical Nutrition showed that increasing protein intake to 30% of calories not only increased satiety, but also decreased calories, which resulted in weight loss and fat loss. Exact requirements of protein will depend on your body size, body composition, and how much you exercise. A good starting point is to aim for at least one to two servings of protein at each meal during your eating window.

Overeating During the Eating Window

Consuming too many calories during your eating periods can offset the calorie deficit needed for weight loss. Pay attention to portion sizes and ensure you’re not overindulging. It may be tempting to overeat during your eating window, but if you find that you are overly hungry during your eating window, it may be a good idea to reduce the eating window.

Poor Food Choices

Opting for high-calorie, low-nutrient foods like fast food, ice cream, and sugary snacks can hinder weight loss. Focus on whole foods, lean protein, healthy fats, and whole grains to support your goals. Even though those foods are totally okay in moderation and will not make or break your goals if you are consuming in moderation, these kinds of foods should only be making up about 20% of your meals at most.

Inadequate Caloric Deficit 

Even if you’re eating healthy foods, you might not be creating a sufficient calorie deficit. If you feel that you are eating pretty healthy meals and have no idea why you are not losing weight, then it may be a good idea to track your calorie intake for a few weeks. This helps ensure you eat fewer calories than your body burns.

Irregular Eating Schedule

Consistency is key in intermittent fasting. Sticking to a regular eating schedule helps regulate your body’s metabolic processes. Inconsistent fasting and eating windows can disrupt your progress.

Insufficient Physical Activity

Exercise plays a significant role in weight loss. Incorporate regular physical activity to boost your metabolic rate and enhance fat loss. This can be as simple as taking a 15 minute walk every day.

Not Enough Sleep

Poor sleep or sleep deprivation can negatively impact weight loss. Aim for enough sleep to support your body’s recovery and metabolic functions as well as hormone health!

High Stress Levels

Stress can lead to hormonal changes that promote weight gain. Practice stress management techniques like mindfulness, meditation, or yoga to support your weight loss efforts.


Not drinking enough water can affect your metabolism and make you feel hungrier. Ensure you’re staying well-hydrated throughout the day.

Inadequate Nutrient Intake

Make sure you’re getting enough protein, healthy fats, and other essential nutrients to support muscle mass and overall health. This helps in maintaining a higher metabolic rate.

Adaptation Period

Sometimes, your body needs time to adapt to a new eating pattern. Be patient and give yourself enough time to see results.

Eating Too Few Calories

Consuming too few calories can slow down your metabolism and make it harder to lose weight. Ensure you’re eating enough to support your metabolic needs. It is not just about eating fewer calories, it is about eating the right nutrients to maintain your health while also helping you lose weight sustainably. 

Lack of Nutrient-Dense Foods

Eating nutrient-dense foods helps you feel fuller longer and provides essential vitamins and minerals. Focus on a balanced diet rich in fruits, vegetables, lean proteins, and whole grains.

How do you break the weight loss plateau?

Breaking a weight loss plateau can be challenging, but with the right strategies, you can kickstart your progress again. Here are several effective approaches:

Change Your Eating Window: If you’re following an intermittent fasting plan, try adjusting your fasting and eating windows. Sometimes a different time-restricted eating schedule can help break the plateau. Experiment with shorter or longer fasting periods to see what works best for your body.

Increase Physical Activity: Boost your physical activity level to burn more calories. Incorporate different types of exercise, such as strength training, high-intensity interval training (HIIT), or cardio, to challenge your body in new ways and increase your metabolic rate.

Incorporate Strength Training: Building muscle through strength training can enhance your metabolism and help you burn more calories, even at rest. Aim to include weightlifting or bodyweight exercises in your routine a few times a week.

Check Your Macronutrient Balance: Ensure you’re consuming enough protein, healthy fats, and carbohydrates to support your energy needs and muscle maintenance. A diet high in lean protein can help preserve muscle mass and increase satiety, which is crucial for weight loss.

Stay Hydrated: Drinking water is essential for overall health and can aid in weight loss. Sometimes, thirst can be mistaken for hunger, leading to overeating. Aim to drink at least 8 cups of water a day or more if you’re active.

Get Enough Sleep: Lack of sleep can disrupt your hormones, increase hunger, and decrease your motivation to exercise. Aim for 7-9 hours of quality sleep per night to support your weight loss efforts.

Manage Stress: High stress levels can lead to hormonal imbalances and weight gain. Practice stress management techniques like meditation, deep breathing exercises, yoga, or spending time in nature to reduce stress.

Avoid Mindless Eating: Be mindful of your eating habits, and avoid eating out of boredom or stress. Focus on eating when you’re truly hungry and stop when you’re satisfied, not overly full.

Change Your Diet: Sometimes your body gets used to a particular diet. Try switching up your food choices to include more nutrient-dense options like whole grains, lean proteins, healthy fats, and plenty of vegetables and fruits. Avoid processed foods and sugary snacks.

Monitor Portion Sizes: Even healthy foods can contribute to weight gain if eaten in large quantities. Be mindful of portion sizes. 

Tips for weight loss success when intermittent fasting

Intermittent fasting (IF) can be an effective strategy for weight loss, but at the end of the day success depends on how you approach it. Here are some tips to help you achieve your weight loss goals with intermittent fasting:

Stay Hydrated: Drink plenty of water throughout the day to stay hydrated. This can help control hunger and improve overall well-being. Black coffee and herbal teas without added sugar are also good options during fasting periods.

Eat Balanced Meals: Focus on nutrient-dense foods during your eating window. Incorporate lean protein, healthy fats, whole grains, and plenty of fruits and vegetables to ensure you get all the essential nutrients.

Avoid Overeating: It can be tempting to overeat during your eating window, but this can negate the benefits of fasting. Pay attention to portion sizes and eat until you’re satisfied, not stuffed.

Plan Your Meals: Plan your meals and snacks ahead of time to avoid making poor food choices when you’re hungry. Having healthy options available can prevent you from reaching for fast food or high-calorie snacks.

Incorporate Physical Activity: Regular exercise can enhance your weight loss efforts. Aim for a mix of cardio, strength training, and flexibility exercises. Exercise can also help maintain muscle mass and boost your metabolic rate.

Get Enough Sleep: Aim for 7-9 hours of quality sleep per night. Poor sleep can increase hunger and cravings, making it harder to stick to your IF plan.

Manage Stress: High stress levels can lead to emotional eating and hinder weight loss. Practice stress management techniques such as meditation, deep breathing, yoga, or spending time in nature.

Be Consistent: Stick to your chosen IF plan consistently. Your body needs time to adapt to the new eating pattern, and consistency is key for long-term success.

Listen to Your Body: Pay attention to your body’s signals. If you feel excessively hungry or fatigued, it might be a sign to adjust your fasting window or increase your nutrient intake.

Avoid Sugary and Processed Foods: Take a closer look at your consumption of sugary snacks, processed foods, and beverages with empty calories. 

Eat Enough Protein: Protein is essential for maintaining muscle mass and keeping you full longer. Include sources of lean protein in each meal, such as chicken, fish, beans, or tofu.

Include Healthy Fats: Healthy fats, such as those found in avocados, nuts, seeds, and olive oil, can help keep you satisfied and support overall health.

Adjust Your Fasting Window if Needed: If you’re not seeing results or find the current plan unsustainable, experiment with different hours of fasting. Sometimes a small adjustment can make a big difference.

Stay Positive and Patient: Weight loss is a gradual process. Stay positive, celebrate small victories, and be patient with yourself. Consistency and persistence will pay off over time.

Side Effects of Intermittent Fasting

Intermittent fasting (IF) can have several side effects, especially when you first start or if it’s not done correctly. Here are some common side effects to be aware of:

Hunger and Cravings: One of the most common side effects is increased hunger, especially during the initial stages of intermittent fasting. This can lead to cravings for high-calorie or sugary foods.

Fatigue and Low Energy: As your body adjusts to a new eating schedule, you may experience fatigue, low energy levels, or feeling sluggish, particularly during the fasting periods.

Irritability and Mood Changes: Hunger and blood sugar fluctuations can cause irritability, mood swings, and difficulty concentrating. This is sometimes referred to as being “hangry.”

Headaches: Some people experience headaches, especially in the early days of intermittent fasting. This can be due to dehydration, low blood sugar, or caffeine withdrawal if you’re used to drinking coffee throughout the day.

Dizziness and Lightheadedness: Skipping meals can lead to dizziness or lightheadedness, particularly if you are not eating enough or staying hydrated.

Digestive Issues: Intermittent fasting can cause digestive problems such as constipation, bloating, or diarrhea. Changes in eating patterns and the types of food consumed during eating windows can affect digestion.

Sleep Disturbances: Some individuals find that intermittent fasting disrupts their sleep patterns, especially if they go to bed hungry or eat large meals late in the evening.

Nutrient Deficiencies: If not planned properly, intermittent fasting can lead to nutrient deficiencies. It’s essential to ensure that meals are well-balanced and nutrient-dense to meet your body’s needs.

Overeating During Eating Windows: There is a risk of overeating or binge eating during eating windows, which can negate the benefits of fasting and potentially lead to weight gain.

Muscle Loss: If not enough protein is consumed, or if caloric intake is too low, there is a risk of losing muscle mass instead of fat.

Dehydration: Fasting periods can sometimes lead to reduced fluid intake. It’s important to drink plenty of water throughout the day to stay hydrated.

Hormonal Imbalances: Intermittent fasting can affect hormone levels, particularly in women. This can impact menstrual cycles, fertility, and overall hormonal balance.

Risk of Eating Disorders: For some individuals, intermittent fasting can trigger or exacerbate disordered eating behaviors. It’s important to approach fasting with a healthy mindset and not use it as a form of punishment or extreme restriction.

Blood Sugar Fluctuations: People with diabetes or other blood sugar-related conditions may experience significant fluctuations in blood sugar levels, which can be dangerous.

Decreased Physical Performance: Some individuals may notice a decrease in physical performance, particularly in high-intensity or endurance sports, as the body adapts to using different energy sources.

Expected Weight Loss Results from Intermittent Fasting

Losing weight at a rate of one to two pounds per week is considered healthy and sustainable. Although this might seem slow, it’s the best way to achieve long term weight loss. Rapid weight loss often comes with health risks and is harder to maintain.

Intermittent fasting can support weight loss, but it’s not a cure-all. Research shows that significant weight loss isn’t the primary benefit of intermittent fasting, and substantial weight drops aren’t typically seen.

According to a systematic review of 40 different studies, intermittent fasting dieters typically saw a weight loss of 7 to 11 pounds over 2.5 months, which is an average of 0.7 to 1.1 pounds per week. While this is a healthy weight loss, you may not get to your goal weight by doing intermittent fasting alone.

Common Intermittent Fasting Schedules for Weight Loss

Intermittent fasting plans can be practiced in different ways. Among the many IF schedules, time-restricted eating and OMAD (one meal a day) are two of the most popular methods.

Here are the following intermittent fasting schedules:

Time-Restricted Eating

This involves fasting for a set number of hours each day and eating during a specific time window. Popular examples include the 16:8 method, where you fast for 16 hours and eat during an 8-hour window. Here are some common schedules and their potential benefits and drawbacks:


This is a great option for weight loss because it offers flexibility while still providing the benefits of fasting. It’s less restrictive and easier to maintain for most people.


More restrictive than the 16:8 schedule, this method involves an 18-hour fast followed by a 6 hour eating window. While it can help control overeating, it may be challenging to meet your calorie needs. This can potentially harm your metabolic health and make long-term weight loss difficult.


The most restrictive time-restricted eating method, with a 20-hour fast and a 4-hour eating window. This can be problematic for sustainable weight loss due to the difficulty of meeting nutritional needs in such a short time frame, which can lead to nutrient deficiencies and digestive issues.

OMAD (One Meal a Day)

This method involves eating one large meal per day and fasting for the remaining 23 hours. While it can simplify meal planning, it’s generally not recommended for weight loss because of the high risk of nutrient deficiencies and potential weight regain. Some studies also link OMAD to increased cholesterol and blood pressure levels, and there’s a lack of research on its benefits for humans.

Choosing the right intermittent fasting schedule depends on your lifestyle, preferences, and health goals. It’s essential to select a method that is sustainable and meets your nutritional needs to achieve long-term success.

how to speed up weight loss on intermittent fasting

Bottom Line

Intermittent fasting can be a great tool for weight loss. However, you aren’t guaranteed to lose weight just by fasting. Sometimes, your approach to fasting needs some adjustment. With a little exploration and fine-tuning, you should be able to find the right balance to keep going into the right direction of the weight loss and health benefits you are seeking.

Personally, I believe intermittent fasting is great for the body and can be amazing for your health. However be careful that you are not chronically under-eating and that you are filling up on wholesome nutritious and balanced meals during your eating window.

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