Do Low Calorie Diets Slow Your Metabolism? Debunking the Myth!

By Lily •  Updated: 04/04/23 •  8 min read

Low-calorie diets have been a popular weight loss strategy for decades, but there is a common concern that they may slow down your metabolism.

The idea is that if you eat too few calories, your body goes into “starvation mode,” causing your metabolism to slow down and making it harder to lose weight.

So, do low-calorie diets slow your metabolism? Not if the low-calorie diet is done correctly. But if done in an unhealthy way, it certainly can!

In this blog post, we’ll explore the science behind low-calorie diets and metabolism, and whether or not there is any truth to the idea that low-calorie diets can slow down your metabolism. 

Let’s dive in and debunk this myth once and for all!

Do Low Calorie Diets Slow Your Metabolism

What Is a Very Low Calorie Diet?

Counting calories is a good thing when you are trying to lose weight, but there is the potential to go too far. 

A very low calorie diet is one that slips below the recommended daily caloric intake for your body. Typically, this means taking in fewer than 1,000 calories a day.

Eating too few calories can send your body into starvation mode. So it is super important that you keep track of the number of calories you are consuming every day.

As your body struggles to get enough calories to generate energy, it can cause your metabolism to slow down significantly. This can make it harder to lose weight and keep it off.

However, if you are eating normally, then you shouldn’t have to worry too much about going below this amount. 

You can absolutely get enough calories to meet your body’s needs, even on a plant-based diet.

Keep reading to learn about several effective ways to avoid throwing your metabolism off.

What Factors Influence Your Metabolism?

The first thing you’ll want to know is that multiple factors influence how fast your body burns calories for energy. For instance, having a larger body size tends to result in a higher metabolism.

The simplest way to look at this is to understand that your body requires more energy to move more mass.

As you trim down, your metabolism will naturally slow, but the impact should be slight. It’ll also adjust to the rate that you body needs to maintain its energy levels.

Being male or female can also influence your metabolism.

Men tend to have more muscle mass. Since muscles require more energy, this can cause them to burn calories faster. Women can compensate for this by doing strength-training exercises.

Your metabolism also slows down as a normal part of the aging process. This is mostly caused by a decline in your muscle mass.

Eating more plant-based proteins and exercising can reduce the effects of aging on your metabolism when you are trying to lose weight after 40.

What Are Empty Calories and How Do I Avoid Them?

When you are watching calories, you want to make sure that the ones you take in are providing the highest amount of nutrients possible. This helps your body to avoid going into starvation mode.

Empty calories are ones that provide temporary bursts of energy but that don’t give your body the fuel it needs for a strong metabolism.

They lack vitamins, minerals and fiber. You can often recognize food with empty calories because it tends to have high fat and sugar contents.

Alcoholic beverages and sugary sodas are common sources of empty calories.

If you are trying to cut back on your caloric intake and regularly consume these beverages, then this is a good place to focus, since it won’t take away from your body’s need for nutrients.

What Are the Risks of Not Eating Enough Calories?

The answer to do low calorie diets slow your metabolism also comes with the need to make sure that you understand the risks of trying a starvation diet.

On top of making it harder to lose weight, restricting calories too much can also interfere with your ability to maintain your health.

Your body gets nutrients from your food that help you to maintain proper bone structure, fight off illnesses and have the energy to complete your daily activities.

Watching what you eat is often more important than solely focusing on the calories.

What Are The Signs and Symptoms of a Slowed-Down Metabolism?

There are several signs and symptoms that may indicate a slowed-down metabolism.

One of the most common is weight gain or difficulty losing weight, even when following a low-calorie diet and exercising regularly.

Other symptoms may include fatigue, feeling cold, constipation, dry skin, and hair loss.

Additionally, a slowed metabolism can lead to hormonal imbalances, which can cause irregular periods in women and decreased libido in both men and women.

It’s important to note that these symptoms can be caused by other factors as well, so it’s always a good idea to speak with a healthcare professional if you’re experiencing any of these symptoms.


How Many Calories Should I Eat for Weight Loss?

You will need to create a calorie deficit to lose weight. The good news is that this is simple to do when you already know your recommended daily caloric intake.

Just start by using a calculator or chart to figure out how many calories someone your age and sex needs to maintain their body weight based upon your activity level.

Then, calculate that you need to take in 500 to 1,000 calories less to lose weight. Just make sure that you don’t go below the mark for passing into a too low-calorie diet. That is not healthy!

What’s the Best Way to Track Your Daily Caloric Intake?

Counting calories doesn’t have to be a major hassle. There are several fitness apps available that you can use to enter information in about what you eat based upon the type of food and serving size.

One of my favorite apps is MyFitnessPal, it’s free and it already has tons of data, making it that much easier for you to know for many calories per day you are consuming.

This is yet one of the many areas where eating a plant-based diet is helpful, since the calories in a typical piece of fruit or vegetable will remain the same versus trying to figure out how many a slice of pie contains.

What Else Can I Do to Speed Up My Metabolism?

Now that you know the truth behind do low calorie diets slow your metabolism, you may also be ready to do things to increase your body’s metabolic rate.

One way to do this is to eat fruits and vegetables that are high in fiber and low in carbohydrates. Low-carb vegetables take longer for your body to break down, which uses more energy and fewer calories will be converted to fat.

Keep in mind that you’ll want to be cautious when you choose plants and vegetables for your diet. Some can have sneaky sources of calories.

For example, avocados have high amounts of fat that can add up fast if you eat them regularly. However, they can also keep you full longer, so there are gives and takes. Find out what works best for your body!

You’ll also want to exercise for at least 30 minutes to an hour each day to burn off excess calories.

Exercising also sends signals to your brain that it needs to rev up your metabolism to meet the energy demands of a higher level of activity.


How Can I Repair Metabolic Damage?

Repairing metabolic damage involves a combination of strategies that aim to increase your metabolism and improve your overall health.

One of the most important steps is to increase your calorie intake gradually, allowing your body to adjust to a higher level of energy consumption.

This can be done through a process called “reverse dieting,” which involves slowly adding calories back into your diet while monitoring your weight and body composition. 

How to Maintain a Strong Metabolism?

Maintaining a strong metabolism requires a combination of healthy habits and lifestyle factors.

One of the most important steps is to consume a balanced diet that is rich in whole, unprocessed foods, including plenty of protein, fiber, and healthy fats.

Additionally, regular exercise, including both cardiovascular and strength training, can help to build lean muscle mass and increase your metabolism.

It’s also important to prioritize getting enough sleep and managing stress levels, as both of these factors can impact your metabolism and overall health.

Finally, staying hydrated and avoiding excessive alcohol consumption can also support a healthy metabolism.

By adopting these healthy habits and making them a part of your daily routine, you can help to maintain a strong metabolism and support your overall health and well-being.


Low-calorie diets can be an effective tool for weight loss, as long as they are implemented in a healthy and sustainable way.

However, don’t ever eat less calories than your body needs to function at its best! That is not the right way to lose weight.

To support a healthy metabolism, it’s important to focus on consuming a balanced diet that is rich in whole, unprocessed foods, engaging in regular exercise, prioritizing sleep and stress management, and staying hydrated.

By adopting these healthy habits, you can support a strong metabolism and promote overall health and well-being.


Hi, I'm Lily! Like you, I have struggled with my weight. It was not an easy journey but I was able to lose 40 pounds and have kept it off for 14 years. My goal is to share with you all the research, tips, and tricks that I have learned over the years to help you lose weight also.