How Long Does It Take To Lose 20 Pounds?

This content has been Fact-Checked by a Certified Nutritionist in our Publishing Team. Learn more here. Always consult a medical professional before commencing any diet.

How Long Does It Take To Lose 20 Pounds?

For many of us, weight loss has been a major problem. Whether you want to lose 5 or 20 pounds, it can be extremely challenging.

Losing even 1 pound can boost your confidence and make you feel more attractive.

But the question is how long does it take to lose 20 pounds?

The quick answer is 20 weeks.

However, your actual weight loss pace may depend on many factors, such as:

  • Genetic makeup
  • Metabolic rate
  • Gender
  • Age
  • Activity level
  • Diet

Unfortunately, no one can guarantee how fast you will start losing weight, however, you can follow the right guidelines and make sure that you are on the right path.

Read on to find out how long it will take you to lose 20 pounds fast and safe plus weight loss tips that actually work and get you results.

Before Anything – It’s Time to Assess Yourself

The first step towards losing weight is learning to accept and appreciate yourself. You are the one responsible for your body and health, therefore you shouldn’t blindly follow diets and forget about your well-being.

Let’s start with an honest self-assessment.

belly and measuring tape

Before trying a new diet, it is always a good idea to see your doctor first because this is a big change for your body, and you need to be prepared for it.

Maybe your doctor will make you recommendations about particular food items or workout exercises that may be too intensive for you, as a beginner.

It is crucial to assess your current lifestyle and ways to improve it. If it is mostly sedentary then admit that.

You need to be true and sensible about your current situation.

If you fail to acknowledge the problem then it is going to be much harder to move on in your weight loss journey.

In the same way, if you are active throughout the day, then you will need to consider that factor as well.

See below how you can work out how many calories you need to consume p/day in order to lose weight based on your lifestyle.

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How Long Does It Take To Lose 20 Pounds Calculator


According to the US government statement, an average man needs 2700 kcal and an average female 2200 kcal per day.

However, no one is the same – everything depends on the peculiarities of our organism: weight, height, body shape, physical activity, and overall general health. That’s when calculating BMR comes in to play.

Calculate your BMR

The Basal Metabolism Rate (BMR) calculates the daily number of calories required to keep your body functioning.

Even at rest, your body burns calories by performing basic life-sustaining functions, such as breathing and blood circulation.

Those calories are needed to produce energy, around 20% of which is used for brain metabolism. Besides the physical indicators (height, weight, etc.), your daily activity rate also affects your BMR.

Here is a formula to apply for calculating your BMR: (please note all data needs to be in pounds and inches)

For woman: 655.1 + (4.35 x weight) + (4.7 x height) – (4.7 x age)

For man: 66.47 + (6.24 x weight) + (12.7 x height) – (6.76 x age)

Example 1

Let’s calculate a young woman’s BMR

Age: 20
Height: 5 feet (60 inches)
Weight: 140 pounds

BMR= 655.1+ (4.35 x 140) + (4.7 x 60) – (4.7 x 20) = 1452.1

Please note that this is the number of calories you burn a day by doing nothing.

The Harris-Benedict Formula

Now let’s calculate BMR by using the Harris-Benedict Equation.

This formula shows the person’s estimated BMR corresponding to their activity level.

The Harris-Benedict equation = BMR x Activity factor

An activity factor is a number assigned to your amount of daily energy spent.

  • Sedentary (little or no exercise) = 1.2
  • Light exercise (approximately 2 to 3 days / week) = 1.375
  • Moderate exercise (approximately 3 or 5 days / week) = 1.55
  • Heavy exercise (6 or 7 days / week) = 1.725
  • Super heavy exercise (high-intensity exercise every day) = 1.9

Example 2

Let’s use this equation to calculate a young woman’s BMR from example 1. Assume she does light exercise 2 times per week, which means her activity factor is 1.375.

In our previous example, we have calculated that her BMR is 1452.1 (if she does nothing).

So, by multiplying her BMR with the corresponding activity factor we get the Total Daily Energy Expenditure (TDEE). In other words, the number of calories she needs to maintain her current weight.

TDEE = 1452.1 x 1.375 = 1996.6 calories.

Once you know how many calories you need per day, you can easily calculate how many calories you need to consume to lose weight.

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How Many Calories to Burn Per Day For Weight Loss

In order to lose weight, you need to follow a diet plan based on a little shortfall between your TDEE and the number of calories you actually consume.

To be able to do that, let’s understand how many calories a pound of body fat contains.

Taking into account that 1 pound equals 454 grams, pure fat contains 8.7-9.5 calories per gram and body fat tissue is 87% fat. We can conclude that a pound of body fat contains approximately 3500 calories.

So, creating a 3500 calories deficit may lead to the loss of 1 pound of fat in a week. Which is cutting 500 calories every day.

This is a suitable rate for a steady diet plan and safe weight loss, as doctors recommend not to drop calorie deficit below 1200 calories per day for women and 1800 calories per day for men.

Cutting more than 500 calories a day can be tempting however that can make your body think it’s starving and lead to the accumulation of extra fat.

So, try not to pass the minimum daily calorie intake boundary and you will achieve a consistent weight loss.

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Factors That Can Speed Up or Slow Down Weight Loss

stressed woman


It turns out that genes may affect your weight loss. If both of your parents are genetically predisposed to gain weight, then probably it will be challenging for you to reduce your weight.


Studies have shown that it becomes harder to lose weight with age. Although you can lose weight at any age, changes in metabolic rate, hormones, and many other factors resulted by age can determine your weight loss pace.

Eating and physical activity habits

High-protein and low-carb diets can help accelerate fat loss. Protein is the most essential nutrient that helps to suppress your appetite.

A high-protein diet increases your metabolism and therefore the number of calories burned per day. Also, if you are active throughout your day can help a lot for your weight loss.


When you don’t get enough sleep, you lack energy and tend to eat more. Maintaining a regular sleep habit can prevent you from reaching out for excessive amounts of food and caffeine.


When you are anxious, your blood sugar drops and you crave for food. Also, cortisol, the stress hormone, causes that belly fat to be stored in the abdominal area and it becomes quite challenging to lose weight. According to this study, chronic stress is associated with obesity.

Weight Loss Tips

fitness class

Starving yourself while dieting is not the best option. There are some easy ways that can speed up your weight loss.

Avoid sugar

Avoid sweets, desserts and sugary beverages such as carbonated drinks, fruit juices (even natural ones are full of sugar), chocolate milk, energy drinks, etc. Always read the label before buying a product, you will be surprised how many canned products including canned vegetables have added sugar. Opt for fresh fruits and vegetables instead.

Lift weights

Resistance training will help you build muscle strength and endurance. It may also increase your metabolism by 7% and helps you lose 4 pounds of fat.

Eat healthy snacks

Almonds, sliced apples, whole wheat crackers are some good healthy snack examples, that you can eat several times a day. Always carry a healthy snack on you to avoid falling into temptation when hungry. Also, avoid processed and packaged foods as it has high salt, sugar, and fat content.

Drink more water

Drinking water can help you burn more calories as it boosts metabolism by 24-30%. Leave a bottle of water at work, by your bed at night and even in your bag when going out. Follow these tips to help you keep up with your water intake goals. The increase in drinking water is associated with weight loss according to this study.

Get more sleep

According to studies getting proper rest reduces the number of calories consumed by 6%!

Eat slowly

Eating foods slowly helps to regulate food intake by causing a feeling of fullness. Never eat in a rush, or in front of the tv! Instead, find someone to eat with you 🙂

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Plan Your Meals

plan your meals ahead

In order to get rid of body fat, you need to change your diet and eating habits. It is never late to start practicing mindful eating 🙂

Below you can find a one-day diet plan. It is healthy, tasty and contains only 1218 calories.

Also check out our fat burning foods guide: How To Lose 5lb Fast With Negative Calorie Foods

Breakfast (248.5 calories)

Blueberry & Honey yogurt

  • 285 grams of non-fat plain Greek yogurt
  • 76 grams of blueberries
  • 1 tsp. honey
  • 1/2 Tbsp. almonds

Snack (57 calories)

  • 1 small green bell pepper, sliced (45 g)
  • 1 Tbsp. hummus

Lunch (389 calories)

White Bean & Avocado Toast

  • 1 small slice toasted whole-wheat bread
  • half of an avocado, mashed
  • 45 grams of mashed white beans
  • Salt and pepper

Add avocado and white beans on your toast, season with salt and pepper.

Snack (48 calories)

  • 95 grams of raspberries

Dinner (476 calories)

Total intake: 1218 calories, 78 g protein, 95 g carbohydrates, 31 g fiber, 64 g fat, 1,301 mg sodium

You can find similar meal plan options here.

Calorie Tracking Apps

To help you keep on track of your daily calorie consumption here are some awesome calorie counting apps.

These apps will help you calculate the number of calories in each product you eat and suggest tips on healthy recipes and daily workouts.

Some of these apps even offer lovely communities to help support each other during their weight loss journey.

Here is a list of several apps:

  • MyFitnessPal – Free, Paid versions at $9.99/month or $49.99/year (iOS and Android)
  • FatSecret – Free (iOS and Android)
  • Lose it! – Free, Paid versions at $39.99/year (iOS and Android)
  • MyNetDiary-Free, Paid versions at $39.99/year  (iOS and Android)

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How Long Does It Take To Lose 20 Pounds By Working Out?

fit woman push ups

If you purely rely on exercise and workout, then burning 3500 calories per week requires 5 hours of swimming, 3h 50m of running and 5h 30m of cycling. By doing one of these activities every week, you will lose 20 pounds in 20 weeks!

Of course, the best is to combine regular moderate daily workouts with a healthy diet. This way you will not only cut your body fat effectively but also will be able to maintain your new weight.

Here is a table listing calorie amount burned by doing different activities for 30 minutes.

Calories Burned Table

Drastic changes in your lifestyle may be frustrating, so simply listen to your body and determine how much exercise it needs,. Decide how much calorie intake you will need to reach your weight goal.

Quality and Quantity

Wrong dieting can do you more harm than having extra pounds. So, besides calorie restriction, don’t forget to focus on calorie quality too. Apart from having fewer calories, your diet should also be nutritious and help you stay healthy.

There are nutrient-dense calories and empty calories. Empty calories may lead to weight gain, as they have high calorie-density.

Examples of empty calorie foods:

  • Soft drinks
  • Energy drinks
  • Ice cream
  • Fast food
  • High-fat cheese
  • Sausage
  • Other foods that contain a high level of sugar and solid fats.

You can consume the same amount of calories that have higher nutritional value and will have a positive impact on your health in the long-term.

Nutrient-dense calorie foods include:

  • Whole grains
  • Fruits
  • Vegetables
  • Oatmeal
  • Lean protein

Your health depends a lot on what you eat. So, cutting back on calories may lead to your goal weight, but in the long run, it may cause many health conditions. Therefore, educate yourself and find out about high-quality foods. It’s never too late to adjust your diet and start eating healthy.

Risks of Losing Weight Too Quickly

feeling unwell

1# May cause loss of muscle

A low-calorie diet may help you decrease your weight fast by losing muscle and water. Which is not the same as losing fat. Yes, you will see a different number on your scales but you will not look fit and healthy.

2# You may slow down your metabolism

Eating fewer calories may result in burning 23% fewer calories. Metabolism slows down because of muscle loss and the decrease of hormones that regulate metabolism.

3# You may have nutritional deficiencies

It is hard to consume enough vitamins and nutrients when you are on a low-calorie diet. Nutritional deficiency may cause:

  • Hair loss
  • Weak bones
  • Poor immune system
  • Extreme fatigue
  • Anemia

4# Other consequences

  • Dehydration
  • Dizziness
  • Feeling cold
  • Irritability
  • Constipation or diarrhea

Plus, the lost weight is more likely to be regained as losing weight fast is not a consistent method and it is very hard to maintain it.

So, How Long Does It Take To Lose 20 Pounds?

The recommended amount is losing 1-2 pounds per week, which means you will lose 20 pounds in 10-20 weeks. This depends on your commitment and health.

Before starting any kind of diet, it is best to make sure your body is ready for changes. Go see your doctor and check your health.

Combining healthy diets with short daily exercise is the best way to achieving long-term results.

It takes 4-6 weeks to notice the first results of working out. Be patient and focus on steady weight-loss, as the final outcome is worth the wait.

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This content has been Fact-Checked by a Certified Nutritionist in our Publishing Team. Learn more here.

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