Lose 20 Pounds in a Month: Is It Possible? Is It Safe?

lose 20 pounds in a month

If you’re like the majority of my clients who want to lose weight, you want results, and you want them quickly! But it’s not enough to just lose 20 lbs, you need to make sure that you keep it off for good!

So, can you lose 20 pounds in a month? Losing 20 lbs in a month is unrealistic and could have negative health implications. It would be more realistic to lose 20 lbs over 12-16 weeks. You can do this by creating a calorie deficit of 500-800 calories per day by eating less, exercising more, and increasing your activity levels throughout the day.

I’ll outline why it is unsafe to try and lose 20 lbs in a month, help you set more realistic timelines, and explain exactly how to lose weight. I’ll also share a sample workout plan to help you look and feel your best throughout the process.

Did you know that when trying to lose weight, you must ensure you are lifting weights, building muscle, and not losing strength? On average, a new Fitbod user who trains 3 times a week for about 45 minutes will see a 34% strength increase after 3 months. Try Fitbod for free.

What Would It Take To Lose 20 Pounds In A Month?

It is generally understood that one pound of fat equals 3,500 calories. This means that to lose 1 lb, you would need to be in a 3,500-calorie deficit (accumulated deficit).

So, what would it take to lose 20 lbs in a month?

To lose 20 lbs in one month, you must have a monthly calorie deficit of 70,000 calories. This equates to being in a calorie deficit of ~ 2,350 per day. So, if you eat 3,000 calories daily, you would only be able to eat 650. If you normally eat 2,350 calories per day (or less), you would not be able to eat for an entire month.

Seems pretty unrealistic right? Well, that’s because it is! 

What would be more realistic is to aim to lose 0.5-1% of your body weight per week, meaning most people can lose between 4-12 lbs in one month. 

I prefer to use percentages when talking about the rate of loss because the heavier you are, the faster you can lose weight safely. 

For example, someone who is 150 lbs should not aim to lose 12 lbs per month, as this is a rate of weight loss of 2% per week; however, someone who is 350+ lbs or more may be able to lose 12+ lbs in a month. 

Is It Safe To Lose 20 Pounds In A Month?

is it safe to lose 20 pounds in a month

Losing 20 pounds in a month is not just unrealistic but it’s also unsafe because you would have to severely restrict your intake, which can lead to nutrient deficiencies, muscle loss, and a slower metabolic rate. Additionally, it increases your risk of yo-yo dieting and disordered eating.

Rapid, extreme dieting has a slew of negative side effects, many of which have been well-documented in scientific literature.

Some of these negative side effects include:

  • Increased Risk Of Gallstones. According to the American Journal of Medicine, a total weight loss of 1.5 kilograms (~ 3 lbs) per week is the absolute fastest rate of weight loss that should be done with obese individuals.

Non-obese (clinically diagnosed obese) and overweight individuals should aim for slower rates of weight loss per week. The AMJ found an exponential increase in gallstone formation at quicker rates. 

  • More Likely To Regain Weight. Research has repeatedly shown that fast weight loss and highly restrictive dieting results in regaining most, if not all of the weight loss in a very short time following the termination of the restrictive diet.

This often leads to yo-yo dieting, severe weight fluctuations, and potential eating disorders.

  • Potential To Develop An Eating Disorder. Researchers found that disordered eating (extreme weight loss dieting) increased the risk of both men and women developing an eating disorder (bulimia, anorexia, or binge eating disorder).

If you struggle with an eating disorder, please seek out help from a medical professional or therapist. If you are unsure if you have one, speak to your medical professional and be honest about your eating habits. Nobody should feel ashamed or alone if they have an eating disorder. Please seek help.

Need a workout program? Try Fitbod for Free.

How Long Would It Take To Lose 20 Pounds Safely?

Most people could lose 20 lbs in 12-16 weeks (3-4 months) with consistent workouts, adopting an active lifestyle, and a moderate calorie deficit (eating fewer calories than your body needs to maintain weight). 

You should strive to lose 0.5-1% of your body weight per week, as this is a safe and sustainable rate of weight loss that can help you maintain lean muscle mass and lose predominantly body fat.

Results may vary depending on:

  • How heavy you are: people who have more to lose can lose more weight in less time
  • How lean you are: leaner individuals will lose weight slower, as they do not have as much weight to lose
  • How consistent you are: inconsistent workouts and calorie intake will result in slower weight loss

Losing 20 lbs in a more realistic time frame will help you look and feel a million times better than if you try to do it in a month, and you will be more likely to keep it off for good.

Related Article: The Best 3-Days Per Week Weight Loss Workout Program

How To Lose 20 Pounds

how to lose 20 pounds

Now that I’ve convinced you that a more realistic approach is worth it, you’re probably wondering how to lose 20 lbs. 

To lose 20 lbs, you’ll need 3-4 months of consistent adherence to a calorie deficit, exercise program, and increased non-exercise activity (i.e. daily walks, increased step count). 


To lose weight you have to be in a calorie deficit, meaning you have to eat fewer calories than your body needs to maintain weight. 

The number of calories that you need to maintain your weight is equal to your Total Daily Energy Expenditure (TDEE). Your TDEE is based on your physical activity levels (averaged throughout the week from workouts), your NEAT (nonexercise activity thermogenesis), age, sex, and body composition. 

To calculate your TDEE and find your maintenance calories, you can use this calculator.

Once you have estimated your TDEE, you will decrease that number by 5-10% to create a calorie deficit from diet alone.

For example, if you calculate your TDEE (and maintenance calories) to be 2500 calories, then your calorie target to be in a calorie deficit should be between 2250-2375 calories per day.

Remember that the goal is to lose around 0.5-1% of your body weight per week, so if you’re losing more than this, add more calories back to your target. If you’re losing less than this, reduce your calorie target further (5-10%) OR increase your activity level.


Although calories are most important for losing weight, you should also prioritize your protein intake to encourage your body to retain (or build) muscle mass as you lose weight. 

My recommendation is to aim for 1 gram of protein per pound of body weight while hitting your calorie target.

For example, if you weigh 160 lbs then you should aim for 160 grams of protein per day.

If you’re hitting your protein target and your calorie target you will be set up for success and you can let your carbs and fat intake fall where they may. There is insufficient evidence to support low fat vs low carb vs fasting is more effective for dieting. 

Ultimately, the best diet is one that someone can adhere to for the long term (months to years) that supplies fruits, vegetables, quality protein sources, healthy fats, and grains.


When looking to lose weight, you should be exercising to help increase your overall energy expenditure (burn more calories per day) as well as to help build and preserve lean muscle mass. 

When losing weight, you do not want to lose muscle mass as this will decrease your metabolic rate (fewer calories burned at rest), diminish physical performance, and negatively impact your physique.

The most important type of exercise while dieting is strength training because this type of activity encourages your body to retain (and build) muscle mass. 

Aim to lift weights 3-4 days a week, incorporating heavier (5-10) and moderate (10-20) rep ranges. Workouts should consist of 3-5 sets of 5-10 exercises per session, lasting roughly one hour (more or less). 

You can also add in some cardiovascular exercise to help speed things up by increasing the number of calories you’re burning each day.

For example, you could add 1-3 sessions per week of 20-30 minutes of biking, running, swimming, or other heart-pumping activities.

However, remember that cardiovascular activities should be supplementary and not the main priority while losing fat.

Related Article: How to Workout Twice Per Day for MORE Weight Loss


NEAT stands for non-exercise activity thermogenesis, which means the number of calories your body burns while performing daily activities, like working, fidgeting, household chores, or grocery shopping.

NEAT is the reason why you’re often told to park further away, take the stairs rather than the elevator, and pace while talking on the phone. All of these increases in calorie expenditure add up over time to help you lose weight.

Most people focus on diet and workouts when trying to lose weight, but what you’re doing with the other 23 hours a day that you are not in the gym has a dramatic effect on your weight loss.

Make an effort to increase your NEAT to help keep you within the 0.5-1% loss each week. 

TIP: Increasing your daily step count to 8,000+ steps per day (not including exercise) is one of the best things you can do to nudge weight loss in the right direction when progress slows.

Looking for a workout program? Try using the Fitbod App, which will design your program based on your logged training data and goals. The workouts will adapt automatically to your levels of recovery and rate of progress. With over 600 movements and exercises videos, you can be sure to perform the movements correctly for optimal results. Take the guesswork out of your workouts. Try Fitbod for free.

Sample Workout Plan To Help Lose 20 Pounds

sample workout plan to help lose 20 pounds

To help set you up for success on your journey to lose 20 lbs, I’ve created two sample workout routines that you can start implementing today.

Each workout is around 75 minutes and includes weight training and cardiovascular exercise to help increase calorie output while also encouraging muscle retention and growth.

Each workout is total-body, as this will ensure you can train the muscles multiple times a week without going into the next workout extremely sore.

The following workouts are not found in the Fitbod app, but each exercise can be found in the app. You can use these workouts as templates to build your training plan in the app.

Day 1: Strength & Cardio Focus

  • Rowing Warm-Up: Perform this progressive intensity warm-up, one time through. This should take no longer than 10 total minutes.
  • Perform 150m on the rower at a moderate to hard pace, and then rest for 1 minute.
  • Then, perform a 250m row at a moderate to hard pace, and then rest for 90 seconds.
  • Lastly, row a 500m at a moderate to hard pace, and then rest for 2 minutes before moving on.
  • Weight Circuit #1: Perform one exercise every minute, completing 10-15 reps per exercise. This should take you 20-30 seconds to complete. You should then have the remaining 30-40 seconds of the workout to rest and move on to the next movement. 

Do three total rounds of this circuit, which should take a total of 18 minutes. Once you are done, clean up your area, and then move on to the next circuit.

  • Weight Circuit #2: Perform one exercise every minute, completing 10-15 reps per exercise. This should take you 20-30 seconds to complete. You should then have the remaining 30-40 seconds of the workout to rest and move on to the next movement. 

Do three total rounds of this circuit, which should take a total of 18 minutes.

  • 20 Minutes of Incline Walking: Set the incline at 10-15% and walk at a challenging pace. Your heart rate should be above 70% of your max but no higher than 85%. 

To find your max, take 220 beats per minute – your age (so someone who is 40 has a maximum heart rate of 180 beats per minute). They would want to work at an intensity with a heart rate between 125-155 beats per minute.

Day 2: Strength Focus

The below workout is a more traditional type of workout that has you perform one or two exercises at a time, resting 45-90 seconds between sets. The key with this workout is to focus on using as much weight as possible for the rep range and aim to build strength and muscle. 

While Day 1 can also help build muscle, its main goal is to push the overall amount of work you are doing, which means you are using less weight. Use today to build strong muscles and progress as you can every week by adding or doing the same weight for a few more reps.

  • Assisted Pull Up Machine: 4 sets of 8-12 reps, directly into assisted dip machine
  • Assisted Dip Machine: 4 sets of 8-12 reps, resting 90-120 seconds after each set
  • Leg Press: 4 sets of 8-12 reps, directly into dumbbell walking lunge

About The Author

Mike Dewar

Mike holds a Master’s in Exercise Physiology and a Bachelor’s in Exercise Science. He’s a Certified Strength and Conditioning Specialist (CSCS), USA Weightlifting Advanced Coach, and has over 10+ years of experience working with collegiate athletes, national level lifters, and beginners alike. Mike is Founder of J2FIT Strength and Conditioning, a growing global training company with gyms in New York City, Cincinnati, and online offering personal training, online custom coaching programs.