My BMR Is 1400: How Do I Lose Weight?

Losing weight with a BMR of 1400 calories is definitely doable, but it does come with a few challenges.

So, how do you lose weight with a BMR of 1400 calories? To lose weight with a BMR of 1400 calories, you need to determine your maintenance calories, factoring in exercise and daily activities. From there, create a sustainable calorie deficit. This will typically be 300-400 calories below your maintenance calories, which encourages your body to use stored fat for fuel.

If you have taken the step to determine your BMR, you’re already making progress in your weight loss journey.  From here, it is important that you set yourself up for short-term and long-term weight loss success because you want your hard work to pay off for years to come!

After reading this article you’ll feel more confident knowing:

  • If you measured your BMR correctly
  • If you can lose weight if you eat 1400 calories
  • If there’s a risk to eating under 1400 calories
  • How you can lose weight with a BMR of 1400
  • What to consider when exercising with a BMR of 1400

Did You Measure Your BMR Correctly?

If you calculated your BMR incorrectly, there is the possibility that you could be setting yourself up for a more difficult weight loss journey, as you may end up undereating or overeating.

To ensure the most accurate BMR calculation, you want to be sure that the calculator you used factors in your weight, height, gender, and age.

Additionally, if you are able to get a body fat estimate, you will be able to more accurately calculate your BMR and ultimately set yourself up for weight loss success.

Once you have an estimate of your body fat percentage, you will also have an estimate of your lean body mass (the weight of everything in your body that’s not fat), which will give you the most accurate BMR calculation.

It is important to acknowledge that these calculations will still be estimates, and you will likely need to make adjustments after you have tracked your calorie intake for 2-3 weeks and see how your body responds.

KEY TAKEAWAY: These calculations are important because the more data you have, the more accurate you can gauge your starting point, meaning that you will be able to avoid inadvertently over- or undereating. 

Will You Lose Weight if You Eat Your BMR of 1400 Calories? 

Yes, you will lose weight if you eat exactly your BMR of 1400 calories.  This is because your BMR is not the total number of calories that you burn in a day.  You also burn calories through movement and exercise, meaning that you will be in a calorie deficit as long as you don’t spend the day lying in bed.

Now, just because you CAN lose weight eating exactly at your BMR does not mean that this is the ideal calorie total for you to eat.  How many calories you should eat in a day will also be determined by how much activity you get in a day.

You can determine how many calories you burn in a day using this total daily energy expenditure (TDEE) calculator.  This calculates the calories you burn from physical activity and daily movement on top of your BMR and will help you to better determine what an appropriate calorie deficit will be.

If a 34-year-old, 154-pound woman who is 5’5” tall has a BMR of 1400 calories, then this is the number of calories that she must consume in a day for her body to function. However, the number of calories that her body needs increases if she adds any sort of activity to her day.

For example, if her activity level includes exercising 3 times per week, her TDEE is approximately 1925 calories. A calorie deficit of 400 calories (~20%) is considered to be a moderate to high deficit and will lead to weight loss.

While it is possible to create an even bigger calorie deficit, it is important to consider the long-term tradeoff of how sustainable it is to maintain that approach.

Are There Risks With Eating Under Your BMR of 1400 Calories?

Are there risks with eating under your bmr of 1400 calories?

There are risks to eating under your BMR. Your BMR is the minimum number of calories that your body needs in a day in order to perform necessary life-sustaining functions. It is not recommended that you consume less than this minimum requirement, as it could result in some negative side effects.

If you consume fewer calories than your body’s minimum requirement for an extended period of time, you may experience a number of these side effects:

  • Loss of muscle (resulting in lower metabolism)
  • Disrupted hormone balance
  • Impaired sleep quality
  • Significant loss of energy

1. Loss of Muscle (Resulting in Lower Metabolism)

If you continuously eat less than your BMR, your body will respond by slowing down your metabolism (use less energy to keep you alive) to conserve energy for essential bodily functions.  

Part of the way your body will accomplish this is to break down muscle and use that muscle for fuel.  When your body has less muscle, your BMR becomes lower, and thus your overall metabolism is decreased.

2. Disrupted Hormone Function

The effect of extreme calorie reduction is most pronounced in women, especially those of reproductive age. Biologically speaking, a lack of food indicates that conditions are not ideal for reproduction. Thus, regular hormone cycles can become disrupted, leading to a cascade of other unpleasant effects.

In addition to this, a high calorie deficit is also perceived as a significant stressor by your body, which will increase the production of cortisol.  This elevated cortisol is a biological response that can drive you to seek out food.  You may notice irritability, moodiness, mood swings, and powerful cravings as a response to this.

3. Impaired Sleep Quality

When you are under significant stress, this will impair the amount and quality of sleep that you get.  When you get insufficient sleep, it becomes more difficult to regulate appetite, cravings increase significantly, and maintaining a calorie deficit becomes a struggle.

This may also increase the risk of overeating episodes and could lead to a disordered relationship with food.

4. Significant Loss of Energy

To add to the list of negative side effects, you can imagine that if you are moody, irritable, and overtired, your energy levels are going to drop significantly.  This becomes counterproductive as it means you have less energy available to carry out an effective workout.

If you are unable to work out effectively, it becomes difficult to maintain your hard-earned muscle, which is a major part of your metabolism.

Related Article: Is 400 Calories A Lot? A Nutritionist Explains

How Do You Lose Weight With A 1400 BMR? (4 Steps)

How do you lose weight with a 1400 BMR? (4 steps)

There are 4 key steps to take to effectively lose weight with a BMR of 1400 calories:

  • Calculate your TDEE
  • Determine an appropriate calorie deficit
  • Calculate your ideal calorie and protein intake
  • Maintain your calorie deficit and consistency

1. Calculate Your TDEE

As I mentioned above, a TDEE calculator will estimate how many calories you’re burning through activity (exercise & non-exercise activity) on top of your BMR so that you can determine how many calories it takes for you to maintain your weight.

A simple way to do this right now (without having to use a TDEE calculator) is to use the Harris-Benedict Equation, which will help you calculate how many calories you are burning in a day through exercise on top of your BMR.

In order to do this, multiply your BMR with the number that accurately reflects your daily activity level:

  • Sedentary (minimal or no exercise): 1.2
  • Lightly active (light exercise or sports 1-3 days/week): 1.375
  • Moderately active (moderate exercise or sports 3-5 days/week): 1.55
  • Very active (intense exercise or sports 6-7 days a week): 1.725
  • Extremely active (Intense exercise + physically demanding job): 1.9

If we use our hypothetical woman from above (34 years old, 5’5” tall, 154lbs) and say that she is lightly active, we would multiply her BMR of 1400 by 1.375.

1400 x 1.375 = 1925 calories burned per day, on average.  This means that if she eats 1925 calories, she will maintain her current weight.

Once you know your TDEE, you can then move on to calculating an appropriate calorie deficit.

2. Determine an Appropriate Calorie Deficit

Once you have determined the average number of calories that you burn in a day via TDEE, you can properly calculate how many calories you will need to subtract from your daily intake in order to reach your weight loss goal.

When determining the calorie deficit you would like to implement, it’s important to consider the sustainability of the approach.  As a general rule, the more aggressive you make the deficit, the more difficult it will be to sustain it as a long-term approach.

If you would like to lose weight faster, you can use a more aggressive deficit of -400 to -500 calories per day. This type of deficit is appropriate if you have a higher body fat percentage or have a short timeline in which to lose weight.

For our example 34-year-old woman with a TDEE of 1925 calories, this would equate to eating between 1425-1525 calories per day.  While this may lead to more rapid weight loss in the short term, keep in mind it becomes more difficult to sustain as time goes on, and you are at higher risk of losing muscle with an increased deficit.

If you would like to preserve more muscle and take a more sustainable approach, you should use a moderate deficit of -200 to -300 calories per day.

This approach is much more sustainable in the long term, and you will likely experience less muscle loss, lower cravings, and more energy than if you were to use an aggressive deficit.

Using our 34-year-old woman again with a TDEE of 1925 calories, this would equate to eating between 1625 and 1725 calories per day.

If you only have a small amount of weight to lose, or you have a lower body fat percentage, you should take a conservative approach and keep your deficit between -100 and -200 calories per day to preserve as much muscle as possible.

This approach is the most sustainable of approaches, from the perspective of hunger and comfort, though it will take longer to reach your weight loss goals.

Check Out The Following Meal Plans:

3. Calculate Ideal Macronutrient and Protein Intake

Once you have chosen your calorie deficit for weight loss, you want to determine the specific types of calories that you want to consume. Ensure that you are getting a proper balance of protein, carbohydrates, and fat (i.e., macronutrients or macros for short) in order to meet your body’s daily requirements.

Some helpful numbers to know when calculating macronutrient ratios are that protein and carbohydrates have 4 calories per gram, and fat has 9 calories per gram.  You divide the number of calories by the number of calories per gram to determine how many grams of each macronutrient to consume daily.

Let’s say for our 34-year-old example woman chooses a moderate calorie deficit of 300 calories.  This means that she will aim to consume 1625 calories per day.

Knowing that, we can first determine how many grams of protein she should consume in a day.

Calculate How Many Grams of Protein to Consume Per Day

Generally, protein should be set to 1g per pound of bodyweight so that you’re providing your body with enough protein to encourage muscle mass retention while dieting. 

Since our hypothetical woman weighs 154lbs, she would aim to consume 154 grams of protein per day.

154 grams x 4 calories/gram = 616 calories of protein per day. For simple math, we could round up to 625 calories.

Calculate How Many Grams of Carbohydrate and Fat to Consume Per Day

To calculate the remaining calories, we will subtract the protein calories:

  • 1625 calories – 625 calories = 1000 calories left to divide between carbohydrates and protein

Once again, we will keep our math simple and suggest that our example 34-year-old woman would like to divide her remaining calories roughly equally between carbohydrates and fat.

CARBOHYDRATES: 500 calories / 4 calories per gram = 125 grams of carbohydrate per day

FATS: 500 calories / 9 calories per gram = 56 grams of fat per day

These ratios can be adjusted to suit personal preference, such as if you prefer a lower carbohydrate approach.

To learn more about how to calculate your daily macronutrient totals, check out Do Macros Matter for Weight Loss? (Yes, Here’s Why).

4. Maintain Your Calorie Deficit and Consistency

To successfully lose weight with a 1400 BMR, aim to be accurate and consistent with your efforts. If your calorie deficit is too low, you are less likely to stick to your diet. Choose a reasonable calorie deficit, eat meals with lots of protein and fiber, and make sure that you create meals that you truly enjoy.

To help you to be more accurate, I recommend a macro tracking app like MacroFactor that allows you to keep track of your intake and has a food database that is verified to be as accurate as possible. You can get two weeks free by using the code FEASTGOOD. Download on either the App Store or Google Play.

Apps Store
Google play

Using an app like this that is designed to be very user-friendly can set you up to be much more successful with your diet.

Exercising With 1400 BMR: What To Consider

Because it can be challenging to lose weight with a 1400 BMR, choose exercises that maintain muscle and increase calorie burn over the course of a day. Resistance training is highly effective at building and maintaining muscle and can increase your BMR over time.

One important factor to take into consideration when trying to lose weight is that if your exercise is too exhausting or intense it can increase hunger, causing you to overeat, or decrease non-exercise movement because it leaves you with no energy to fit in other activities throughout the day.

In turn, this will lower your overall TDEE (calories burned in a day).

Just as you want to choose a sustainable approach to your macros and calorie deficit, you want to ensure that you choose a sustainable approach to exercise and plan sufficient rest and recovery.

Final Thoughts

While this may seem like quite a bit of information to take into consideration, the key point to remember in all of this is that as long as you are creating a deficit through sufficient exercise and appropriate calorie restriction, you will experience weight loss with a BMR of 1400 calories.

Let’s get you in the best shape of your life. Sounds good?

What To Read Next

If you would like to gain even more confidence in your weight loss journey, here are some more resources that can help you reach your goals:


About The Author

Jon McLernon (aka Coach Jon)
Coach Jon

Jon McLernon (aka Coach Jon) is a Precision Nutrition Level 2 Certified Master Coach. With a background in chemistry and psychology, Coach Jon has a passion for supplement/nutrition science and behavioral psychology. When he’s not helping his clients crush their nutrition goals, he’s usually trying to wrangle a busy toddler (and get him to eat more veggies), or he and his Aussie wife are off on another globetrotting adventure!