How To Lose Weight With 1000 Calorie Deficit (Full story)

Take a look at the picture below.

things i eat during 1000 calorie deficit

This is an example of my 1000 calorie deficit diet plan that allowed me to lose over 27 lbs in less than three months.

Today I will share my experience of what happens if you have a 1000 calorie deficit (pros and cons), and whether is it okay to eat so little for a long period of time.

What does a 1000 calorie deficit mean?

In general, a 1000 calorie deficit means eating 1000 calories below your total daily energy expenditure (TDEE).

TDEE is the number of calories the body burns, including:

  • metabolism;
  • physical activity; and
  • digestion.

For instance, if your TDEE is 2,500 kcal, a 1000 calorie deficit means eating around 1,500 kcal.

Why 1000 calorie deficit is effective?

Simply put, eating 1000 kcal less than normal is a powerful tool to create a negative energy balance, and drives weight loss.

Heck, it’s like you’re eating almost half of your calories per day. (So it can create fantastic results.)

However, It’s not easy.

(So it’s not for everyone.)

More on that later.

What does a 1000 calorie deficit do?

As a whole, being in a 1000 calorie deficit switches the body from using glucose (as a source of calories) to using fatty acids from adipose tissue.

As a result, body fat is being utilized for energy, which creates weight loss.

It’s fast. 1000 calorie deficit can shave off 2 pounds per week (or more).

Which is why it’s so appealing.

And, it can be done with a combination of diet and low-intensity exercise.

(If you plan to do calorie deficit together with exercise, I recommend doing resistance training and steady-state cardio to help you maintain lean muscle mass).

Is a 1000 calorie deficit safe?

In the short term, doing a 1000 calorie deficit is achievable (and safe). It can teach you to manage your hunger and lower calorie intake (even after you finish dieting).

However, in the long term, it can lead to metabolic adaptations and a weight loss plateau (more on that later).

Here’s how it works.

The longer you stay in a large calorie deficit:

  • You may have more cravings for foods you like; and
  • You may have more stress because of those cravings.

Which can result in overeating.

1000 calorie deficit can be stressful

Some people, who already have a lot of stress going on in their life, can find dieting to be even more stressful.

For instance, people who experience:

  • Relationship stress (long-distance relationships, conflicts, loneliness, etc.);
  • Caregiving (looking after parents, kids, etc.);
  • Financial stress (debt, low income, etc.);
  • Work stress (especially the 996 workers);
  • Poor social support (lack of like-minded community); and
  • Health problems (illness, injury, etc.)

And, if that’s the case, even a small calorie deficit may be too much to handle, right now.

That’s why some people thrive on a 1000-calorie deficit (or more) while others panic, freak out, and raid the pantry to overeat.

1000 calorie deficit is not for everyone

During periods of energy restriction, the body starts to create a series of homeostatic and metabolic adaptations,” says nutritionist and health consultant from Alicante, Mario García Martínez-Gómez, BSc.

In his recently published narrative review on Metabolic Adaptation, the expert listed some of the metabolic changes that happen during calorie restriction.

For instance:

  • Changes in hormonal balance. Hormonal changes in leptin, ghrelin, insulin, etc.
  • Reduced energy expenditure. The body burns fewer calories, also known as adaptive thermogenesis.
  • Psychological changes. Some people may experience stress and anxiety.

“The magnitude of these changes can depend on how long you maintain energy deficit,” explains the expert.

The expert highlights that “higher deficits done for longer durations can increase adaptations and promote larger homeostatic responses”.

In other words, the longer you stay in deficit, the harder it gets.

1000 calorie deficit may not be ideal for the long term

Doing 1000 calorie deficit can be an excellent way to drive short-term weight loss, but it may not be the best idea for the long duration.

“Higher energy deficits may lead to several physiological changes that may encourage weight to regain,” says an endocrinologist and head of the Obesity Research Group at the University of Melbourne, Priya Sumithran, MD.

“Changes in energy expenditure, metabolism, and hormone pathways involved in appetite regulation, can persist, even beyond the initial weight loss period,” says Dr. Sumithran.

Dr. Sumithran suggests that “with the right strategies, you can overcome these physiological changes.”

(Let me show you how.)

But first.

Will I lose weight with a 1000 calorie deficit?

Yes, you can lose weight with a 1000-calorie deficit. (Heck, I lost over 27 pounds.)

When energy expenditure exceeds energy intake over a given period of time, the body weight goes down.

Eating 1000 calories below your maintenance threshold call upon stored fat reserves to be used as energy and make up the difference.

(Doesn’t matter how you cut it.)

Your body needs calories for 24-hour operations.

  • Digestion;
  • Cognition;
  • Breathing;
  • Blood flow; and
  • Movement.

And even when you don’t eat.

The show must go on.

So energy will come from stored fat.

1000 calorie deficit but not losing weight

Everything is possible.

The only way to not see the results while being in a 1000 calorie deficit is by inaccurate calculations of calorie needs, (aka exceeding calorie intake), or being too early in the process to notice any visible changes.

Let’s break this down.

Inaccurate calculations

How do you know you’re in a 1000 calorie deficit?

(Hint: Probably from online TDEE calculators.)

However, some online TDEE calculators can be inaccurate becasue they use generic equations. Yes, they use age, gender, and body weight (sometimes even fat mass, height, and waist-to-hip ratio).

“To establish your metabolic rate you need more than an arithmetic formula,” says an obesity expert and associate professor at the City University of New York, Nasim S. Sabounchi, Ph.D.

Dr. Sabounchi explains that “to know exactly how much energy your body burns in 24 hours at rest, you need a controlled laboratory setting with direct or indirect calorimetry.”

Otherwise, you just guessing.

Eating more calories

It happens more often than not.

(People don’t really know how much they eat.)

Because they’re busy, stressed out, or distracted.

In fact, the USDA Center of Nutrition Policy did a fascinating study, and compared people’s perceptions versus the actual servings of foods.

(See below.)

how much people eat on 1000 calorie deficit

According to a USDA study, people usually have a completely different perception of how much food they eat.

  • people overestimate how many vegetables, fruits, and meats they eat (compared to reality); and
  • people underestimate how much sweets and grains they consume.

Being too early in the process

This one comes from our expectations.

From the logical side, we all know weight loss takes time.

But from the emotional side, we want results to happen now.

We hear that someone lost a crazy amount of weight in a short period of time.

Or we see some photoshopped before and after pictures.

Or even some unrealistic ads on the internet.

And if we don’t digest that with a big grain of salt.

It can mess up our brains.

The reality is that any weight loss process will take a lot of time (which is why people find it hard to stick to it).

There are more reasons

There may be more reasons why you’re not losing weight while being in 1000 calorie deficit.

  • you may calculate wrongly your calorie intake; or
  • you’re having some mindless eating episodes that you don’t include in your numbers.

If that’s the case, the easy way to fix that problem is by using the food journal.

(No. You don’t have to write down calories.)

Just write down everything that you eat, and your thoughts about food.

This way you may increase your self-awareness.

How much weight can you lose with a 1000 calorie deficit?

It depends on how long can you do it.

Here you can find the video from Paul Revelia where he explains how much weight he lost during a 1000 calorie deficit.

Paul also covers what to do when you notice a weight loss plateau, and gives some practical solutions.

On a 1000 calorie deficit, you can lose 2 – 2.5 pounds of body weight per week (on average). Taking that into perspective, if you diet for 3 months, that can result in 24 to 30 pounds of weight loss.

How to do a 1000 calorie deficit?

Follow these steps to make your 1000 calorie deficit not only effective but also sustainable (and safe) in the long term.

Use intermittent fasting

The easiest way to do a 1000-calorie deficit per day (without counting calories) is to implement intermittent fasting.

There are several ways to do intermittent fasting:

  • one meal a day;
  • alternative day fast;
  • Warrior Diet; and
  • skipping meals

(There are some more.) My point is that these protocols help you to eat less, without counting calories or measuring food portions.

I don’t say calorie counting doesn’t work. (It does.)

In fact, counting calories is one of the most effective ways to control food intake and lose weight (for some people).

But it’s boring.

And in the long term, it creates more anxiety and stress.

Where on the flip side.

Intermittent fasting works just as well.

But you don’t have to stick to the “rules” or numbers.

You just either eat (or you don’t).

Check out my guide on how to do one meal a day for beginners to learn more about how you can get to a 1000 calorie deficit without worrying about calories.

Physical activity

Doing 1000 calorie deficit together with exercise may be an effective way to suppress your appetite. Plus, the lean body weight you have, the more calories you can burn at rest.

I like to do strength training followed by medium-pace walking. Heck, I even covered in how I lost weight by walking 10 km a day in my article.

(Check it out.)

Apart from walking, you can try

  • yoga or pilates;
  • cycling;
  • swimming; and
  • hiking.

For me, walking wins becasue it helps me to control my appetite. (And trust me, on a 1000 calorie deficit, you can feel hungry.)

So you want to use anything you can to increase your hunger tolerance and feel less hungry. (I choose to exercise.)

Eat more proteins

Adding more protein to your meal can increase your satiety and help you combat food cravings.

Once you feel more confident in getting more proteins, try to improve by choosing leaner protein sources (e.g., substitute a grilled protein instead of a fried one.)

High protein helps to maintain the rates of muscle protein synthesis and reduce muscle protein breakdown, according to Martínez-Gómez.

Stay hydrated

According to the British National Health Service (NHS), drinking plenty of water is important not only for your health but for weight loss, too.

(The last thing you want is to be dehydrated.)

Caffeine is another appetite suppressant, but drinking too much coffee may lead to abdominal pain, according to NHS.

Is a 1000 calorie deficit too much?

People who have higher hunger tolerance and stress tolerance can sustain longer (and higher) energy deficits.

However, people who have lower hunger and stress thresholds should cycle high-calorie days with low-calorie days.

It all depends on who you are.

How you react to physical hunger from your gut will determine:

  • How long can you do it; and
  • How often can you do it?

1000 calorie deficit is too much for me, what to do?

To be clear, there is nothing wrong with admitting that 1000 calories are too much for me.

If that’s the case, then follow these steps.

Eat more calories

If 1000 calorie deficit is too much, simply add more calories. Start by doing a 500 calorie deficit and see what happens. If that’s too much, go ahead and eat 250 calories more.

Cycle your days

Cycling your days means you eat 1000 calorie deficit on 2-4 days in a week. (Alternate high-calorie days with 1000 calorie deficit days.)

For the rest of the days, you eat as normal.

This may help you work on your hunger and stress tolerance.

To learn more on how to do intermittent fasting for 5 days a week, check out my guide.

Will I lose muscle on a 1000 calorie deficit?

It’s possible, depending on the duration.

You can lose muscle on a 1000 calorie deficit only when you don’t eat enough protein. Muscle loss occurs when muscle protein breakdown exceeds muscle protein synthesis.

This usually happens on hypocaloric diets, without adequate intake of dietary proteins.

In my article, I explain how you can do calorie deficit together with a high protein diet, and still build muscle mass.

You can build muscle in a 1000 calorie deficit

Achieving an optimal muscle protein synthesis on a 1000 calorie deficit can be done.

Check out this video from coach Christian Thibaudeau on building muscle while cutting.

“Optimal muscle protein synthesis requires regular protein intake throughout the day and progressive overload,” says Christian.

Christian suggests that “to build muscle while being in deficit you should:

  • eat high-protein meals every 3-4 hours;
  • combination of strength training with high and medium loads (65−85% 1RM);
  • train with high volume (28−30 sets/muscle/week); and
  • have balanced nutrition around workout time with a high-leucine and glucose.

(So It can be done.)


Being in a 1000-calorie deficit is not easy. In the short term, it is a fast track to losing 2 – 2.5 pounds of body weight per week.

But in the long term, it can create more stress and anxiety.

Which means it is not sustainable.

At least not for everyone.

Michal Sieroslawski

Michal is an exercise physiologist (MSc) and a veteran endurance athlete. He loves to experiment and share his successes and failures to help busy men and women who want to lose weight.

Leave a Reply

Your email address will not be published. Required fields are marked *

Recent Posts