Calorie Deficit For Beginners (How it works?)

In this article I will explain everything you need to know about calorie deficit and how you can do it without worrying about counting calories, measuring food portions, or cutting on carbs.

What Is A Calorie Deficit?

A calorie deficit is a moment when energy expenditure exceeds energy from consumed calories and creates a negative energy balance. In the absence of calorie supply coming from the food, the body starts to utilize internal sources of energy coming from stored body fat.

In other words, when you eat less than your body needs, your body will switch and metabolically “adapt” to continue to deliver essential calories for the basic metabolic processes.

How Many Calories Does My Body Burn Doing Nothing?

On average, your body can burn at rest anywhere from 1,600 to 1,800 calories for males, and 1,200 to 1,400 calories for females. The number of calories burned while doing nothing will vary, depending on the type of food you eat, your activity level, lean body mass, and more.

Here are the processes that cost you calories, even when you don’t move your finger.

  • BMR (basal metabolic rate)

This is around 70% of your total calories burned during the day. That includes your breathing, oxygen transport, cognitive functions, etc. The majority is taken by your muscle mass.

  • TEF (thermogenic effect of food)

This is around 10% of your daily calories burned. This is your digestion, food breakdown, enzyme production and nutrient transportation.

  • EAT (exercise activity thermogenesis)

This is your physical activity that is planned, like gym workout, jogging or yoga. Depending on your freqnecy, it can take around 5-10% of your total calorie intake.

  • NEAT (non-exercise activity thermogenesis)

This is your non planned physical activity like walking around house, up and down the stairs, carrying groceries, playing guitar, running around kids, food prep, cleaning house, etc.

What Is A Calorie Surplus?

A calorie surplus is when you eat more calories than your daily energy expenditure consumed. When calories from food surplus calories that your burned, all the excess calories will get stored as fat and be ready to use in the form of a stored energy source.

How To Create A Calorie Deficit?

You can create a calorie deficit only when you reduce the amount of food that you eat, you start to move and exercise more or both. The easiest way to create a calorie deficit is by a combination of nutrition intervention together with adding more physical activity.

How To Be In A Calorie Deficit In Three Steps

Eat fewer calories than usual

You can do it by calculating the number of calories that you normally eat and based on those numbers reduce the food among. Another way to get to a calorie deficit, without calorie counting is by intermittent fasting.

Add more daily exercise

Adding more like walking, swimming, or cycling will add extra calories burned to your exercise activity thermogenesis. Staying more active and moving around will add extra calories to your non-exercise activity thermogenesis. Add some resistance training which will increase your lean muscle mass.

Do a combination of both

The most effective way is by reducing the total amount of food together with adding more exercise.

How Do I Know If I’m In Calorie Deficit?

The most effective way to know if you’re in the calorie deficit is by calculating how many calories you’ve consumed and subtract that from your BMR and activity level. Activity levels you can measure using fitness trackers and BMR you can calculate using the formula.

Some of the good calorie trackers are:

How To Calculate Calorie Deficit With BMR

You can calculate calorie deficit with BMR using the Mifflin-St Jeor formula:

  • For men (10 × weight in kg) + (6.25 × height in cm) – (5 × age in years) + 5
  • For women (10 × weight in kg) + (6.25 × height in cm) – (5 × age in years) – 161

NOTE: To accurately calculate your BMR you need a strict laboratory setting and perform the test in a pone position after 12 hours of fasting.

That’s why those calculations aren’t the most accurate, but they can give you the benchmark of your daily energy expenditure, without physical activity.

Related article: Does Calorie Deficit Work Without Exercise?

How Many Calories Do I Need For A Calorie Deficit?

For a calorie deficit you need to eat 300 – 500 calories below your basal metabolic rate. For people who are physically active, they can eat more calories as the body will subtract the extra calories burned. However, there are ways to be in a calorie deficit without calculating your calories.

  • For people who are physically active, 250 – 300 calorie deficit is enough to maintain weight loss
  • For people who are sedentary 500 calorie deficit recommended

How To Make Sure I’m In a Calorie Deficit?

The easiest way to make sure you are in the calorie deficit is by counting calories, measuring food portions, counting food points, practicing intuitive eating, or doing intermittent fasting. Some people prefer counting calories, where others prefer intuitive eating and intermittent fasting.

  • Counting calories

Counting calories is the most accurate way to know the calories in your foods, but it’s not the most comfortable and sustainable methods. In general, people don’t like to count calories on a daily basis.

  • Measuring food portions

Measuring food portions is another way to make sure you’re in calorie deficit. It requires you to use a food scale, palm size charts, or rely on the plate size as your cues.

  • Counting food points

Some diets like The Zone or Weight Watchers work by calculating not the calories, but the food points. They assign specific number to each food, and based on your weight goals, you get the daily points limit.

  • Practicing intuitive eating

Intuitive eating relies on listening to the internal cues of the body and making sure you’re in a calorie deficit by eating when you feel physically hungry and stop eating when you’re no longer hungry. This method is extremely effective, as long as you know how to do it.

  • Intermittent fasting

Intermittent fasting works by reducing food amount by skipping meals, reducing the feeding window, not eating for several hours per day, or designate a couple of days of the week where you don’t eat anything at all. There are several ways to do intermittent fasting.

Related article: 5 Ways To Be In A Calorie Deficit Without Being Hungry

Signs Of Calorie Deficit

There are no universal signs of a calorie deficit. Every person responds differently to not eating. One of the signs you know you’re in a calorie deficit is hunger. Hunger tolerance varies for different people, so it is very subjective to know if you’re in a calorie deficit or not.

People have a different understanding of hunger. Some people may exaggerate when describing themselves as

  • “I’m starving”
  • “I’m feeling hungry”

Where in reality they may feel just a little bit uncomfortable.

So hunger feeling is not something that we should run away from. It is just as normal to feel hungry as to feel happy or sad. But people have a hard time differentiating between physical hunger and emotional hunger (source).

What Is Physical Hunger?

Physical hunger is the signal stimulated by the gastrointestinal peptide hormone ghrelin coming predominantly from the stomach. Prolonged fasting leads to increased levels of total ghrelin which can result in hunger signals, stimulation of appetite, and eating behavior.

Things that can influence hunger

  • Hormone levels (testosterone, menopause, menstrual cycles)
  • Biological rhythm (sleep, traveling, working time)
  • Individual (GI health, medications, thirst)

What Is Emotional Hunger?

Emotional hunger is the strong signal that psychological needs aren’t sufficiently met. In times of high stress, emotional discomfort, or uncomfortable feelings, people continue to eat as stress relief or reward. Emotional eating is using the foo to make yourself feel better.

Things that influence emotional eating

  • Negative emotions (we eat to feel better)
  • Negative situations (stressful and uncomfortable moments)
  • Irrational beliefs (negative self-talk, negative self-image)

Do I Need To Count Calories To Be In A Calorie Deficit?

You don’t need to count calories to eat less and be in a calorie deficit. Counting calories is just one of many methods that is used to estimate how much food you’ve consumed, and therefore, how much food you should or should not be eating.

Counting calories can tell us how much calories is in the specific food item, but it doesn’t tell us about:

  • Why we eat
  • How fresh is food
  • How processed is food
  • How nutrients changed during harvesting, manufacturing, storing and cooking
  • How much we absorb
  • Synergistic effect of nutrients

How To Have A Calorie Deficit Without Counting Calories?

Here are 7 ways to have a calorie deficit without counting calories:

  • Eat slowly for 20 minutes
  • Eat more proteins
  • Eat mindfully without distractions
  • Eat when relaxed, not when stressed out
  • Eat more high-satiety foods
  • Eat when physically hungry
  • Stop eating when no longer hungry

On top of that, you can try to experiment with intermittent fasting. There are several protocols that help you eat less, get in a calorie deficit, without counting calories.

Related article: Can You Lose Weight Without Being In A Calorie Deficit?

Can You Be In Too Much Of A Calorie Deficit?

You can be in too much of a calorie deficit when you eat not enough calories for a long period of time. After a prolonged calorie deficit, the body starts to down-regulate, lowers the metabolic rate, and hits the weight loss plateau. One of the effective methods to overcome a plateau is calorie cycling.

Calorie cycling is when you alternate days of low energy intake with days of high energy intake.

  • 5 days a week calorie deficit
  • 2 days a week calorie maintenance / surplus

Or you can alternate one day after another. One of the popular methods of intermittent fasting ADF (alternative day fast) works by alternating days of fast with the days of feeding:

  • 36-hour fasting window
  • 12-hours feeding window

How Much Of A Calorie Deficit Is Too Much?

Too much of a calorie deficit is when you eat 1000 calories below your basal metabolic rate for a prolonged period of time. After long-term dieting, in response to weight loss, the body decrease resting metabolic rate decreases gut motility and protein synthesis.

But those numbers will vary, depending your lifestyle, hunger tolerance, weight loss goals and your environment.

What Happens If You Have Too Much Of a Calorie Deficit?

When you have too much of a calorie deficit your body starts to feel fatigued, low energy levels, difficulty in concentration, constant hunger, sleep problems, and stress. The excessive calorie deficit can result in unwanted eating behaviors like impulsive eating or overeating.

Here’s how it works:

  • Too much calorie restriction leads to food deprivation
  • Food deprivation from foods that you like often leads to more stress.
  • A tipping point of stress can cause the binge eating effect.

That’s when people start jo-jo dieting. First, they restrict their diet too much, then as a result of high stress, they break down and binge (source).

How Do You Get Energy In A Calorie Deficit?

You can get energy in a calorie deficit by eating highly satisfying foods that are high in protein, fiber, and water. Proteins have the highest satiety and will balance the glucose levels. Fiber and water lower calorie density and leads to proper hydration and regularity.

Other things that can give you energy boost while doing calorie deficit are:

  • Resistance training
  • Cardio training
  • Yoga or stretching
  • MCT oil

Should You Be In A Calorie Deficit Everyday?

You don’t have to be in a calorie deficit every day to see the results. Many forms of intermittent fasting or calorie cycling work by alternating days with normals calorie intake with the days of calorie deficit. This approach makes the process more suitable for people and more sustainable.

Making an alternative days of calorie restriction make the process easier.

  • It’s more realistic
  • Can be used long term
  • Can be adjusted with the personal and professional needs
  • It doesn’t create too much stress

Which means it will combat the cravings for the foods you want to eat and therefore reduce the stress.

Related article: Does Calorie Deficit Work With Unhealthy Food?

How Long Should You Be In A Calorie Deficit?

You should be in a calorie deficit as long as you can reach your weight loss goal. For people who want to lose 20 pounds, 12 weeks calorie deficit should be enough. For people who want to lose 50 pounds, 24 weeks or more of a calorie deficit should be enough.

In general, reasonable range of a weight loss is around:

  • Excellent (losing 0.5 to 1% of body fat every 2 to 4 weeks)
  • Average (losing 0.5% of body fat every 2 weeks)
  • Slow (losing less than 0.5% of body fat in 4 weeks)

How Long Is Too Long To Be In A Calorie Deficit?

Being too long in a calorie deficit is when you already reached your optimum weight, but you continue to diet. After you reached your goal you should be eating in calorie maintenance. Having a reasonable goal can help you map out the time required to get to your results.

  • Calorie deficit calories should be below your BMR
  • Calorie maintenance should be slightly above your BMR, depending on your physical activity


Here are some of the typical problems people may have:

Why am I not losing weight even though I have a calorie deficit?

You may not be losing weight on calorie deficit because you either miscalculated your calories and you eat more, you’re mindlessly overeating on some days of the week, or it hasn’t been long enough to start seeing the results.

Why can’t I lose weight in a calorie deficit?

You can’t lose weight in a calorie deficit because you are eating too much, you already lost weight which lowered your basal metabolic rate, or you are too early in the process. In general, having a food journal helps to track foods you eat and improves the awareness of the actual food intake.


Calorie deficit may seem like a challenging task. But in reality, is a straightforward process that requires patience and consistency. The process of weight loss doesn’t happen overnight, and the results will be different for different people.

Having a food journal can help where you document all the process and keep your measurements handy, so when it comes tot he times of doubt, you can always look upon the progress you’ve already made.

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.

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