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How Many Calories Should You Eat for Fat Loss?

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This is it. You’ve decided that now is the time to lose weight, shred body fat and give your lifestyle a complete overhaul.

And what’s the biggest determining factor in whether or not you’ll carve out a six pack, reveal those shapely shoulders and uncover those athletic legs?

Calorie intake.

And in this article we’re going to tell you exactly how many calories you need to eat for fat loss.

There’s no need to be hesitant and there’s no need to leave it to chance any longer.

Read on to find out how to change your lifestyle for the better and lose fat today…

What are Calories?

A food calorie is a unit of measurement. It commonly refers to the energy needed to raise 1 kilogram of water by 1 degree Celsius. This is where the ‘kilo’ comes from in the term kilocalorie (kcal).

Calories are the most important determinant of weight gain and loss. And whilst other factors may play a small role in body mass changes, the amount of calories you eat on a daily basis will decide whether or not your weight goes up… or down.

Calorie intake

This is the energy you receive from the food that you eat, specifically from three macronutrients – carbohydrates, fats and proteins. 

It’s worth noting that these don’t all provide you with the same amount of energy. The Atwater system – which was the original research into energy from food – suggests that:

  • For every gram of protein and carbs you eat you get 4 kcal
  • For every gram of fats you eat you get 9 kcal
  • And not that it gives you nutrients as such but it’s worth knowing that alcohol is worth 7 kcal per gram

Calorie output

The calories you burn each day is what you you’d call energy expenditure.

This is made up of:

  • Basal metabolic rate (BMR)
  • Thermic effect of food (TEF)
  • Physical activity and NEAT
  • Exercise

Your BMR refers to the calories you need to ensure your brain, heart and other organs can function properly. It is typically measured when you are at rest so as to accurately measure the energy you need to purely let your body ‘tick over’. It accounts for around 60-75% of most people’s overall energy burn each day.

TEF refers to the energy you need to digest and absorb incoming food. It only accounts for about 5-10% of the energy you burn each day but i still a contributing factor. Each macronutrient has a different TEF value, with protein needing much more energy to digest than either carbs or fats.

Physical activity is anything that isn’t classed as exercise. And non-exercise activity thermogenesis (NEAT) is classed as anything where your body moves but you aren’t sleeping, being physically active or playing sports.

Together, these could be walking your dog, shopping, cleaning, fidgeting, tapping your foot and so on. This can account for a surprisingly high 50% of daily energy burn if you are an active get-up-and-go kind of person.

And of course, exercise refers to any structured activities such as going to the gym, playing sports and so on.

Total daily energy expenditure

When you add up your BMR, TEF and physical activity levels you’ll end up with your total daily energy expenditure or TDEE.

And what happens to your body is really just a balancing act between your TDEE and the amount of food you eat…

Scales of liberty to resemble calorie intake and output

Key Point: Calories are a measure of food energy. And as a unit of energy, it can be measured as both intake and output.

Energy Balance Determines Weight Loss or Gain

The calories-in/calories-out (CICO) model suggests that body weight is a matter of thermodynamics. That weight gain and loss is a balancing act between how many calories go in your body and how many you burn off.

Too much energy leads to weight gain…

When you take on more energy than you burn off each day you achieve a calorie surplus. Why’s it called that? Because your body has taken all of the energy it needs from incoming food and there’s some spare – a surplus.

And what does your body do with this spare energy? That’s right. It stores it as fat, ready for a rainy days when you might need it as back up energy.

note – as far as your body is aware, you’re still a hunter-gatherer, unsure of where the next meal is coming from. It’ll therefore do everything it can to store excess energy as fat in case of famine or low energy availability.

A calorie surplus is often referred to as positive energy balance.

…and an energy deficit leads to weight loss

On the flip side, if you don’t eat as much as you’re burning off each day, your body will start to use that stored fat to make up the difference.

You’ll do everything you can to store fat, but the minute your body needs energy and there isn’t enough around, you’ll break into your fat cells and make a little withdrawal – much like you’d do at the local ATM.

A calorie deficit is often referred to as negative energy balance.

Maintenance is like sitting on the fence

But what if you take on the same number of calories as you burn off each day? Nothing.

You’re providing your body with just the right amount of energy it needs to go about its day-to-day tasks.

This is what’s known as maintenance calories.

Woman working out her daily calorie needs on a tablet computer surrounded by healthy food

How Many Calories Do You Need?

If we use all of the information we’ve discussed so far we’re well on our way.

The very first thing you need to do is choose a daily calorie intake that allows you to fall into a calorie deficit. This is how…

What is your daily calorie requirement?

The first thing you need to do is work out your BMR. This is simple as we’ve already provided you with a calculator below. All you need to do is input your height, weight and gender and it’ll use its inbuilt algorithm to give you a baseline to work with.

Let’s say for example you were a 35-year old female who weighted 155 pounds. The calculator would give you a BMR of around 1680 kcal.

Factor in your activity levels

BMR is the number of calories you’d need if you were to sit still all day,every day. It’s no use to us yet because we’ve not factored in how active you are.

The next stage is to calculate your activity levels by selecting one of the following:

  • Little or no exercise
  • Easy exercise (2-3 times per week)
  • Moderate exercise (4 times per week)
  • Very active (5 times per week)
  • Day by day exercise
  • Day by day intense exercise (twice daily)
  • Daily exercise and physical job

The key thing here is you need to be honest. Because if you’re not your calorie count will be way off.

Let’s say that our 35 year old female is fairly active and comes under the easy exercise category. Again, we use the calculator and let it do it’s thing.

And we’re now given a total daily energy intake of 1923 kcal.

What does this mean? It’s the total number of calories that this person would need to eat to stay at the same weight. Not lose, not gain, but fall under maintenance calories.

So How Many Calories to Lose Fat?

Now that we’ve worked out your maintenance calories all we need to do is work out an optimal energy deficit – remember, you’ll only burn fat with a negative energy balance.

And here’s where it all becomes very individualistic because what you can tolerate as your deficit will be different to others.

Currently, the research suggests that a deficit of around 20-25% from maintenance calories is enough to stimulate fat loss, whereas you might be happier and respond slightly better either a slightly higher or lower number than that.

How much fat will you lose?

At a 20-25% deficit it estimated that you will lose around 1-1.3 lb per week. Possibly even higher than that if you have more fat to lose. 

This would be more if you were to take your deficit even higher, but the chances are you’ll lose a lot more muscle mass if you aren’t on a very high protein diet, find it harder to keep to, and suffer from low energy.

Healthy woman running down the pier with music player strapped to her arm

Key Point: A calorie deficit of around 20-25% lower than maintenance will lead to around 1-1.3 lb of fat loss per week, maybe even higher.

Can Exercise Help You Lose Weight?

Of course.

Every time you move, walk, run, jump or lift weights you burn energy. And if you add all of the calories you burn from physical activity up, that can be a significant amount.

But it’s worth noting that if you compare calories burned from exercise to food intake energy, exercise isn’t the most efficient way of achieving a calorie deficit.

For example, let’s say you go for a bike ride and burn 300 calories. For the average person that’d take around 30 or so minutes dependent on the intensity.

Now how long would it take you to eat 300 calories? If it was an English muffin at 395 calories, probably around 2 minutes.

It can be much easier to avoid extra calories than it is to exercise them away.

Eat less or exercise more

And that’s where motivation, habit and preference come in.

You might be the sort of person that doesn’t like exercise and would do anything to avoid that 30 minute bike ride. If that’s the case, then shaving off energy intake by making wise food choices is a good option.

On the other hand, you could exercise regularly, monitor how many calories you’ve burned in each session, and use that extra energy to eat a little more but still maintain a negative energy balance.

It’s really a matter of personal choice. But again, if you don’t fall into a deficit you’ll not drop body fat.


  • Step 1: Use the online calculator to work out your basal metabolic rate. Simply add in your gender, weight and height and we’ll do the rest.
  • Step 2: Add in your activity level – be truthful.
  • Step 3: Subtract 20-25% from this number to find your fat loss sweet spot.