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Losing weight with a calorie deficit

Losing weight is very simple in theory, but often hard in practice. To consistently lose weight, one of the simplest methods is to be in a daily calorie deficit. That means that your daily calories are 300–500 kcal under your maintenance calorie level (the level that maintains your current body weight) which causes weight loss. You cannot notice these results on a daily basis due to so many fluctuating variables (such as stress, movement, diet, sleep, and water), so the results of a calorie deficit are most accurate and noticeable on a weekly scale, such as a weekly average.

People have different goals when it comes to losing weight. However, it is generally best to lose weight with the goal of being healthier, and not just to look thinner. There has been a growing trend with people wanting "revenge bodies" after a bad breakup or wanting to be thinner to get the attention of someone. If your motivations align with these kinds of goals, you are setting yourself up for failure. Not only is letting someone else influence you like this very unhealthy, but this will also cause problems with essential components of weight loss such as intrinsic motivation. Losing weight for a more healthy life is a big journey you should only embark on it for the good of yourself or those close to you.

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How to do a calorie deficit

To guarantee the results of a proper, accurately measured calorie deficit, you need the following items:

  • A general estimate of a daily calorie target (that will become precise later) based on your individual attributes like age, sex and physical activity level

  • A kitchen scale to weigh your food so that you're not reliant on inaccurate estimations

  • A calorie tracking app to speed up the process significantly (such as MyFitnessPal or Lifesum)

  • A weight scale to track changes in your body weight

  • Patience to get weekly averages so that you can adjust your calorie target

Start off by figuring out your calorie deficit estimate online. Use a calorie calculator such as the one at Calculator.net and input all the relevant details: Rate your exercise activity very modestly as very many overestimate this factor. Determine your calorie target as either the "Mild weight loss" (~250 kcal deficit) or "Weight loss" (~500 kcal deficit) level as in the picture below. If you tend to struggle with hunger a lot, go with the Mild weight loss level. Remember that online calorie calculators are relatively inaccurate as they cannot account for important factors such as genetics, stress or sleep so adjusting your calorie target after the first week is crucial.

Note that the calculator results are only approximate estimates, and your real deficit can differ significantly. Please exercise caution if you are given an unusually low estimate.

Here's an example of what I got after inputting my information to the calculator – thus my 500 kcal deficit would be 2,262 kcal per day.

Now that you have established your first target deficit, you need a kitchen scale and a calorie counting app to help you in the process. A kitchen scale costs about $15-40 and is generally quite durable. I will be using MyFitnessPal in this example as it is commonly used and appreciated – although it does offer a premium membership, I find the free version sufficient for a calorie deficit.

When counting calories, start with something really rudimentary to learn the ropes: I will demonstrate tracking a simple breakfast meal of oatmeal porridge with picture instructions below.

  • ¹First get your box of oatmeal and your kitchen scale ready.

  • ²Put the bowl (or whatever you want to use as a weighing dish) on the kitchen scale and press the "TARE" button – this resets whatever weight is on the scale to zero so that the weight of the weighing dish isn't accounted for when you're weighing the oatmeal.

  • ³Add as much oatmeal as your calorie target allows – for the simplicity of this demonstration I'm going to add exactly 100 g of oatmeal (370 kcal).

  • Most calorie calculator apps (MyFitnessPal and Lifesum included) offer the convenient option of scanning the package barcode so that all you need to do is just input the measured amount of grams (or other portions) and the app will track the number of calories.

Now that the oatmeal is measured, I can go ahead and cook this 100 g of oatmeal for a total of 370 kcal (according to the nutritional information on the package, which is automatically tracked by the app after inputting the amount in grams).

Track every food ingredient from protein (e.g. chicken) to carbohydrate source (e.g. pasta, rice) so that your calorie calculator app displays no more than your calorie deficit target as your total measured daily calories. Remember that condiments such as ketchup, mayonnaise and other extras (butter, grated cheese) add to this target so you should count them in as well.

You should quickly get the hang of how many calories you should eat per day, but in case you're unsure, divide your daily deficit by three for your breakfast, lunch and dinner to be the same size. In my case my theoretical 2,262 kcal daily deficit would be three meals of 754 kcal each. You can freely adjust these proportions such as by making your breakfasts lighter if you don't like to eat much in the mornings. You can move the "unused" calories to lunch and dinner as long as you're not exceeding your calorie goal. Alternatively, you can also opt for slightly smaller meals if you prefer to have a snack between lunch and dinner to help with the cravings.

Track your progress by weighing yourself on the weight scale every week (or every day for more precision) so that the conditions are as identical as possible: I prefer going on the scale every morning after my first visit to the bathroom so that my stomach is empty and the result as consistent as possible.

Don’t look at the daily changes for progress as weight fluctuates heavily: you could have done your best dieting and your weight might still go up due to fluctuations out of your control. You can only see accurate progress looking at the weekly average in weight as time evens out the errors caused by weight fluctuation:

If your weekly average body weight does not decrease or increases, it means that you're either not tracking your calories accurately or that your calorie target is inaccurate. In either case you need to decrease the daily calorie target by 250 kcal if your weight has not decreased at all on a weekly basis. Depending on your pace, a decrease of 0.5–1 lbs (or 0.25–0.5 kg) per week is a great pace. If your weight loss rate exceeds 1 lbs / 0.5 kg per week, you risk muscle atrophy (breakdown of your muscle mass) and risk getting excessive cravings that increase the risk of binging – go for consistency, not intensity, as dieting is playing the long game.

Water weight: the reason why most fail dieting

The human body consists of roughly 70 percent water, with the exact amount varying greatly between individuals. As we discussed above, weight fluctuates a lot every day. Much of this fluctuation is caused by water weight, and the term refers to additional water stored in the body with certain nutrients like carbohydrates and sodium (salt).

When people start dieting, the first thing to go is the excess water stored in your body. This sudden drop in water weight is caused by sudden changes to carbohydrate, sodium, or fluid intake, which makes sense as people often reduce their carbohydrates and salty processed foods at the start of a diet. As the body is self-regulating, it seeks to adjust this imbalance, quickly restoring the water weight back to a normal level, which shows up on the weight scale as increased weight.

This water weight adjustment demotivates the dieter immensely, as first they had noticed the scale go down (due to the drop in water weight which did not affect actual fat mass) and then suddenly going back up. It is as if the scale was punishing them for good behavior. This is thankfully just the start of a diet: Once the body has accustomed itself to the different amounts of carbohydrates and sodium, fat mass starts slowly decreasing. But this fat reduction, the actual progress, happens after this water weight adjustment that demotivates so many people. This is why staying consistent and being almost excessively patient with dieting is crucial for results. I've simplified this process with a graph below:

An illustration on water weight progression

Important observations about a calorie deficit You can technically eat whatever you want as long as you are in a calorie deficit. This means you can eat what you want as long as you're within the threshold of your daily calorie target – Yes, you could lose weight with a McDonald's diet or eating chocolate and pizza every day. The major downside to this approach is that as processed food is so poor in nutrients you will feel quite bad eventually as your body is not getting enough necessary micronutrients from fast food.

Processed foods are also fairly energy-dense so they will fill your calorie target up faster while leaving you hungry without filling your stomach as much as vegetables, for instance. I recommend investing on the quality of your diet: eating vegetables provide important micronutrients and help fill you up easily for relatively few calories. A more varied diet in general is healthier regardless of if you are on a diet or not.

If you're coming from a resistance training background (bodybuilding, gym, strength training), you might be assessing the benefits between prioritizing protein intake or the calorie deficit. If your goal is to permanently lose weight, then prioritizing protein is not ideal. However, if you are aiming for strength, opting for sufficient protein while sacrificing the deficit might be worth it as your muscles become stronger and eventually require more maintenance calories to maintain, so it will even out to some extent. This is not a good approach short-term, though, and only works if executed very consistently over a very long period of time.

A common challenge with a calorie deficit is the feeling of hunger and constant cravings: A good way to mitigate this is getting on a high protein diet for increased satiety on top of distributing your meals so that they’re evenly split over the span of the day – I used to make the mistake of having a big breakfast and lunch and then a tiny dinner (a "front-heavy" diet), which made my evenings horrible as I experienced constant cravings and hunger. Drinking plenty of water, and especially having 1–2 glasses before a meal helps a lot with feeling full as well.

How a calorie deficit can fail

The most common mistakes regarding calorie deficits are as follows: First off, without a calorie tracker, 99% of people underestimate their consumed calories and overestimate their burned calories. This means that people often round down their calories if they cannot track something easily like a condiment, so they just put in an arbitrary guess.

In the same vein people also add burned calories from exercise to the daily calorie estimate and this amount is often exaggerated – calorie trackers present in smart watches for instance tend to be somewhat inaccurate. I've noticed that disregarding your burned calories or only including half of the tracked amount into your diet calculations tends to keep your deficit functional: If your smart watch claims that you have burned 500 kcal running, you subtract 250 kcal from your daily average.

The second big challenge that stops most people is that calorie counting becomes too overwhelming, and I partly relate to this: I recently lost 12 kilograms over a very long time span as I wanted to focus on slow and steady weight loss, but I did not count my calories. I've counted calories for so long that I have a general grasp of how much energy my meals contain as I tend to eat the same things weekly, and on top of this I kept my portion sizes more modest than usual, but had I used calorie counting my process would probably have been much faster.

To anyone who feels overwhelmed with calorie counting, try to track your favorite meals and save them as "favorites" in your preferred calorie calculator app. That way you just choose your favorite meal without having to add in all the small individual ingredients, saving you a significant amount of time in the long run.

A really common reason why many fail is that despite doing a calorie deficit, they are not seeing results on the scale even on a weekly basis which demotivates them enough to quit. The reason why this happens can be due to many different things, but the easiest way to find out is by doing a little bit of analysis: Are you tracking every single food item? Are you perhaps ignoring ketchup, mayonnaise, or grated cheese on top of your meals or maybe you are not counting in liquid calories? A 16 fl oz bottle of regular Coca-Cola contains 210 kcal, and if you are on a modest deficit of 250 kcal per day, just one bottle of Coca-Cola reduces your daily deficit to 40 kcal, making your weekly weight loss negligible.

Another reason why you might not be seeing weekly progress is that your calorie target is simply misaligned. If you're absolutely sure that you include all your snacks and condiments and extras in your diet and you are still not losing weight, reduce your daily calorie target by 250 kcal. Online calorie calculators are inaccurate as they cannot account for genetics, stress, sleep and other factors that greatly influence your daily maintenance calorie level, so you have to go through some trial and error to find out!

Does exercise matter?

Regardless of if you are on a diet or not, exercise is crucial to feeling better and having more energy to get through the day. From a dieting perspective exercise makes dieting easier as the calorie burn allows you to eat slightly more per day to replenish that energy. You need to be very careful not to overestimate your spent calories and underestimate your consumed calories, so it is best to round down whatever calories your smart watch or phone app claim you have burned.

No matter how hard you exercise, you can never outrun a bad diet. While exercise is a great supplement to your diet, it cannot be the foundation for weight loss. Many mistakenly think that as long as they exercise for long enough they will be able to eat anything – this is false unless they are literally doing marathon-level amounts of exercise burning more than 1,000 kcal daily, and that is just not sustainable on a daily level, unless you are a professional athlete that can dedicate several hours to exercise every single day.

Briefly on some other weight loss methods

To put it simply, being in a calorie deficit and counting calories is the moderate and balanced way to lose weight, in my opinion. Even though many other diets and options exist and I fully encourage trying out different alternatives to find out what works for you, there is a certain compromise regarding calorie deficits that is unique: You don't necessarily need to cut back on any macronutrient group or restrict certain types of food or eating periods – all you need to worry about is not exceeding your daily calorie target – assuming you have it set up correctly. Even the most accurate calculators are approximate, so if you get a strangely low value from it, don't make any extreme changes to your diet. You can even eat your favorite foods and snacks every day as long as it doesn't bust your calorie budget.

The Ketogenic diet

As effective as calorie counting is, there are other diets that many find interesting and useful. One of these is the ketogenic diet (or "keto" for short), which is based on the function of ketogenesis: by eating a high-fat and low-carbohydrate diet, your body is forced to burn fats instead of carbohydrates. I think the keto diet has a lot of potential, as having to restrict and entire macronutrient group requires careful consideration regarding how and what to eat, promoting food awareness.

However, I think this is also the major weakness of the keto diet: Our digestive systems are by their nature designed to utilize all three macronutrient groups (carbs, proteins and fats) so completely leaving out or minimizing one macronutrient and maximizing another is always an extreme measure. I've noticed that I'm very dependent on carbohydrates as my primary source of energy for strength training, and I feel very nauseous if I have to work out with an inadequate amount of carbohydrates. The maximization of fat has adverse effects as well: As the modern health guidelines for fat intake indicate that the daily intake of fat should be no more than 30 % of your total daily calories, the keto diet puts you at risk of having high cholesterol, which is something many already struggle with due to their poor diet and nutrition.

If keto can work for you, that is great and I recommend you stick to it. However, if you feel it is causing you nausea and some common side effects, I warmly recommend trying a modest calorie deficit as a less extreme alternative instead.

The Atkins diet

The Atkins diet is a close relative of the Ketogenic diet, as it limits the carbohydrates to a minimum while keeping protein and fat "completely unlimited". The Atkins diet has been described as dangerous by several U.S. health associations due to the possible increased risk of heart disease and other problems. After the passing of Robert C. Atkins, the inventor of the diet and the author of the bestseller book, a medical report issued by the medical examiner's office stated that Atkins himself had a history of heart attack, congestive heart failure and hypertension. I am not a nutritionist or a doctor myself, but this supports my preliminary belief that extreme diets that restrict macronutrients are not good for you in the long run. As stated above with keto, you're free to try the Atkins diet as well, but a calorie deficit might offer a more modest and healthy approach.

How to retain the new lower weight

Assuming that you have reached your new goal, you're at a very important stage right now. You're like a mountain climber facing the last stretch to the top: You can succeed and reach the top with a last bit of patience or you can dash the straight, slip and fall off. If you just return to your old eating habits, you will gain most if not all of the weight back.

Even after a diet, you can still have the same favorite foods and snacks as you had before: You just need to have moderation. Some prefer to eat some of their favorite snack foods every day while others want to wait for the weekend and then have one day when they indulge in many of their favorites. There are plenty of ways how you can keep your preferences, but you can't return to your old habits expecting not to gain all the weight back.

A practical way to smooth off and end a calorie deficit is to eat more protein-dense foods, as a diet high in protein tends to help greatly with satiety. This satiety also reduces the chances that you'll indulge in foods with high fat content, so the chances of your weight staying low increase.

My absolute biggest gripe with diets is that they are an almost cyclical process: People want to shed weight at the start of the year for the summer in hopes of getting a "summer body", and then gradually returning to their old weight during the rest of the year. When you diet, you eat less food, and thus your body cannot maintain the body mass you had before. If you return to eating the same exact things and amounts after reaching your weight loss goal, you will return to your starting point, and you will be exactly as unhappy as before. This is why dieting should not be about a temporary change to improve your appearance, but a permanent improvement towards a healthier direction and lifestyle.

Habits that help weight loss

I covered this topic in a separate article quite recently and it contains a lot of valuable information – if you're interested in the topic, go check it out. The most effective daily habits that support your weight loss are eating a high protein diet and getting plenty of daily exercise with a consistency-focused approach. Explore the habits presented in the above article one at a time and you will maximize your chances of successfully implementing them. Don't get overwhelmed by trying too many things at once, but focus on the habits one at a time instead.


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