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  • Brian Bender, PhD

Does Calorie Counting Work? Your Complete Guide

Counting calories typically takes a lot of time and effort. You have to search and find your foods in an app, estimate the quantity you’ve eaten, or worse, spend time filling old fashioned, pen and paper notebooks tracking your calories and macronutrients.

Plus, you need to spend brain space on thinking about what you’re eating all day, remembering it, or interrupting your days consistently to track each morsel.

Is it worth it?

Calorie counting is a controversial topic in the world of diet and nutrition.

For some, in invokes praise. Many studies in the academic literature show that calorie counting works for weight loss. In fact, quite consistently.

For others, calorie counting is the manifestation of all that is bad with diet culture. It separates your food into a numbers game and for some, may trigger a new host of mental ailments to tackle.

So who’s right?

As is often the case with nutrition, both can be right. And both can be wrong.

The guide will discuss the good, the bad, and the ugly about calorie counting.

We’ll go into the pros, and why some say calorie counting can be a useful tool for meeting your weight goals and what are the best ways to go about it.

And we’ll also dive into the not so good. What’s wrong with calorie counting, why can calorie counting fail, and the controversy surrounding the practice.

Note: this guide is not intended to be medical advice. Please consult your doctor before changing healthcare practices.

Nearly 3 Decades of Research Show Calorie Counting Works for Weight Loss


Peer-reviewed, scientific literature shows that calorie counting helps individuals consistently lose weight. And a plethora of research articles published in the last 5 years using new technologies to assist this effort show similar, positive results.

Now, before you get too excited (or angry), let’s take a look at some of the caveats.

First, the studies in these review are not randomized controlled trials.

Why does that matter?

RCTs are the gold standard of medical research. Without having a long, historical list of RCTs to back up these claims, we are left with imperfect conclusions.

So, studies certainly look like calorie counting works, and the results are consistent, but we can’t be 100% sure.

Why might calorie counting work for weight loss?

A few possibilities.

First, calorie counting helps you get an idea of how much food you are actually eating through the day.

Studies have investigated our ability to estimate in our heads how many calories we eat.

You may or may not be surprised to hear - we aren’t that good at it.

In fact, we can sometimes be off by 90%!

Most of us generally don’t investigate calorie content. If we’re preparing food at home, eating a dish prepared by friend or family, or even eating at a restaurant, we typically don’t know the caloric content of our meals.

And unless we diligently check the contents of our packaged foods (and don’t forget to account for the serving size), we often fail to realize the calorie density of the foods (and drinks!) we consume regularly.

Second, calorie counting can help you understand the breakdown of the food you are eating.

If you thought estimating calories was tough, try estimating the sugar content of your foods! And just like estimating calories, studies show we do a poor job of this as well.

And it shows.

The World Health Organization recommends we consume less than 10% of our calories from sugar, for example. They go further and say reducing your caloric intake of sugar to 5% of calories is even better.

6% of our calories? 12%?

More like a whopping 18%! Over 95% of Americans - just about every one of us - exceeds the 10% WHO recommendation.

Third, calorie counting can be a stepping stone towards intuitive eating.

Intuitive eating is the skill of having an innate, underlying understanding of healthy eating habits and mindful eating.

Through calorie counting, many individuals must take notice of the foods they eat throughout the day.

Often, we eat without thinking about it.

Munching on popcorn during a movie. Snacking at the office. Eating a burrito in the car on your way home?

But bringing these meals into your consciousness - your prefrontal cortex - can shift your mindset. It can help you take stock of the food you eat, build mindful eating habits, and gradually become a more intuitive eater.

For some, this practice may persist. They may be able to quit calorie counting and still take stock of the foods they eat throughout the day.

Others may gradually lose the skill again over time.

Things brings us back to central theme of this article.

Not all tools and practices work for everyone.

But for some, they can be extremely valuable. Even, life-changing.

So why is it bad for some?

An Obsession with Calorie Counting can Lead to Eating Disorders

For some folks, calorie counting can become an unhealthy practice.

Just like habitually stepping on a scale and can lead many to shed pounds, it can also lead many to feel shame, anxiety, and depression.

The end-goal of any weight loss program is to reach a steady, healthy weight. And the key to any healthy diet, is to establish a nutritious, balanced diet that you maintain throughout your life.

But calorie counting can become obsessive and even counter-productive.

Some may find the anxiety associated with keeping track of every meal and every bite overwhelming. To the point of even causing weight gain and unhealthy eating practices.

On the other end of the spectrum, it can lead to eating disorders that lead to chronic undernutrition, such as anorexia or bulimia.

Others may maintain a healthy weight and even a balanced, nutritious diet, but suffer from a condition known as orthorexia. This condition, arguably growing in numbers, is the condition of being overly consumed with the idea of eating the most nutritious foods, all of the time. To the point of causing mental anguish and anxiety around the act of eating.

Obesity and poorly balanced nutrition are some of the leading disease risk factors we face as a people. But replacing them at the expense of mental anguish is hardly a win.

Thus, calorie counting can be a misguided strategy for some. If you find yourself creating an unhealthy relationship with food or body image while calorie counting, it would be wise to seek help from qualified individuals.

Beyond mental health concerns, calorie counting can also result in poor outcomes simply because calorie counting is hard.

Not hard because math is hard.

Well…it’s kinda hard.

But even if you aced your algebra, there are many issues with calorie counting that will lead you to erroneous numbers.

Meat and vegetable products have variable nutrient content

You are what you eat.

This isn’t a phrase that only applies to people. It applies to all animals.

And relevant to calorie counting, this applies to the livestock we consume. The conditions with which livestock are raised affects the nutrient profiles of their fat and muscle tissue.

Therefore, when an online database provides a number of calories or protein per gram of chicken, that number could vary depending on how that chicken was raised and what it was fed.

This even applies to plants.

The fruit and vegetable trees grow in different soil compositions and are exposed to different amounts of sunshine, water, and temperatures.

This variety of growing conditions throughout the world creates produce with varying nutrient profiles.

Cooking foods changes the nutrient content

The process of food preparation changes the nutrient content of the foods we eat, thus making calorie counting difficult to predict as well.

Adding heat - of varying temperature and duration - can catalyze chemical reactions involving the nutritional content of your food. Thus, some molecules may break apart, becoming more digestible. Others may bind to each and form less digestible molecules.

Even the act of slicing, dicing, and smashing foods can change the degree of digestibility, and thus, the nutrient profile of the foods you eat.

For example, 100 grams of raw broccoli has about 34 calories, 2.82 grams of protein, 0.37 grams of fat, 6.64 grams of carbohydrates, and 2.6 grams of fiber. However, boiled broccoli decreases protein content by 16%, while increasing calories by 3%, fats by 11%, total carbohydrates by 8%, and fiber by 27%.

Eggs are another example; 100 grams of raw egg comes in at 143 calories. But a hard-boiled egg has over 8% more calories, 11.5% more fat, and 202% more sugars.

And cooking in water or oils can cause different macromolecules, vitamins, and minerals to leach out.

Nutrition labels

When you are calorie counting on your own, or even if you use an app, the data typically comes from the nutrition label or online databases. But are those accurate?

The FDA allows up to 20% error on its labeled nutrition quantities for calories, macronutrients, and micronutrients for natural foods. Those errors can seriously add up.

And even though the nutrition labels on processed and fortified foods are supposed to contain 100% of the nutrients they claim, studies have shown error of 8% on packaged foods.

Restaurants may be the worst on nutrient content claims. Some studies have shown a difference in content of 96% on some restaurant menus.

We absorb calories differently

Let’s face the obvious here. Our bodies don’t all behave the same way.

One of the ways they are different that affects our calorie counting efforts is the way our bodies absorb food and their nutrients.

One way this works is in your gut.

Your gut microbiome is unique to you. It is heavily influenced by environmental factors, like diet, exercise, stress, and other factors.

Scientists are discovering the bacteria inside of your gut affect a range of health issues. And there is an interesting symbiosis that exists with these bacteria and your diet. Your diet affects your gut microbiome, and your gut microbiome affects your diet.

Fiber is a case in point.

Our bodies cannot naturally digest fiber. Therefore, we shouldn’t be able to extract calories from the fiber we eat.

Yet, most of us still do, thanks to the bacteria inside of our intestines.

So depending on the diversity of bacteria present, we may be obtaining more or less calories from the fiber we eat.

Other, more subtle differences affect the nutrients we absorb as well. For example, some people experience more or less inflammation from different foods. This inflammation can subsequently decrease nutrient absorption when these individuals eat these foods.

Our genes and our environments help shape who we are and how we lives. And together, this shapes the subtleties of digestion.

We use calories differently

Calorie counting usually is done to estimate what you are consuming as well as what you are expending. And while this discussion is focused on counting calories that go in, it’s worth mentioning the variability of calories going out.

Metabolism dictates our body’s caloric needs. And while much of our metabolism is dictated by our body composition and age, some natural variability along with very different levels of daily activity means tracking calories out can be difficult. This is why most trackers of calorie expenditure have large errors associated with them.

Accessing real, physiological dietary intake data

The solution for accurate data? Go to the source!

If it is too difficult to accurately assess what is going in, it becomes easier, and more accurate, to assess what’s going out.

How does that work?

Digestion and metabolism are your body’s processes for extracting energy and nutrients from the food we consume.

The food and its nutrient content goes in through the mouth, gets digested in the stomach and your intestines. Some of the nutrients get absorb and used through the body. And others get excreted through…well…we all have bathrooms for a reason.

But our bodies are pretty good at keep us healthy…most of the time. It does this through various homeostatic mechanisms.

This means, our bodies help regulate our internal processes to keep things as close to even levels as possible.

If we eat too much of something, we typically excrete more of it to keep us in balance. If we eat too little of something, we excrete less to make sure our bodies have enough.

So the end products of digestion (for example, urine), are actually very complex solutions full of different molecules and proteins that are constantly changing in concentration.

And your body is always on. It doesn’t forget a meal, and it doesn’t have to spend energy calorie counting.

It just keeps your body humming, and altering internal absorption, metabolism, filtration, and excretion.

So why not just measure that and call it a day!

For those of you looking to find success meeting your dietary targets for weight loss, preventative healthcare, or athletic performance, the easiest way is to measure your physiological intake data.

Intake’s mission is to improve global health through data-driven nutrition. Our blog provides information, education, tools, and tips about all things related to nutrition, including healthy eating, disease prevention, peak performance, and personalization. Sign up for alerts on new posts and product updates!


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