Reasons Calories In, Calories Out is Just Wrong

We see calorie counts everywhere—on food packages, restaurant menus, and weight-loss diet programs. It seems like a fundamental truth: eat fewer calories than you burn, and you'll lose weight. But is it really that simple? Let’s explore what we actually know about calories and why the standard 2000 kcal/day guideline is not the golden rule many believe it to be.

What Are Calories?

A calorie (technically a kilocalorie) is a unit of energy. The term dates back to the 1800s when scientists first measured the amount of energy needed to heat 1 liter of water by 1 degree Celsius using a bomb calorimeter. In practical terms, we use calories to measure the energy in food and the energy our bodies need to function—everything from moving to keeping our hearts beating, thinking, breathing, digesting food, and regulating hormones.

But how do we determine how many calories we actually need?

How Calories Are Calculated

In the early 1800s, Wilbur Atwater developed a method to estimate how many calories we absorb from food. He used a bomb calorimeter to measure the calories in food, then measured how many calories were excreted in waste. The difference between these two numbers was considered the amount of energy we absorb. This method also led to the calorie counts we still use today:

• 4 kcal per gram of carbohydrate
• 4 kcal per gram of protein
• 9 kcal per gram of fat

However, this system oversimplifies how our bodies process food. It fails to account for:

• Digestion energy costs (10-15% of calorie intake, which varies by person)
• Genetic differences that affect metabolism and body shape
• Age, hormones, and medication effects on calorie usage
• Gut microbiota differences that influence how much energy we absorb from food

Calories are not an exact science—they vary widely from person to person and even day to day.

The Myth of "Eating Less = Losing Weight"

Many diet programs claim that reducing calorie intake by 500 kcal per day will lead to losing one pound per week. This idea originates from a 1959 study that estimated one pound of fat contains 3,500 kcal. The logic? Burn 3,500 kcal per week (500 kcal per day) and you’ll lose weight.

But the human body is far more complex:

• Your metabolism adapts—when you eat fewer calories, your body conserves energy and burns fewer calories just to maintain itself.
• Weight loss includes more than fat—initial weight loss comes from water and muscle, not just fat stores.
• Fat itself is metabolically active—losing fat changes hormone levels, further adjusting calorie needs.
• Dieting history affects metabolism—repeated dieting makes the body more efficient at detecting calorie reduction and adapting to it.

Simply put, eating less doesn’t guarantee ongoing weight loss. Instead, the body works to maintain stability, making calorie-counting an unreliable method for long-term health.

The 2000-Calorie Myth

We hear everywhere that the average person needs 2000 kcal per day, but where does this number come from?

• It was originally based on self-reported food intake data, ranging widely from 1600-3000 kcal/day. Self reported calorie intake is known to be under-reported.
• The U.S. FDA initially proposed 2350 kcal/day but lowered it to 2000 kcal to prevent potential "overconsumption," particularly among women.
• This number was never scientifically validated—it was chosen for convenience, not accuracy.

In reality, calorie needs vary drastically based on individual metabolism, activity level, and health status. Relying on a one-size-fits-all guideline is misleading.

Should We Count Calories?

Despite being widely promoted, calorie counting is inaccurate, impractical, and potentially harmful. Some risks include:

• Obsession—tracking calories can lead to stress and guilt around food.
• Malnutrition—focusing on calories can mean avoiding nutrient-dense foods that are higher in energy.
• Sense of failure—if calorie counting doesn’t lead to expected weight changes, it can negatively impact mental health.
• Disordered eating—fixation on calories can fuel unhealthy eating behaviors.
• Disconnection from hunger cues—calorie tracking overrides our natural ability to regulate food intake based on hunger and fullness signals.

Rather than controlling food through numbers, a better approach is to reconnect with your body's natural cues.

What to Do Instead

Instead of counting calories, focus on intuitive eating—listening to your body’s hunger, fullness, and satisfaction signals. Humans have been eating for thousands of years without calorie labels, and we are fully capable of regulating our intake without tracking numbers.

Some key shifts to consider:

• Trust your body's appetite signals—our bodies tell us when and how much to eat.
• Include a variety of foods—high-energy foods are not the enemy; they provide necessary nutrients.
• Rebuild a positive food relationship—food should be about nourishment, satisfaction, and social connection, not restriction.

If you've spent years dieting and tracking calories, reconnecting with your body might feel unfamiliar. But it is possible—and life-changing.

A Real-Life Example

One of my clients had spent years tracking every calorie but found that even extreme dieting no longer led to weight loss. By learning about metabolism and shifting her mindset, she stopped calorie counting and started listening to her hunger and fullness cues. She rediscovered the joy of food, reduced stress around eating, and improved her overall well-being—without the constant fear of "eating too much."

Want to Start Feeling Better Around Food Today?

If you feel stuck counting calories and stressing over every bite, the solution is not another diet—it’s changing your relationship with food.

That’s why I’ve created a free e-book: "Stop Stressing Over Food—The 5 Steps You Need for Joyful Eating." This guide will help you break free from calorie obsession and build a healthier, more peaceful connection with food.

📩 Download your free copy now.

Or, if you’re ready for personalised support, book a free discovery call to learn how I can help you feel good in your body and around food.

👉Book a free call here.

Final Thoughts

Calorie counting has been normalized, but it’s not scientifically sound—and it can do more harm than good. If tracking calories feels stressful or controlling, know that there’s a better way to approach food and health.

If you found this helpful: 

✅ Listen to the Food & Life Freedom Podcast
✅ Share this post with someone who will find it helpful.
✅ Check out the free and paid courses and resources I offer.

You deserve a peaceful relationship with food. Let’s start today!