Since I got my first iPhone in 2011, I’ve been an avid user of calorie-tracking apps. So much so that I didn’t even notice this obscure streak until around day 90. It’s just part of my routine.

I realize this makes me an odd duck. Logging food is a chore for most people, and doing it every day sounds tortuously tedious.

That’s why I’m sharing what I learned from obsessively counting calories — so you don’t have to. You can apply these insights to your diet, even if you never count a single calorie.

I will also reveal the downsides of tracking calories and what I do now to allow more flexibility in my fitness routine.

Why I Started Counting Calories

Earlier this year, I set out to lose the unappealing fat in my midsection. But this wasn’t a typical crash diet to lose 10 or 15 pounds for beach season.

While counting calories works well for more aggressive weight loss, I focused on a slow and steady approach.

Here’s the “why” and the “how” of my calorie counting process.

A Specific Fitness Goal

My goal was to burn fat without starving myself or losing muscle, even if it took six months instead of six weeks.

That’s still a relatively vague target. A better goal is specific and measurable according to the SMART framework.

In my case, I aimed for gradual weight loss of 1/2 a pound per week, and I wanted all of that weight to be body fat.

A Precise Calorie Target

A goal is only as valuable as the plan to achieve it. So, the next step was establishing a calorie target that would result in my desired rate of fat loss.

To reverse engineer my goal, I started with the assumption that one pound of fat is equivalent to 3,500 calories. And a 500-calorie deficit results in one pound per week of fat loss (3,500 / 7 = 500).

By this logic, a daily deficit of 250 calories should result in half a pound of weight loss per week. It’s an oversimplification of metabolic dynamics but a decent starting point.

A Feedback Loop for Improvement

Targeting a calorie deficit of 250 calories is possible, although it requires aircraft-grade precision in your diet.

To pull it off, I needed to know my total daily energy expenditure or TDEE. Plugging my height, weight, and age into a generic TDEE calculator wouldn’t cut it.

So, I also tracked my daily calories burned using an Oura ring for everyday activity and an Apple watch for workouts.

Measuring both energy inputs and outputs allowed me to adjust my calorie intake in real time based on my actual activity level. For example:

• On an intense leg day where I burned 3,300 calories, I could eat 3,050 calories and hit my 250-calorie deficit target.
• On a laid-back rest day where I only burned 2,600 calories, I had a calorie intake budget of 2,350 calories.

In addition, I recorded my weight and body fat percentage at least a few times a week. Then, I adjusted my calorie intake if necessary to ensure continuous improvement.

Your results will look different if you have a significant amount of body fat to lose, and you may need to use a more aggressive calorie deficit to get the results you want.

Different situations and goals require different strategies and targets. However, calorie counting can work for almost anyone if applied correctly.

I don’t expect you to be this rigid in your diet. Heck, I wasn’t even expecting that level of consistency from myself!

Instead, I consider it a personal experiment — a case study with hundreds of data points and months of hands-on experience.

My job is to sift through the results and compile the information into practical tips for your daily diet routine. Here are my key findings.

1. Focus On What Matters Most

From meticulously tracking my food intake, I’ve learned that calories are the most significant factor in weight management.

a. The Physics of Energy Balance:

I remember from Thermodynamics that you cannot create or destroy energy; you can only convert it to something else. So, it’s unsurprising that energy balance is the basis of losing or gaining body mass.

To put it another way, consider your checking account’s daily deposits and withdrawals. The monthly bank statement reflects your net balance, not whether you deposit cash or checks.

Similarly, your body weight depends more on the number of calories you consume than on the ratio of carbs and fat.

b. Counting Macros vs Calories:

Many mainstream diets focus on macronutrients — such as Keto or If It Fits Your Macros (IIFYM). There’s nothing wrong with that approach if it works for you.

However, calories are often pulling the strings behind the macro curtain.

• Keto involves reducing carb intake and benefits glucose levels and insulin sensitivity, especially if you’re overweight. Cutting carbs also typically creates a calorie deficit, the primary driver of weight loss.
• IIFYM involves counting grams of carbs, protein, and fat. The thing is, each gram of these macronutrients has a designated number of calories (4 for carbs, 4 for protein, 9 for fat). Therefore, by counting macros, you’re also counting calories!

You can reach your goals as long as your macro targets align with the proper energy balance.

To prove this for myself, I ate an average of nearly 400 grams of carbohydrates daily (50–60% of calories) during this calorie-counting experiment. Even on a high-carb diet, I still lost body mass at the predicted rate because I maintained a calorie deficit.