There’s More to Weight-Loss Than the 3500 Calorie Rule

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Have you heard of the “3500 calorie rule? If you haven’t heard of it, I’d be surprised.⁣

This *rule* was born out of the fact that 1lb of fat stores 3500 calories,⁣

Following that rule, in order to lose 1lb of fat per week, you need to eat 3500 calories less per week.⁣ That’s 500 calories less per day.

Things aren’t quite that simple. If they were, I wouldn’t have a job, and you wouldn’t be reading this blog. 

What the research says

We looked at seven different weight-loss studies, and here’s what we found: 

First off, researchers suggest that we use a more dynamic model to determine weight-loss requirements. This model includes additional factors such as:

  • Baseline body composition
  • Age
  • Height
  • Gender
  • Degree of caloric restriction

A dynamic model that considers individual factors is a much better predictor of weight-loss trajectory. 

The “3500 calorie rule” is an oversimplification of weight loss. For the same reason that coaches are better than calculators, the “3500 calorie rule” doesn’t know all the personal factors that influence your weight loss.

More considerations 

 If the study above doesn’t convince you, here are a few more reasons why things are more complicated than simple math:⁣

When you lose weight, you typically aren’t ONLY losing fat. ⁣

What that weight loss is made up of (e.g., fat, muscle, water, etc.) is determined by other factors such as exercise (frequency, duration, type), protein intake, and hormonal health (e.g., testosterone, thyroid, cortisol), to name just a few!⁣

Metabolic adaption⁣

 In the simplest terms, even if you were to find a true deficit of 500 calories on week 1 of a diet, eventually your body will adapt, and that 500 calorie deficit (and related weight loss) will no longer produce the same effects over time.⁣

Metabolic adaptation is why you plateau and typically need to increase the deficit as your diet progresses.⁣

Individuals are individual⁣

The 3500 calorie rule assumes that every person (regardless of stats or current calorie intake) should decrease their daily consumption by 500 calories per day.⁣

With that logic, a man eating 3500 calories per day would reduce his caloric intake to 3000 calories daily (a 14% percent decrease). A woman eating 2000 calories per day would reduce her intake to 1500 calories per day (a 25% decrease). That’s over a 10% difference in reduction when applying this rule to two people. ⁣


You might not even need such a steep deficit to kick off your dieting pursuits.⁣

A 500 calorie reduction is a lot.

You could probably eat more calories while still seeing progress.⁣

At KJO Coaching, we have our own rule:⁣

Eat as much as possible while still working towards your goals.⁣

And, of course, build a stronger body and mind along the way.