Am I Losing a Pound of Fat When I Burn 3500 Calories?

The Science Behind The Burn

We are familiar with the famous theory that burning 3500 calories means we lose a pound of fat. Although there may be some truth to this hypothesis, fat isn’t the only thing lost when we burn calories. Recent studies have examined the 3500 calorie concept and what’s really lost in the process.

How the Theory Started

Slow progress is better than no progress
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The 3500 calorie deficit formula was born of science years ago. Original research examining fat burning and calories was conducted by Max Wishnofsky M.D in 1958. He published the 3500 calorie deficit formula which continues to be cited in thousands of educational websites, studies, and scientific articles.

Dr.  Kevin Hall challenged the formula and released a manuscript in 2007. His work redefined the 3500 calories to burn a pound idea. His paper was impressive and included reliable scientific data and formulas to question the outdated research. His discovery prompted further studies on the old theory. 

Further research was conducted by Dr. D.M. Thomas and published in The International Journal of Obesity. His research not only debunked the 3500 calories to burn a pound theory, but also provided three reliable downloadable applications calculating models of weight change. Those links are provided at the end of this article.

Understanding the 3500 Calorie Deficit

Losing fat can be a challenge. We have been under the impression simply subtracting 3500 calories per week, we would be able to lose one pound of flab. This is based on the old theory where 3500 calories represent only fat and not taking into consideration lean mass (muscle).

Research has moved beyond that old theory. The updated concept takes all body tissue into account understanding muscle is also lost during the calorie burning process. The amount of muscle lost depends on initial body fat level and caloric deficit. This updated information has provided a more accurate breakdown of what happens when we burn calories. 

This means burning 3500 calories no longer fits under a general umbrella for losing fat. In fact, the weight and fat loss calculation will differ from person to person. For example, a lean person will tend to lose more muscle and retain fat while an overweight person will lose more body fat and retain lean mass.

This is why an overweight person can better tolerate lower calorie diets and the opposite applies to a lean person. However, restrictive diets are not recommended for either since they are indicated to cause muscle loss. Our goal with weight loss is being able to lose fat while gaining or maintaining muscle.

How Are Fat and Muscle Metabolized?

The original 3500 calories to burn a pound theory failed to take into consideration the difference between fat and muscle tissue. Muscle is highly anabolic using calories at a much higher rate than fat. The updated theory examines how fat and muscle tissue metabolize (use) energy at different rates.

A pound of muscle is not 3500 calories but approximately 600 calories. If you applied a 3500 weekly caloric deficit and lost 100% muscle hypothetically that would equate to 6lbs. This of course would be impossible since fat is also lost in the process. The point is to understand lean mass loss equals greater weight loss. Decreasing lean mass is what we're trying to avoid.
 
If you created a 3500 caloric deficit and lost 100% body fat, then you would lose one pound of fat. Again, this is impossible because both lean and fat tissue is lost when we lose weight. 

The new theory also takes into consideration the need for caloric deficit adjustments as body weight decreases and energy levels decline. Also recommended is stimulating more fat loss and maintaining lean mass through progressive resistance training and higher protein intake.  

Can I Still Use the Old Formula?

Does this mean the old 3500 calories to burn a pound formula is unreliable and shouldn’t be used? The answer is – no.

Lots of great research went into creating a basic way to figure out daily caloric requirements. Using the 500 to 1000 calorie per day deficit does provide a general guideline for losing one to two pounds per week. 

The studies just wanted to clarify the inaccuracy of the 3500 caloric deficit theory burning only fat tissue. The update provides a proper explanation of caloric deficit requirements.

The new weight loss applications are also a fun way to discover what works best for you:

The first link is for individuals who want to see weight loss/gain estimates in response to changes in dietary intake:

SINGLE SUBJECT WEIGHT CHANGE PREDICTOR

The second link is for group weight loss scenarios designed to inform about weight change through experimental design and analysis:

MULTI-SUBJECT WEIGHT CHANGE PREDICTOR

Sources:
D M Thomas et al., Can a weight loss of one pound a week be achieved with a 3500-kcal deficit, International Journal of Obesity, 2013

Forbes GB, Body fat content influences the body composition response to nutrition and exercise, Annals of the New Your Academy of Sciences, 2000

Kevin D. Hall, What is the Required Energy Deficit per unit Weight Loss, International Journal of Obesity, 2007

Kevin D. Hall, Body Fat and Fat-Free Mass Interrelationships, Forbes’s Theory Revisited, British Journal of Nutrition, 2007

Max Wishnofsky, M.D., Caloric Equivalents of Gained or Lost Weight, The American Journal of Clinical Nutrition, 1958

 

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