What’s the Best Measure of Food? Calories vs Other Properties


Thanks to our modern food environment, we have over-complicated food to the point of creating mass confusion over how to eat.  Our ancestors (from Australopithecus to just a couple generations ago) didn’t have nutrition labels on their food and certainly didn’t pay any attention to calories, macros, or any other factoid about the food they were eating.  They ate from the land.  They ate real food.  They ate to survive and to fuel their bodies to perform their daily activities.  They listened to their bodies and ate when they needed to eat.

Enter the Calorie

The calorie has been the dominant measure of food for several decades, but is not necessarily the most useful.  The 1st use of the term ‘calorie’ in regards to food was in the late 1800’s.  Recognizing that calories were an oversimplification of nutrition, physicians in the 1910’s were skeptical of granting the calorie “an unwise domination” in the selection of food, noting that “wise buying of food must sometimes look beyond the energy measure”.   Calories were better suited for application to large populations (cities, armies, etc.) rather than guiding individual eating habits.

Calories In Calories Out

Today, there is great debate about calories in the nutrition world, and that will surely never end.  Many pundits insist that calories are the only answer when it comes to body weight, referencing the Law of Conservation of Energy.  They often use the analogy that calories are to body weight what dollars are to your bank account balance.  Unfortunately, this Calories In Calories Out (CICO) model is over-simplified and doesn’t reflect the complexity of the human body.

Fitness fanatics live and die by the Calories In Calories Out model, endlessly disputing claims that any other strategies might have merit.  Perhaps there’s more to it, though.

Atwater, W.O. The Potential Energy of Food. The Chemistry and Economy of Food. III. Century 1887; 34:397-405.

More than just weight loss

The firm believers in Calories In Calories Out (CICO) may argue that there are no tangible differences in body weight when calories are matched and that weight loss can only occur in the setting of a calorie deficit.  That may be true in the short-term, based on some research studies.  However, there are other qualities of food that are perhaps more important to consider than calories alone.  These other qualities are just not as readily apparent as are changes in body weight or size.

Does anyone really believe that 1000 calories of salmon is equivalent to 1000 calories of table sugar?  Obviously, a diet consisting solely of table sugar is unrealistic and is [hopefully] not at all a consideration.  The point of this question, however, is that everything in the nutrition world exists on a continuum – if you must, consider the aforementioned salmon pitted against a diet consisting of 1000 calories of pasta, soda, and ice cream.  At what point does it get ridiculous?

The rest of the story

The calorie was never intended to be a measure of the health value of food, and yet that’s exactly how it’s come to be considered.  A simple measure of heat production from burning a food item can’t possibly capture what’s happening biochemically within the body in response to vastly different food sources.

The food we eat has many effects on the body, and thus it doesn’t make sense to focus on only one.  Other qualities that are more important to consider include:

  • Nutrient density – the concentration of micronutrients: vitamins, minerals, and other factors such as phytochemicals or zoochemicals
  • Hormonal effect – how food affects hormone systems such as insulin, estrogen, cortisol, and thyroid hormones
  • Satiety factor – whether a food causes a sense of fullness or leaves one wanting more to eat


Next: Let’s look beyond the over-simplified calorie and explore these other qualities in more detail.

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