Yesterday afternoon I was sitting in the waiting room, waiting (obviously) for my appointment time, when I couldn’t help but overhear two women having a discussion about calories.

“How many calories are in that?” one woman asked the other in reference to a snack bag of chips.

“One-fifty” the other replied.

“Oh, this one has more.”

It was a brief, well-intentioned discussion really. But it made me sad. It always makes me sad to hear people discuss calories and miss the entire point of whether or not their food choices will actually serve them.

Because really, calories tell us almost nothing about the food we are eating. A calorie is, quite simply, a measurement of the energy required to raise the temperature of 1 gram of water by 1 degree celsius.

I repeat, calories are energy.

In his article, “Why Calories Don’t Matter,” Dr. Mark Hyman writes:

Newton’s first law of thermodynamics states that the energy of an isolated system is constant. In other words, in a laboratory, or “isolated system,” 1,000 calories of broccoli and 1,000 calories of soda are, in fact, the same. I’m not saying Newton was wrong about that. It’s true that when burned in a laboratory setting, 1,000 calories of broccoli and 1,000 calories of soda would indeed release the same amount of energy.


But sorry, Mr. Newton; your law of thermodynamics doesn’t apply in living, breathing, digesting systems. When you eat food, the “isolated system” part of the equation goes out the window. The food interacts with your biology, a complex adaptive system that instantly transforms every bite.

Given the complexity of our biology and the physiological processes that occur within our bodies in response to nutrient intake, when we only look at the calorie content of food, we are missing an enormous piece (like 99% actually) of the equation.

For instance, calories will not tell us:

The macro and micro nutrient content of our food.

How many grams of fat, protein, and carbohydrates are in this food? Is it a good source of vitamins, minerals, and phytonutrients?

How the food will raise our blood sugar.

Is this food high in carbohydrates and low in fiber, fat, and protein? Or, in other words, do I know where this food falls on the glycemic index?

How our individual bodies will react to the food.

Will my body properly digest this food, or do I perhaps have an intolerance that will cause issues (for instance, to gluten, lactose, or fructose)? Am I at all allergic to this food?

How the food was grown or raised.

Was this food grown or raised organically? If it is from an animal, how was the animal treated, what was the animal fed, and how was the animal killed? Has this food been treated with chemical pesticides, antibiotics or hormones? (See this list for pesticides and hormones to look out for).

Chemicals or additives used in the food.

Similar to the previous point, what sorts of chemicals have been used in the processing of this food? Artificial food coloring, preservatives? (Check out this list of food additives to avoid).

How much we will enjoy the food.

Yes, this is highly individualized and will also depend on the day, our surroundings, and our mood. But nonetheless, it’s important to consider, how good will this food taste to me in this moment? How satisfying will it be? Will this food give me energy, or make me sluggish?

Merely glancing at a calorie label will not tell us any of this information. And yet, all of this information is crucial to how the food affects our health.

A couple of tweetables for you:

[bctt tweet=”You are what you eat eats. -Michael Pollan”]

[bctt tweet=”Calories leave out 99% of the critical information we need to know about our food.”]