Do Calories Matter for Weight Loss?

Do calories matter for weight loss? Like most nutrition questions, there’s a simple answer…and one that’s a whole lot more complex.

The easy answer is “yes”. But, there’s MUCH more to it than that.

If you are trying to lose weight, gain weight, gain muscle, improve metabolism, yes, calories matter.

But, the type of calories ALSO matters.

Additionally, having too few calories ALSO matters.

And, our hormonal and metabolic health ALSO matters.

Okay, let’s start with type.

Simply put, calories = energy. Calories are something all foods have: lettuce, ice cream, apples, chicken, spaghetti, donuts, nuts, etc. They all have calories, albeit some more than ohers.

However, not all of these foods cause the body to respond in the same way.

For example, how full will we feel after a handful of potato chips? Not very, right? Alternatively, how full will we feel after a handful of nuts? Probably a little more full.

Some foods affect our satiety more-so than others. In the example above, if we just ate the chips, we are probably MORE likely to have additional calories than if we ate the almonds.

Nutrients that impact satiety?

  • Protein
  • Fiber/volume
  • Fats
  • Carbohydrates

Chips have carbs and fats, but lack protein and volume. They’ve also been processed. I like to think of this as “pre-digestion”. Anything that is processed outside the body, is easier for our bodies to break down, often making it less filling, or easy to consume more of.

Nuts have fat, a little protein, fiber, and they are a whole food. We have to chew nuts to break them down, and our stomachs have to work to finish digesting them, whereas chips dissolve in our mouth.

Calories from whole foods, though ALSO matter. Even though nuts are more filling, we can still overeat them and end up with too many calories. I see this often when I have clients trying to eat less carbohydrates. They will gravitate towards things with less carbs, like nuts, cheese, pepperoni…but all those foods are calorically dense and still impact our weight.

We CAN lose weight by solely tracking calories, even if the only thing we eat is twinkies. However, this would not only be very difficult because those calories add up quickly and wouldn’t be very filling, but it would also lack proper nutrition and we’d feel terrible.

Choosing mainly a variety of whole foods including carbohydrate-containing foods (vegetables, fruits, whole-grains, beans), proteins, and some healthy fats usually helps us obtain adequate nutrition and maintain a calorie deficit more easily.

In fact, if someone wants or needs to gain weight and/or muscle mass, or is pregnant and/or breastfeeding, it can actually be beneficial to consume some processed foods in order to eat enough calories. This has definitely been true for me. And by processed, I don’t necessarily mean junk food, but food that has been altered in some way. For example, smoothies: all those foods blended up are easier to eat than individually on thier own.

Now, let’s look at having too few calories.

If eating in a calorie surplus causes weight gain, then it makes sense that if we eat as few calories as possible then we will lose weight quickly, right?

Sure, this can happen to start. But, then things change.

Our bodies are not calculators. It’s not AS easy as “calories in, calories out.” We are complex systems with hormone regulation, gut microbiomes, and built-in safety mechanisms to keep us alive.

When we drop calories too low, this sends the signal to our bodies that there is less food available. Since our bodies’ main priority is to survive (not look good in a swimsuit), it will start conserving energy and down-regulate our metabolisms, meaning, we burn less calories.

The reason we consume calories is to fuel our body. Think about it like a fire, the more wood, the stronger and higher the flames; less wood, the lower and weaker the flames. No wood? No fire.

When the body senses insufficient energy, energy output decreases. We no longer have the oomf to get off the couch, let alone go to the gym. We aren’t even tapping our feet, we are so low on fuel. Our organ function decreases as well, and the body gives fuel only to the necessities: heart, lungs, etc. Even brain function can slow down. Although some might feel a bit more alert, this is the body being on the lookout for fuel sources.

So, basically, when we eat less and less calories, our body simply matches this in energy expenditure. Which takes a toll on our hormonal health and metabolism. Does the body feel that it’s a good time to conceive a baby if it thinks it’s starving? No. Does the body feel safe enough to relinquish excess body weight (a.k.a. stored fuel)? No.

Lastly: hormonal and metabolic health also matter

Calories are fuel, but if they are also coming along with the proper nutrients, our body will be firing from all cylinders.

There are 6 essential nutrients: water, carbs, fats, protein, vitamins, and minerals.

Those vitamins and minerals impact how our body functions in SO many ways, including the ability to take what we eat and turn it into energy. We may get enough total calories, but if the body is lacking in certain vitamins or minerals, this can manifest as cravings, causing us to seek out additional food (calories).

Inefficient carb consumption will affect the body negatively by down-regulating thyroid function, which impacts the function of nearly every other organ. Inefficient fat consumption prevents proper hormone development, which is needed for the body to function properly. Improper balance of fat types will increase inflammation, preventing weight loss. Inefficient protein intake decreases enzyme production, which we need to digest and assimilate food (as well as allow all other bodily functions to occur ) and causes muscle break down. The amount of muscle mass we have affects our metabolic rate. More muscle mass means we burn more calories at rest, less muscle mass, less calories at rest.

If these systems aren’t working properly, that can affect the body’s natural ability to utilize food. For example, our insulin/glucagon system is a hormone system. If there is inflammation present, or something contributing to insulin resistance, this prevents glucose from getting into the cell to be used as fuel, while keeping blood sugars high and insulin elevated. It also prevents glucagon, which takes fats from storage and turns it into glucose, from working because glucagon is used in the absense of insulin (usually between meals). In this situation, calories matter less because the difficulty with weight loss lies with the root cause affecting the proper function of the hormone system, not necessarily the calories themselves.


So do calories matter for weight loss? Again, yes, but there’s many other factors to consider than JUST caloric intake. All of this is just the surface. See what I mean about answers getting complex? We didn’t even talk about how stress, sleep, and hydration status affect calorie intake. SO MUCH affects our food choices, metabolism, and weight.

If you want to learn more, or work with someone to address your individual needs, head over to my coaching page!

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