A Calorie is a Calorie

Obesity is the source of many problems we face as a country today. It is an expensive condition, placing a huge burden on our healthcare system. It is also deadly, contributing to a myriad of further health complications including diabetes, hypertension, and heart failure. It causes a huge amount of suffering for the individual, but also takes its toll societally placing major strain on the country as a whole. More than half of America is overweight and 2 in 5 people are classified as obese. This is a relatively recent problem that has been getting worse over the last half century and as a country we appear to be inept at trying to solve it. 

So what is causing so many people to become overweight and obese? I’ve heard “reputable” people say it’s genetics, presumably as a way to take responsibility away from the individual. However, if genetics is to blame, why were people not obese 80 years ago? Did our genetics change? And why is America, the most genetically diverse country on the planet, suffering the most? People also like to blame individual foods whether it's meat, dairy, GLUTEN, or spooky compounds like lectins. These supposed causes of obesity are also ridiculous and are meant to develop products and books to sell you. You have probably also heard that insulin is the reason we are all overweight because it “prevents fat burning.” This is also ludicrous and I will explain why. In general, if somebody on the internet tells you there is one reason why you are overweight, do not believe them. 

So what is the cause of obesity if it’s none of these things? What most people don’t want to hear is that when it comes down to it, obesity is caused by eating more calories than you burn, plain and simple. While tracking the calories you take in is relatively straightforward (albeit very inaccurate), many things contribute to calorie burn. These include the ones we always think about such as exercise and daily activity, but we also have to take into account the thousands of chemical reactions and hormonal signals taking place in our bodies and how we influence these with our behavior.

When someone starts on a journey to lose fat and get healthier a lot of the time they are searching for the “secret” to fat loss, generally as a way to make it easier. We are a culture of hacks and shortcuts so why approach it any other way? Losing weight and changing your body is very difficult so I don’t blame anyone for trying to make it a bit more manageable. However, the problem here is that obesity is way more complex than most people perceive it to be, and you cannot take a millenial’s “I’m just gonna write a code to make me skinny” approach. We don’t live in the metaverse yet so it’s still worth caring about what you look and feel like in this reality. 

So if weight loss is as simple as calories in/calories out why are so many people unable to lose weight even though they think they are in a caloric deficit? I’ve heard this one countless times and I cringe each time somebody says it. The reason they are not losing weight is because they are not in a caloric deficit. 

To fully grasp why it’s impossible to gain or maintain body weight (assuming you are not retaining water) while in a deficit we need to first understand one key point. This point is super controversial for some reason and I don’t know why because it’s blatantly obvious. A calorie is a calorie. A calorie is a way to measure heat. It is a quantitative unit that cannot be changed. It’s like measuring temperature using a thermometer, a degree is a degree no matter what anybody says. If your body is burning more calories than it's taking in you will lose weight according to the laws of thermodynamics. However, while all calories are equal, all sources of calories are not. As I said previously a calorie is a calorie because it is a unit of heat in its simplest form. However, where we get these calories from is extremely important, because the sources of calories vary greatly in how they interact with our body.

Calories In

As I said before, weight loss at its essence really is as simple as calories in/calories out. Your body cannot create nor destroy matter, so conservation of energy needs to be followed. The calories in portion of this equation is relatively simple, it consists of the food you eat. If you want to lower the calories you take in, eat less calories. While this part of the equation is easier to comprehend than the calories out piece, I should note it is nearly impossible to accurately quantify how many calories you are actually ingesting. If you track calories you will always be wrong to some extent, however, I do recommend tracking consistently simply to see where your average range is. Studies show that the average person underestimates their caloric intake by as much as 50%. You wouldn’t believe how many times I have heard, “But Mark, I have only been eating ____ calories per day and I still haven’t lost weight!” My first thought is that this is most likely an inaccurate representation and I need to add at least 25% to that number.

Calories Out

So if the calories in portion of the weight equation comes down to the food you eat, what determines calories out? Calories out is extremely complex and impossible to measure accurately with the devices we wear. Calories out is the sum total of four different categories:

-Exercise- Intentional movement to elicit heart or muscular response.

-Non-exercise activity thermogenesis (N.E.A.T)- Calories burned through daily living such as standing up and taking out the garbage.

-Thermic effect of food (T.E.F)- The energy used in order to digest food you eat.

-Basal metabolic rate (BMR)- The sum total of all metabolic processes in your body if you just laid in bed and did absolutely nothing (heart beat, nerve activity, etc.) This is what we refer to as one’s metabolism. 

As you can see exercise plays a surprisingly small role in the total calories an average individual burns on a daily basis. This is why I always emphasize to clients that when we exercise the goal is not to burn calories. Because the calories we burn during exercise are realistically inconsequential compared to what we eat and what we burn in other areas of our life. Remember when I mentioned people tend to underestimate their food intake by 25-50%? Well on the other hand they also tend to overestimate their exercise calorie burn by 50-100%!

Let’s look at this mathematically with a hypothetical person named Emily. Emily comes to me with a log showing that she is burning around 2000 calories per day (400 through exercise) and eating 1500 putting her into a 500 calorie deficit daily. She would expect to lose about a pound per week at this deficit but unfortunately she finds herself not losing any weight. She was on the verge of giving up, throwing up her hands and saying she simply cannot lose weight and her hormones are causing this issue. This is a very common situation I see with clients and I think many of you can relate. If Emily has been tracking her numbers like most people her caloric intake is underestimated by at least 25% and her caloric burn is overestimated by at least 50%. These would put her real numbers at around 1875 eaten per day and 1900 burned. Now you can see how somebody can struggle to lose weight while eating in a “deficit”!

So if tracking is so inaccurate why do we do it? We track to analyze trends over time and to hold ourselves accountable with exercise and nutrition. While tracking is not accurate, if it is consistent and precise enough we will see approximately how much you are eating and burning and if we have to adjust those numbers. The numbers are all relative for each individual, and they are the only way we can really see how your lifestyle is affecting your weight gain or loss.

Why some calorie sources are better than others

So if a calorie is a calorie why can’t I eat junk food if I control my calories? Well, you can. But it makes everything way harder. Remember, all sources of calories are not created equal. There are many reasons why 100 calories of broccoli is better than 100 calories of candy. Here are some of the reasons why eating healthier food is important:

-Vitamins and minerals in the healthier food will help your body function and feel better.

-Water will help you feel fuller longer.

-Fiber will help you feel full and has a high thermic effect of food (Remember this?)

-Healthier foods contain more protein which also helps you feel full and has a super high TEF.

The key point here when it comes to calories in/calories out is that when you eat healthier food you will have a higher TEF after each meal. What this means is that if you eat the exact same calories in junk food versus high protein/fiber foods you will actually burn more calories when you eat the healthy stuff. This point is extremely important and accounts for a lot of the discrepancy in the calories out equation that people see. On top of burning more calories after the healthy meal you will also tend to eat less calories because you will be more satiated. Additionally, people who eat better tend to move and exercise more because they feel better. This mechanism demonstrates why eating healthy alone makes such a difference in caloric intake and burn on a daily basis.

What’s the point of exercise?

As I explained previously, the calories you burn during exercise are a relatively small amount of your total daily expenditure. So why even do it? There are many reasons and I will list a few:

-You can eat more
-Hormonal regulation
-Mood improvement
-Muscle mass retention
-Maintaining metabolism
-Cardiovascular health

There are many reasons to both lift weights and do cardio but none of them are to burn calories. To lose weight we need to be in a caloric deficit, and it’s way easier to create this deficit through nutrition than to substantially increase your daily caloric burn through exercise. However, I do always recommend moving more in general because the more you burn the easier it will be to eat in a deficit. While focusing on getting the structured exercise I continue to emphasize increasing your NEAT as well.

Should I still avoid carbs?

I’ll say it again, a calorie is a calorie. Except for protein and fiber, it does not matter where you get the rest of your calories from whether it’s carbohydrates or fat. Multiple studies have been shown that if you equate protein, fiber, and calories you will lose the EXACT same weight whether you eat high carb or low carb. Additionally, if you lose fat using either of these diets all health markers will improve including insulin sensitivity, cholesterol, and inflammation. Yes, if you lose fat using a high carb diet you will actually improve your insulin sensitivity as well as other blood markers. It is the fat loss that makes the difference. If you are in a caloric deficit this negative calorie flux completely overrides any increase in insulin levels. Study after study has shown these results, so I urge you to stop worrying about carbs and fat and to start increasing your protein and eat healthy food no matter how many carbs are in it. 

The unfortunate truth is that 95% of people who attempt to lose weight will put all the weight on plus more within three years. Yes this is a very sad statistic. So what is the key to being part of the 5% who keep the weight off? The most important factor is sustainability. What eating plan can you maintain for the rest of your life? What healthy foods can you prepare easily and enjoy that you can eat consistently? Answer these questions and you are on your way to keeping weight off for the long term.

In strength,

Mark Kolding, M.S.
Personal Trainer/Triathlon Coach
ACSM CPT
510-734-2817