Do Calories Really Matter?
“Calories in, calories out are all that matter for losing weight.”
You’ve likely heard this phrase before. When it comes to health, there is an endless amount of info out there. Some is helpful, some hurtful and some contradictory.
Do calories matter? Yes. Are they all that matter? No. And despite the fact that they do matter.. Do you have to track them? Not necessarily.
So far this is as clear as mud. But stay with me.
What is a calorie?
Calories aren’t a tangible item. They are a unit of measurement. Like temperature is measured in units of degrees, a calorie is a unit to measure energy. By definition a calorie is the amount of heat needed to raise the temperature of one liter of water by one degree Celsius.
When you eat foods, they contain 1 of 3 macronutrients. Protein, carbs, or fats. These 3 macronutrients are where the majority of your calories come from. The final source of calories is alcohol.
As these foods are digested, the energy that’s stored in the carbon bonds are released and can eventually be used to power other processes in the body like keeping your:
-blood warm
-heart pumping
-gut digesting
-muscles contracting.
Here’s a quick overview of the caloric content of macronutrients.
1 gram of protein = 4 calories
1 gram of fat = 9 calories
1 gram of net carbs (carbs minus fiber) = 4 calories
1 gram of alcohol = 7 calories
If you total up the intake of all of these this equates to total calories eaten.
If you burned more calories than this, you would have lost weight. If you burned fewer calories than this you would have gained weight. This is factually true, but here are some issues that arise.
#1 - You don’t know how many calories you are burning
With a calories in, calories out equation you don’t actually know how many calories are going out. It is only an estimate. How many calories did you burn while fidgeting at the desk? How many did you burn on the treadmill or with your daily step count? You don’t have these answers specifically and they will vary from person to person.
#2 - Error in measurements
You can track everything and still be off. Every restaurant meal becomes a complete guess. And google the calories in a chicken thigh and you will get 2 different answers. Are you measuring exactly or estimating at times? It’s not realistic to be perfect with your measurements. There will always be user error, especially for novices.
#3 - Errors legally allowed in packaging
The packaging can legally be 20% off in either direction with calories. So something listed as 100 calories could be as low as 80 or as high as 120 calories. That doesn’t sound like a lot but that means you could be eating anywhere from 1600 to 2400 calories in a day if you counted 2000 calories for the day. A massive swing that could be the difference between gaining or losing weight.
#4 - What you eat determines your calorie burn
Here is one of the biggest arguments against “calories are all that matter.” The macronutrient content of the foods you eat affects the number of calories that you burn. Digestion is a lot of work for the body. Up to 25% of the calories from protein are burned off during the digestion process alone. For every 4 calories per gram or protein, only 3 are left after digestion. This is called the thermogenic effect.. And it’s nearly double for protein what it is for carbs and fats.
If you ate 2000 calories worth of carbs and fats or 2000 calories worth of protein, you would burn 200 calories per day eating protein resulting in additional weight loss.
#5 - What you eat determines your body composition
So far we have been mainly talking about weight loss. But most people want to lose fat, not weight. Eating too many calories will cause fat gain and weight gain. Eating fewer calories would cause weight loss (hopefully from fat). But if your body isn’t getting enough protein, it cannot spare muscle mass. It physically doesn’t have the resources available to repair the muscle tissues and the result will be a loss of muscle mass.
On the flip side, a high protein approach gives your body what it needs to maintain muscle mass. Combine this with resistance training and the body has the stimulus it needs to maintain muscle and potentially even build more of it.
This is another example of how WHAT you eat matters in combination with how much you eat.
#6 - Micronutrients matter
Calorie burn is affected by more than just your activity level and the macronutrients (carbs, fats, proteins) you eat. Your hormone health matters. Eating real foods that contain higher levels of vitamins and minerals promotes better hormone production which affects every aspect of your health.
Eating processed foods can lower testosterone levels and deplete your body of valuable vitamins and minerals. This can lead to worsening metabolism over time. And this doesn’t account for poor gut health or inflammation from processed foods that negatively affect your body beyond just weight gain.
#7 - Most people don’t count calories
Even if calories were the only thing that matters, the average person doesn’t actually track their intake, myself included. So the calorie conversation becomes a bit irrelevant to the average person. This doesn’t disprove the laws of thermodynamics (calories in, calories out) but it does make it less applicable day to day.
So what’s the verdict?
When it comes to weight loss specifically, the answer is absolutely, calories matter. There is research to support people losing weight eating nothing but twinkies while being in calorie restriction.
But some foods make you hungry while others keep you full. And some give you energy while others make you tired. You could lose weight eating nothing but twinkies but be prepared to lose muscle, feel terrible and be starving throughout the day. Like other unsustainable weight loss attempts, eventually this short term success is followed by a crash and burn.
Friday we will discuss how resistance training helps a 70 year old keep the muscle and metabolic health of a 30 year old in part 2 of the “Aging in Reverse” series.
Until then,
Brett
Brother2Brother
"I took my daughter to the aquarium last month but we didn't stay long...There's something fishy about that place."