Understanding Calories and Weight Loss
When it comes to losing weight, understanding calories and weight loss is important. But is it really as simple as “calories in, calories out?”
Well, yes. And no.
Counting calories to achieve a deficit is a proven way to lose weight. But if it’s so simple, why do so many of us struggle to shed pounds?
In this post we’ll explain everything you need to know to understand how calories work and achieve your weight-loss goals.
What are calories?
A calorie is simply a unit of energy.
While most of us equate calories with food, technically speaking, anything that contains energy has calories!
When we talk about the calories in food, we are actually talking about kilocalories (1,000 calories). A kilocalorie (we’ll just call them “calories” from here on out) is the amount of energy required to raise one kilogram of water by one degree celsius.
When you eat and drink things that contain calories, you are putting energy into your body.
Your body needs energy to function, even at rest. Breathing, circulation, and growing and repairing cells all require energy. And of course, your body burns energy with physical activity — and the more intense the exercise, the more calories you burn.
But when you consume more calories than you spend, your body stores the excess as fat.
One pound of fat comprises about 3,500 calories.
How many calories should you eat each day?
The National Institute of Health (NIH) says that the average woman should consume about 2,000 calories per day and a man 2,500 to maintain a healthy weight. But every body is different!
To understand how many calories you need, you first need to determine your basal metabolic rate (BMR). This is the number of calories your body burns each day just performing basic functions. You can use an online BMR calculator to get a general idea of what yours is, or for a more accurate assessment, talk to your doctor or dietitian.
In addition to your BMR, your caloric needs are determined by your age, weight, sex, and activity level — and, of course, whether you’re trying to lose, gain, or maintain your current weight.
When you consume and expend roughly the same amount of calories in a day, you are in caloric balance. This is how you maintain your body weight.
If you consume more calories than you burn, you are in caloric excess and your body will store those extra calories as fat.
If you burn more calories than you take in, you are in caloric deficit and will lose weight.
Counting calories for weight loss
So it serves to reason that the fewer calories you consume, the more weight you’ll lose. Right?
Not so fast!
When you don’t get enough calories on a regular basis — called extreme caloric restriction (consuming less than 1,000 calories a day) — your body tries to protect you by going into what is often called “starvation mode,” shedding muscle, increasing its fat storage efficiency, and slowing down your metabolic rate. Not a good thing.
So simply restricting your calories isn’t always the answer to losing weight. It’s more of a balancing act.
Generally speaking, men shouldn’t eat fewer than 1,500 calories and women shouldn’t eat fewer than 1,200 calories per day.
To lose 1 pound of fat per week, you need to create a weekly deficit of 3,500 calories — or 500 calories per day. There are three ways to accomplish this:
- Eat 500 fewer calories each day
- Burn 500 extra calories each day
- Eat fewer calories and exercise to create a deficit
For example, you can create a 500-calorie deficit by eating 200 fewer calories and burning 300 extra calories at the gym.
Does it matter where my calories come from?
All calories are not created equal.
Most foods fall into one of three categories of macronutrients: proteins, carbohydrates, and fats. Proteins and carbohydrates contain 4 calories per gram, while fat contains 9 calories per gram.
Protein requires more energy to digest and metabolize, so it helps you feel fuller longer. Fats and carbohydrates, on the other hand, are metabolized faster, so you feel hungry again sooner. A lot of junk food (soda, candy, etc.) delivers calories to your body but few (if any) nutrients. These are called “empty” calories.
When every calorie counts, you want to get the most bang for your buck. Stay away from empty calories and fill up on nutrient-dense foods to keep you feeling satisfied and help your body function properly.