Losing Weight Calorie Deficit: What Is It & Why Is It So Important for Weight Loss?

The phrase “calorie deficit” is thrown around a lot, but what exactly is a losing weight calorie deficit? And do we really need one for fat loss?

Let me make this clear from the very beginning: whatever I say about calories, just know that they are NOT bad, and we NEED enough of them to survive and function properly. Under-eating (an extreme calorie deficit) is NEVER the answer to healthy and sustainable weight loss.

This post is all about a losing weight calorie deficit and why it’s so crucial for weight loss.

*Note: This post includes several Amazon affiliate links, which means I’ll receive a commission if you purchase through my link (at no extra cost to you). Please read full disclosure here. Also, I am not a doctor or dietician. I am a personal trainer. It’s always best to speak with your doctor before making any changes to your diet and/or lifestyle.

A guide to the calorie deficit for women:

What we’ll cover…

Calories: what are they?
What determines caloric value?
What does it mean to be in a calorie deficit?
How do I make sure I’m eating in a deficit?
Why low-calorie & restrictive diets ALWAYS fail

After reading this post, don’t forget to check out…

You Need To Try This Life-Changing Easy Weight Loss Tip

4 Valuable Benefits of Resistance Training: Does Weight Lifting Burn Fat?

What is a calorie?

In simple terms, a calorie is literally just a unit of energy. Using calories is a way of measuring the fuel we feed our bodies; similar to measuring with gallons when we fuel our cars with gasoline.

Each and every person requires a different amount of food (calories) to be properly fueled throughout the day. Some determining factors include gender, height, weight, age, body composition (muscle to fat ratio), and activity level. As a competitive powerlifter, my eating habits may be very different from most others.

What determines caloric value?

Unfortunately, not all foods are created equal. The calories found in an ounce of butter are not at all equivalent to those found in an ounce of broccoli, but why is that?

The amount of calories an individual food has is based on the amount (in grams) of carbs, fat, and protein it contains.

Carbs: 4 calories per gram

Protein: 4 calories per gram

Fat: 9 calories per gram

As you can see, fattier foods such as butter or cheese will have a much higher caloric value than their carb or protein-filled counterparts. Although, this does not imply that fatty foods should be completely off limits for someone wanting to lose weight; they only need to be eaten in moderation as with any food.

What does it mean to be in a calorie deficit?

When someone eats a calorie deficit diet, it means that he/she is consuming fewer calories than he/she burns throughout the day. Eating in a calorie deficit is the ONLY way to lose fat. Keep in mind that it is absolutely possible to lose weight calorie deficit no exercise.

Our bodies are constantly using energy during the day and the night—meaning we are burning calories all of the time, even without any physical activity. Non-effort calories burned are referred to as our BMR (basal metabolic rate), while calories burned from doing exercise are called active calories.

How many calories should I eat to lose weight?

Avoid being too restrictive with your eating habits, as restrictiveness may cause binge eating habits. Any food can fit into a so-called “diet;” it’s really all about balance. Some people do well tracking their food and calories, while others would rather eat mindfully.

I personally track my food, and I’ve used the app MyFitnessPal for several years now. Your approach is really up to you and your goals as an individual. As long as the number on the scale is going down, you know you’re successfully eating in a deficit. However, know that it is also very possible to be in too extreme of a deficit.

You can also try an online losing weight calorie deficit calculator, but you should know that the results will never be 100% accurate.

Generally, the heavier a person is, the more weight he/she can drop safely in shorter periods of time. For most people, a good rule of thumb is to eat in a calorie deficit to lose 2 pounds a week or less.

Why low-calorie & restrictive diets always fail

Weight loss should be considered a lifestyle change rather than a temporary fix. Quite frankly, an extreme calorie deficit diet (anything under 1,200 calories) is very unhealthy and not sustainable in the long term.

Know that 99% of people cannot stick to such restrictive eating habits, which causes them to binge eat or give up on their diet completely. This is why sustainability is so important; the way in which you eat needs to be doable for the rest of your life.

The takeaway

A calorie is just a unit of fuel we use to feed our bodies on a day-to-day basis. Consuming too many calories will result in fat gain while consuming too few calories will initiate fat loss. You can absolutely lose weight calorie deficit no exercise.

The amount of food a person needs to be properly fueled is dependent on multiple factors: gender, height, weight, age, body composition, and activity level are a few.

Some people may track their calorie intake to stay consistent with their weight loss goals, while others may prefer to eat mindfully. Weight loss should always be viewed as a lifestyle change rather than a temporary fix.