Im sure you’ve heard to lose weight: It’s just a calorie deficit. Well that is 100% true. It’s a simple concept, but that doesn’t mean, that it’s easy. This article is going to give you all of the fundamentals of a calorie deficit explained.
A calorie deficit is the ONLY way you can burn fat. Whether it’s keto, juicing, vegan, fasting, slimming world. They all have one thing in common. They all get you in a calorie deficit. A lot of diets will make out, that they have a magic formula, that burns fat. They don’t. The only formula they have is making you eat less than you burn.
Calorie deficit explained – The fundamentals
Calories are a unit of energy, just like metres are a unit of length. The food we eat is measured in calories. The energy we expend is also measured in calories. Just like how the currency we earn is money and the currency we spend is money. Calories are the bodies currency.
If you spend less money than you earn in a month, you’ll lose money. If you eat less calories than, you burn over a month. If you spend more than you earn in a month, you’ll have extra money stored over. If you eat more calories than you burn over a month, you’ll have extra calories stored. Usually in the form of bodyfat.
So when you eat less calories than you burn. Your body has to find a way to compensate for the lack of calories coming in. So your body burns it’s fat. Your fat, is like saved money that’s needed in an emergency. In a calorie deficit, your body is treating it like an emergency. It’s using your savings to prevent you going into debt.
You’ve explained a calorie deficit, but how do I know how many my body is burning?
Use my calorie calculator. It takes your, sex, height, weight, age and activity and will spit out an estimation. It’s vital to know it’s a calculated estimation.
These are the factors, which influence the number of calories your body burns:
BMR – Basal metabolic rate
The number of calories your body burns when you do nothing. The calories burnt are from natural body functions, like your heart beating. This burns most of your calories in a day. This is 60-75% of daily calories burnt. This depends on age, weight, height and gender. The heavier you are the higher your BMR.
NEAT – Non-exercise activity thermogenesis
The calories burnt from all your daily movements. These movements aren’t exercise. For example, walking, fidgeting, cooking, cleaning. These burn more calories than exercise for most people. This article and this article, talk more about how NEAT can increase your calorie burn.
EAT – Exercise activity thermogenesis
Calories burnt through exercise. Pretty self-explanatory
TEF – Thermic effect of food
Calories burnt through the digestion of food. For your body to break down what you’ve eaten it requires energy. About 10% of your calories digest your food. So if you eat 3000 calories your body burns 300.
These combine to create you’re TDEE, the amount of calories your body burns.
It’s important to note, the more weight you lose. The less calories your body burns. Your BMR decreases when you’re lighter because your body has less cells so less work for the body to do.
Eating less calories
All foods have calories. Some more than others. The other end of the equation is to make sure the amount of food you eat, is less than the amount your body burns. Then your body will have no choice but to use the stored fat your body has to make up for the energy your body burns.
Final thoughts on a calorie deficit explained
Thats how every diet works. Eat less than you burn.
You’ll see a lot of people online claiming you can lose weight without counting calories. Yes, that is true. But whether you count calories or not, you still need a calorie deficit. Counting them means, you get a better understanding of how much you need to eat. Not counting means you have to rely on guesswork.
Some diets claim, you don’t need to eat less. That is false. I wish it wasn’t. But to lose weight, you need a calorie deficit and that will involve eating less . You can eat more food volume, by eating lots of water rich food, like potatoes and veggies. You can also increase volume by using less fats, like oil and nuts. But you still need to eat less calories.
Most of these diet’s cause a calorie deficit through over rules. Low carb diets, remove carbs, meaning you eat less calories. Clean eating removes processed food and sugar, meaning yes, you eat less calories. Slimming world use a point system, which is calorie counting in disguise. A vegan diet, removes all animal products, meaning you eat less calories.
If you want to know a sustainable way to do that read my article on flexible dieting. This is the one diet you can eat what you like, without any rules. Except of course, being in a calorie deficit.
Josh is a Registered Associate Nutritionist, with the Association for Nutrition (AFN). He completed his degree in Nutrition at the University of Roehampton in 2021. He passed with a First Class with Honours.
Josh is also a tutor for up-and-coming Personal Trainers, where he teaches a Level 4 Advanced Nutrition course. This is for Personal Trainers looking to upskill their nutrition knowledge. This is done at Norfolk Health & Fitness.