There are two ways to create a calorie deficit:
- Reducing calorie intake – changing what and how much you eat
- Increasing calorie expenditure – in the form of exercise
How does being in a calorie deficit help you lose weight? It puts you into a ‘catabolic’ state, when the body is breaking down muscle and fat for energy.
If you cut 500 calories a day from what you normally eat, you can expect to lose about 1 pound – 0.5kg – a week, which is a healthy amount as per CDC guidelines.
Calories are the units of energy we get from food and drink. To lose body fat, a calorie deficit is needed – that means eating less calories than you burn. If you were to add calories because of let’s say working out and different body goals then that be considered “bulking” but thats a different topic.
A calorie deficit is when you take in fewer calories than you expend in a day. Every human has a unique Basal Metabolic Rate (BMR), which indicates how many calories their body burns just by doing normal everyday functions, such as breathing, digesting food, removing waste products and cognitive function.
Factors that affect BMR include age, gender, height and bodyweight, genetics.
Imagine your BMR as the number of calories you would burn if you stayed in bed and slept all day. It doesn’t take into account your lifestyle and most people’s BMR will be fairly low – around 1,500 calories for adults.
What Happens to Calories?
The body uses the calories it gets from food to fuel your metabolism, digestion and physical activity. When the number of calories you’re eating equals the number of calories you’re burning for energy, your weight will remain stable.
Calories = Energy
Once your body’s energy needs are met, any extra calories get stored – some in the muscles as glycogen (the main source of fuel for our cells), but most as fat. So, if you eat more calories then you burn – known as a calorie surplus – this will cause weight gain. By contrast, if you consume less food than you need for energy, you will lose weight.
So Where To Start?
There are several studies that prove being in a calorie deficit is the only way to lose weight.
Any type of diet – whether it’s the paleo and keto rely on a calorie deficit to work. It’s advisable not to exceed a deficit of 500 calories a day.
I would advise people to achieve this deficit by burning more calories, rather than restricting food intake.
That is to say, burn your 500 calories a day through cardio exercise and resistance training, rather than reducing the amount you eat. The reason for this is that it is less likely to lead to cravings and disordered eating.
To achieve a calorie deficit you need to first work out your Basal Metabolic Rate (BMR) – the number of calories your body needs to achieve its most basic life-sustaining needs at rest. There are lots of online calculators to help you do this.
Once you know your BMR, you need to include factors like how active you are and how much exercise you do.
This calculation is your Total Daily Energy Expenditure or TDEE, which is a more accurate representation of how many calories you actually burn in a day.
To be more specific, if your TDEE is 2,500 calories, you would need to eat 2,000 calories per day to lose 1lb per week.
Then once you start losing weight you will need to recalculate your TDEE to work out your new daily calorie deficit figure. “Once you have lost some weight, eat at maintenance level – the same number of calories as your TDEE – to make sure you don’t gain the weight back.
Cravings are not your body’s way of sabotaging weight loss or health goals. Cravings are actually one of the key ways our bodies communicate with us what they need. Plus, if we have a major craving for delicious tacos and force ourselves to eat another boring salad instead, it can lead to a bad relationship with food. Now that will sabotage your health goals.
Instead opt-out of unhealthy snacks and desserts for healthier options. If you’re having a sweet tooth after dinner grab a piece of dark chocolate.
When in doubt drink more water!