Calories are the energy currency your body uses to function.
Whether you're at rest, work or play, your body is constantly using calories to provide itself with the energy it needs to not only perform but also survive. Calories are used to keep your heart beating, lungs breathing and brain thinking. Without sufficient calories your body would cease to function.
When you exercise or work out your calorie (or energy) output is increased in order to allow your body to perform the tasks you require of it. If your calorie input is higher than its output you will gain weight and if your input is lower than your output you will lose weight.
This change in energy is called the energy balance equation.
The energy balance equation is the relationship between the calories you put into your body through food/drink and the calories you expend through maintaining homeostasis and any exercise or activity you perform. The energy balance has 3 basic rules:
1. You will gain weight if your energy input is greater than your energy output
2. You will lose weight if your energy input is less than your energy output
3. You will neither gain nor lose weight if your energy input is equal to your energy output
Your overall daily calorie needs are made up of a few different functions which explain the differences in calories needs from one person to the next.
Basal Metabolic & Resting Metabolic Rate
Basal metabolic rate (BMR) is the number of calories you need at rest to allow your body to function at its most basic level. This term, BMR is often used interchangeably with resting metabolic rate (RMR) and makes up the largest part of your daily calorie needs.
The Thermic Effect Of Food
In addition to your BMR there is also the thermic effect of food, which is the technical way of saying, the calories your body uses to digest the food you eat. This process accounts for a small portion of your daily calorie expenditure.
Non-Exercise Activity Thermogenesis
When trying to calculate your daily calorie needs you also need to account for Non-Exercise Activity Thermogenesis (NEAT). This is all the activity you do which is not related to sleeping, eating or exercising and relates to the type of job you work, how much you move during the day, housework and how fidgety you are.
It can account for a large amount of additional calorie output daily and explains why some people struggle to put on weight even eating whatever they want and vice versa.
Total Daily Energy Expenditure
TDEE for short, is the total amount of calories you expend each day, inclusive of the above and any exercise you do i.e. playing sports or resistance training.
How Do You Calculate Your Daily Calorie Needs?
Considering all of the above the simplest way to calculate your calories need is to use the following calculations:
• Fat Loss = Bodyweight in lbs x 12
• Maintenance = Bodyweight in lbs x 14
• Muscle Building = Bodyweight in lbs x 16
These calculations will give you a good starting point but you may find you're not quite hitting your sweet spot for optimal weight gain or loss.
What Is The Optimal Rate Of Weight Loss Or Gain?
Aim to lose weight at a rate of 1 - 2 lbs a week for optimal fat loss and muscle retention and aim to gain weight at a rate of 0.5 - 1 lbs a week for optimal muscle gain and minimal fat gain.
From here you can track your progress by weighing yourself daily and taking a weekly average. If you're losing weight too quickly, not quickly enough or gaining weight too quickly or not quickly enough then you can either:
• Add 100kcals (25g of carbs)
• Remove 100kcals (25g of carbs)
Then track your weight again to see if it fixes the problem. Keep using this tactic until you hit your sweet spot.
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