Each person has varying nutritional needs. The amount of energy you need and food you consume each day will depend on your gender, age, body weight, level of exercise and general activity. Not only will energy needs vary from person to person, but your energy levels also vary on a day-to-day basis. As such, there is no one-size-fits-all approach.
When you consume less calories than you burn, you are in a calorie deficit. In order to lose weight, you must be in a calorie deficit. As such, it’s important to understand how many calories you need on a day-to-day basis.
The F45 Challenge is a calorie-controlled diet. The meal plans consist of approximately 1,900 calories for males and 1,300 for females. If you are training regularly, more often than not, you will need to add calories to your diet.
How do you know how many calories to consume (or not consume)? One way is to use a calorie calculator. F45 recommends using the Mifflin St Jeor equation to estimate calorie needs.
The equation first determines your ‘basal metabolic rate,’ the number of calories your body needs to function at rest and to perform basic body functions.
To determine your BMR, use the following formula:
MEN: Resting Metabolic Rate = (9.99 X weight) + (6.25 X height) – (4.92 X age) + 5
WOMEN: Resting Metabolic Rate = (9.99 X weight) + (6.25 X height) – (4.92 X age) – 161 Equations use weight in kilograms (kg), height in centimeters (cm).
Once you determine your BMR, you will need to determine your total daily energy expenditure (or ‘total daily calorie burn’). You can do this by multiplying your BMR by your activity level, as set out below.
1.2 If you are sedentary (little or no exercise) = BMR x 1.2
1.375 If you are lightly active (light exercise/sports 1-3 days/week) = BMR x 1.375
1.55 If you are moderately active (moderate exercise/sports 3-5 days/week) = BMR x 1.55 1.725 If you are very active (hard exercise/sports 6-7 days a week) = BMR x 1.725
1.9 If you are extra active (very hard exercise/sports & physical job or 2x training) = BMR x 1.9
The total number is your estimated daily calorie burn.
Generally, for healthy and sustainable weight loss, it is recommended that members consume 500 calories less than their total calorie burn for a day. However, keep in mind that individual needs vary.
As a general rule of thumb, adding 500 cal/day above your baseline energy requirements (those needed to maintain weight) in conjunction with including resistance training will result in muscle gain.
Importantly, you should not consume less calories than your BMR. Your body needs calories to function. If you consume too few, it can lead to health complications.