The recommended daily calories for adult men are 2500kcal and for women the figure is 2000kcal. If you want a reasonable idea of the number of calories you should be consuming to maintain weight, a few calculations need to be completed. The Henry equation is the recognised energy estimation calculator in accordance with the British Dietetic Association.
To estimate your requirements, factor this simple calculation for your age:
Male:
Aged 18-30 >>>>> 16.0 x weight (kg) + 545 = ……..
Aged 30-60>>>>> 14.2 x weight (kg) + 593 = ……..
Aged 60-70>>>>> 13.0 x weight (kg) + 567 = ……..
Aged 70+>>>>>>> 13.7 x weight (kg) + 481 = ……..
Female:
Aged 18-30 >>>>> 13.1 x weight (kg) + 558 = ……..
Aged 30-60>>>>> 9.74 x weight (kg) + 694 = ……..
Aged 60-70>>>>> 10.2 x weight (kg) + 572 = ……..
Aged 70+>>>>>>> 10.0 x weight (kg) + 577 = ……..
(Henry, 2005)
EXAMPLE: 26 year old, 80kg male
16.0 x 80kg + 545 = 1825kcal per day (BMR)
EXAMPLE: 29 year old, 60kg female
13.1 x 60kg + 558 = 1344kcal per day (BMR)
(NOTE: ‘kcal’ is commonly known as ‘calories’ & ‘BMR’ = Basal Metabolic Rate)
These figures will give you the amount of energy your body requires to maintain bodily functions. Physical activity will require additional calories.
We must, therefore, add a ‘physical activity level’ (PAL).
PAL:
Light occupational activity: Non active= Male- 1.4 Female- 1.4, Moderately active= Male- 1.5 Female- 1.5, Very active= Male- 1.6 Female- 1.6
Moderate occupational activity: Non active= Male- 1.6 Female- 1.5, Moderately active= Male- 1.7 Female- 1.6, Very active= Male- 1.8 Female- 1.7
Moderate/Heavy occupational activity: Non active= Male- 1.7 Female- 1.5, Moderately active= Male- 1.8 Female- 1.6, Very active= Male- 1.9 Female- 1.7
(Elia, 1990)
To add a PAL you need to take your BMR i.e. your estimated calorie requirements for resting alone and multiply it by the appropriate PAL (as shown above).
EXAMPLE: 26-year-old, 80kg male
This person trains intensely a minimum of 5 days a week, and also works as a labourer on a busy building site, therefore we would deem this individual to be very active with moderate/heavy occupational activity (use the PAL that best applies to you)…..so apply the appropriate PAL to the above 80kg male example as follows:
1825kcal (BMR) x PAL of 1.9 = 3468kcal per day to maintain this person's weight relative to his physical activity levels.