ROSIE - calculating calorie requirements

Calculating calorie requirements
 
Losing weight is a simple formula: calories in must be less than calories out. Simple? Yes. But there is so much more to it than that. Individual needs are so, so different and this is where it gets confusing. I weigh 62 kilos. My husband weighs 85 kilos. So, theoretically he should need way way more calories than me. But actually I eat so much more than him and maintain my weight. Slow metabolism simply can exist, I am lucky enough to inherit my mother's super dooper fast metabolism.
 
Below is a good way of working out your theoretical calorie needs; however, be aware that individual metabolic rates do vary. You will know if you have a slow metabolism, if you can go for long periods of time without food, if you just look at a cream cake and put on 2 lbs, well, I'm afraid to say you do have a slow metabolism. If you HAVE to eat regularly (and by this I mean you feel faint, dizzy and sick if you don't eat every 3 hours) to maintain your weight.
 
So, the formula. I am the worst mathematician and I can do this, so just bear with me. After the formula I will stick my own numbers in so you can see an example.
 
Estimate your basal metabolic rate (BMR)
BMR = 665 + (9.6 x W) + (1.8 x H) - (4.7 x Age) = Daily Calorie needs.
Where
W = weight in kilos
H = height in centimetres
Age = years
 
So my BMR = 665 + (9.6 x 62) + (1.8 x 165) - (4.7 x 31) = 1411.5 kcals per day.
 
Multiply your BMR by your physical activity level (PAL)
 
 
Physical Activity Level (PAL)
Description
Examples
1
Inactive
Sleeping/lying down
1.2
Sedentary
Mainly sitting/desk job
1.5
Moderately active
Some walking
1.7
Active
Daily walking or gentle exercise
2.0
Very active
Moderate daily training or sport
2.2
Extremely active
Strenuous daily training or sport
 
I would say that I am "very active"; I train 4 times a week quite hard and walk the dog (pushing the pram!) an hour at least every day. Plus I rarely sit down, except at work or to eat lunch! So I need to multiply my calorie needs by 2.0 = 1411.5 x 2 = 2823 kcals per day.
 
Another tip, if you're looking to lose weight then you should reduce your calorie intake by 10-20% ONLY. Any more and your risking slowing down your metabolism which equals weight gain!
 
If you want to count your calories, then do so. I personally don't- if I feel the jeans getting a little tight then I know I've been overdoing it. If I feel like I'm running on an empty energy tank then I eat a healthy snack. However, it is so easy to underestimate how much calories ARE in things then if you are trying to lose weight then it may be best to keep a food diary so you can tot up your calories. It will probably show you where you are going wrong and put you on the right track!