Wrote this in another thread but wanted to add it to this so i don't lose it, and it's easy to find for copy/paste purposes:
Setting a Diet:
Calculate calories burned per day (fitday does this automatically) using the BMR calculation.
Men: 66 + (6.3 x weight) + (12.9 x Height in Inches) - (6.8 x age) = Basal Metobolic Rate
Women: 655 + (9.6 x weight) + (1.8 x height) - (4.7 x age) = Basal Metobolic rate
Use this final number and then there is a multiplier introduced to estimate it based on your daily activities (stuff you do nearly EVERY DAY) I don't count workouts in this factor because I track those calories with fitday counter)
So take above number and multiply accordingly:
Sedentary (Desk job, Very low daily activity: x 1.2
Light Activity (Office type job but with moderate moving): x 1.375
Moderate Activity: x 1.55
Very Active (Very physical job, or daily athletes): x 1.725
EXTREME (Speaks for itself): x 1.9
So let's take "Joe" and say he is 250lbs. 6'0" is 30 yrs old, and works in the office, or is a truck driver that is always on the road, lots of sitting.
66 + (6.3 x 250 = 1575) + (12.9 x 72" = 928.8) - (6.8 x 30 = 204)
66 + (1575) + (928.8) - (204) = BMR of 2299.8 easily rounded to 2300
So take this 2300 and apply the multiplier (sedentary = 1.2) So 2300 x 1.2 = 2760 calories / day as his BMR, or I like to call this the "maintain" number.
The fitday calculator uses a different method which is slightly lower than this method I believe, but this is a tried and true method you can compare with.
Other info: 1 lbs. = 3500 calories
Example: If I want to cut 1lb. / week I need cut 3500 calories per week from my BMR (the number you just got above) which per day that is 3500/7 or 500 calories/day below my BMR to lose weight. If I want to gain a pound a week, I need to be over my BMR by 500 calories.
Now, these numbers are before specific workout calorie burns. So use fitday to track your activity too, say for instance: "Joe's" BMR is 2760 calories / day. He wants to lose 1lb. / week. So he tracks his Calories, he takes in 2400 calories per day for a week, without any change to his exercise routine. So he is cutting 360 calories a day, which isn't cutting enough to meet his 1lb. / week goal. But if he adds a 20 minute cardio that cuts an extra 300 calories per day (you can easily burn this much walking / light jogging) now he is cutting 660 calories a day which means he will overshoot his goal of 1lb. per week. Which is great.... right?
Well, the trick that I see is, the BMR is constantly going to change because it's calculated from your weight. This is why people platue when on "diets" where they are eating a set amount or a scheduled diet. As they lose weight, their body doesn't naturally burn as many calories, it's starting to say "ok I can slow down i have to save some of these calories in case there is a drought in intake!) So you have to constantly adjust your diet to meet the goals of your weight loss. This is also why diets start out with awesome results, but quickly decline in results as the fat starts to melt, people "maintain" the same or similar calorie intake and they aren't cutting as much per week. I have set my personal goals to lose 2lbs. / week, and if I make it through the day and find that I have extra calories left to spend, I just tell myself hey, that's extra weight coming off!
One last note that I have learned: you CAN cut calories in general and lose weight, hell you can still eat at McDonalds every day so long as you don't go over your calorie limit. I am not suggesting it cuz it's unhealthy in a lot of the other toxins you put in your body, but a calorie is a calorie when it comes to losing weight. However, the body will not differentiate between muscle/fat as it starts to break down your body to make up that difference between intake and burned calories. This is why you want to make sure a significant portion of your calories are coming from Protein intake. Protein will build lean muscle, while almost forcing your body to target the fat cells instead of musle cells to break down. It is suggested that you break it down to at least 1/3 protein, 1/3 carbs, 1/3 fats (NOT trans fat, but that's another topic) You can adjust this accordingly, as I'm pushing to lose weight and build lean muscle, I am pushing for more like 40% protein, 40% carbs, 20% fats.
I like being able to tailor my own diet for how I feel that day, and just make sure it hits my marks to see results =-) Also good to note, that when you update your weight, fitday auto updates your new BMR and adjusts that in your calorie budget. Making it very handy to update your weight daily (recommended to weigh in first thing in the morning after urination, as this is when your weight is most consistant)