The formula for losing weight is simple, you just have to create a  calorie deficit by burning more calories than you consume.  Now this  week I want to share with you some very important information on how to  best determine your caloric needs.  So if you’re really serious about  weight loss you need to keep reading because there is a lot of very  valuable and helpful information here. 
The secret to weight loss is really understanding your Basal  Metabolic Rate (BMR) and Total Daily Energy Expenditure (TDEE).  Because  there is so much great information to cover here, I’ve decided to  divide this article into two parts. This week (part A) I’m going to  focus mainly on your BMR, while next week I’ll discuss and explain your  TDEE (Part B).
 Ok, so let’s look at your BMR.  Simply put, this is the number of  calories you’d burn if you stayed in bed all day. It does not include  exercise, typing on the computer, yard work, walking, talking, sitting,  driving your car, shopping or even thinking for that matter. Yet, your  BMR is important because it accounts for 60% to 70% of calories you burn  each day.  Wow, can you believe that!!!  Nearly two thirds of the  calories you burn every day are the result of your BMR which includes  calories burned for basic bodily functions such as breathing, blood  circulation and maintenance of body temperature.  So many people don’t  realize this but it is truly a key factor in weight loss.  Now I bet I  have your interest!!!
 So since exercising only accounts for 10 to 20% of the calories you  burn each day you need to look at ways of also increasing your BMR if  you are serious about weight loss. There are many factors that determine  your BMR, including your age, sex, height, weight, thyroid, diet , lean  body mass and genetics, but unfortunately you only have control over a  few of these factors.
 Take diet for instance.  Diet is something you can control and just  about everyone knows their diet is important for weight loss, but did  you know that reducing your calorie intake too much can result in your  BMR dropping as much as 20 to 30%?  You need to create a calorie deficit  if you want to lose weight, but you have to be careful that you don’t  reduce your calorie intake too much or your BMR will decrease. It  doesn’t make sense to go on an extreme calorie reduction diet that  causes your BMR to also decrease.  The smarter way to lose weight is to  reduce your calorie intake more moderately and then to also increase  your calories burned by exercising more.  The American College of sports  medicine (ACSM) says that the daily calorie level consumed for women  should never drop below 1200 calories per day and 1800 calories per day  for men. In, some cases this may still even be too much of a reduction  and could cause your BMR to drop significantly.  I’ll go more into this  in next week’s “Part B” of this article concerning your TDEE.
 Your lean body mass is also a BMR factor you can control, in fact,  it’s probably the most important.  The lower you body fat the higher  your BMR.  By the way, statistically men have lower body fat than women  and typically have a higher BMR of about 10 to 15%.  Ok, so a special  note to all the women out there…we need to work a little harder at  keeping our BMR’s from dropping.  But nonetheless, both men and women  need to work at keeping their BMR working optimally and the two biggest  things you can do to increase your lean body mass is to eat healthier  and lift weights.  I know, you’re probably thinking “what about cardio  activities?  Don’t they assist in weight loss and lean muscle mass?”   Well in the short run, the answer is yes, since cardio exercise burns  many calories at the exact time you are doing the activity. However, in  the long run, strength training is better for weight loss because it  causes people to burn extra calories not only during their workouts but  also in their day-to-day activities, which get this, even includes  sleeping!  However, before I continue on with my point of strength  training being a greater benefit to weight loss through developing lean  muscle mass, I do not want to discourage or discredit the importance of  doing cardiovascular activities.  Cardio activities promote  cardiovascular health which leads to a reduced risk for heart attacks  and strokes and promotes an overall better quality of life…so keep doing  your cardio!
 Now that I have made that point clear, let’s get back to discussing  the most prominent factor that affects your BMR….lean body mass.  Simply  put, the more muscle you have the more calories you will burn. I know  from posts I receive in my discussion forums that many women are afraid  of lifting heavy weights out of fear of gaining weight.  Unfortunately,  this myth really does a lot of damage by persuading a lot women not to  strength train.  The reality is that the only way to gain weight is to  consume more calories than you burn.  Weightlifting burns calories and  does not cause weight gain.  If you gain weight during a strength  training program it is not from the weightlifting, but instead comes  from the excess calories you have consumed or temporary water weight  gain. Without a positive caloric balance it is impossible to gain  bodyweight.  Let’s look at it this way, regardless, if you weight train  or not, you will gain weight if you consume more calories than you burn  each day. These extra calories will mainly be turned into body fat by  the person who does not train with weights, while the same extra  calories consumed by the person who trains with weights will be used to  create new muscle tissue. You might be thinking that you would rather do  cardio instead of lift weights to burn those extra calories. But  remember, lifting weights develops lean muscle mass and since muscle  takes up about one third the space of fat, you will not only look  leaner, but will also increase your BMR.  Since your BMR is responsible  for most of the calories you burn each day you would be foolish not to  take advantage of the best way to increase it.  And guess what?  Increasing your lean body mass increases your BMR and that translates to  burning more calories all day long, even while you’re sleeping.  Do I  have you searching for your hand weights yet?
 But wait, there’s even more!  As you age, incorporating a thorough  weight lifting program becomes even more important because your BMR will  decrease about 2% every decade after the age of 20.  This may not seem  like a lot, but a 2% decrease for a person with a BMR of 1500 means they  would burn 30 calories per day less than they did the decade before.  This translates into a weight gain of nearly 3 pounds per year without  taking into account any increase in calories consumed or decrease in  their activities or exercise routine.  This best way to counter the  decrease in your BMR as you age is to increase your lean body mass and  turn your body into a fat burning machine all day long!
 Courtesy of: Cathe Friedrich