Meeting #3 – Part 1: Calories, Calories, Calories

We had our third meeting, and the best one yet – thanks to all the lovely ladies that came out for the discussion!  The topic was calories, and the recap will be in two posts – first a summary of how to determine your caloric needs, and then some thoughts on what type of calories will make your body sing with happiness.

But first, a couple of announcements:

  1. We are moving to a monthly meeting schedule, the second Tuesday of each month.  The next meeting will be on October 11, at 6pm.
  2. The new meeting location will be the Plymouth Meeting Whole Foods, in the cafe area.  We gave it a try last night and there was lots of space.  Everyone is encouraged to come 15 minutes early to pick up a healthy snack to enjoy during the meeting.

And now, on to the main event – how many calories should you eat if you want to lose weight?

This was an interesting topic to research, and there’s a lot of conflicting information out there.   My mom always said you should eat 1200 calories a day to lose weight.  Yikes!  That’s not much food at all.  Some folks swear by  cutting out carbs, or fat, or sugar, or alcohol…the list goes on and on.  It’s tough to sort out the truth.

Honestly, though, it’s really just simple math – calories in, calories out.  Although many experts believe that not all calories are created equal, they all seem to agree you need to eat fewer calories than you burn in order to lose weight.  So here’s my best attempt at explaining the math:

A pound of fat = 3500 calories of stored energy.  To lose a pound of fat, you need to create a deficit of 3500 calories between what you burn and what you eat.  To lose a pound in a week, you need to create a daily deficit of 500 calories (7 days x 500 calories = 3500).  For some people it is easier to cut back by 500 calories, and for others it’s easier to burn off an extra 500.  Many people fall somewhere in between.

To get started, you need to determine how many calories you burn on an average day at your current weight.  To start with, everyone burns a certain amount of calories just to exist - this is called your Basal Metabolic Rate, or BMR.  Essentially, it’s the amount of calories your body would need to maintain your weight if you were in a coma.  Estimations differ on what that is, but there are calculators on the web to approximate your BMR based on age, height, weight, sex and body fat percentage: http://health.discovery.com/centers/heart/basal/basal.html

Be careful with this information, however – eating below this level can throw your body into starvation mode and cause your metabolism to slow down!  Some experts say you should never eat less than 20% above your BMR to avoid this effect.

Once you know your BMR, you can estimate the number of calories you burn on an average day by accounting for your basic activity level.  This link: http://nutritiondata.self.com/tools/calories-burned will help you with that.  One thing to note is that most people overestimate their activity levels.  If you’re an office worker, your activity level is likely to be sedentary, even if you do 30 minutes of cardio every single day.

OK – now what?  You know how much you’d burn in a coma, and how much you burn on an average day based on your normal activity level.  If you get some additional exercise, you can add it on top of your standard calorie burn – but be careful with using the numbers on your treadmill or heart rate monitor!  These values usually grossly overestimate what you burn, and they don’t account for the calories you’d be burning just by existing.  For example – a 150 pound woman might burns about 1 calorie per minute when completely sedentary.  That same woman would burn about 200 calories walking a very brisk pace for 30 minutes.  But she needs to subtract the 30 calories she’d burn if she weren’t walking – so the net is only 170 calories burned.

Let’s try an example, and determine a target daily count based on a hypothetical current weight & activity level, and how much we want to lose each week.  Using the first link above, a 160 pound woman, 5’5”, 35 years old, who holds an office job would have a BMR of 1484 calories per day.  If we apply the 20% rule to that, she would never want to eat below 1484 + 20% which is 1781 calories per day.  Using the second link, and choosing a sedentary lifestyle with 30 minutes of low impact cardio per day, her average daily calorie burn is about 2211 calories per day.  So to lose a pound a week, she could eat 2211-500 calories per day, or 1711.  But that’s a little below her BMR + 20%!  Instead of going too low on calories, she could bump up her daily workouts by 10 minutes or increase the intensity to create her target deficit.

Phew, this is all pretty complicated to figure out!  If you’re an analytical person (like me) you love this kind of stuff.  Fortunately, for the rest of the non-geek world, there’s a straightforward and simple alternative.  First, decide on a goal weight, then figure out how many calories it would take to maintain that weight at your chosen activity level, and finally just start eating at that calorie level right now.  Eventually (it might be slow but it WILL happen) that weight will become reality.  And you’d be surprised how many calories you can eat!  A 150 pound, 5’5”, 40 year old woman with a sedentary lifestyle would burn 1926 calories per day.  Add 45 minutes of running 3x per week and that averages out to an extra 200 calories per day, bringing the daily total to 2100!  That’s a lot of food, and if you choose whole foods such as fruits, veggies, lean proteins and whole grains, it can be an incredibly satisfying way to live.

So there you have it – the lowdown on calories.  Stay tuned for the next post by Abby on different types of foods and calories!

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2 Responses to Meeting #3 – Part 1: Calories, Calories, Calories

  1. Chris says:

    I enjoy reading this blog! I especially liked the link to the site that calculates your caloric need – what an eye opener. Also, the BMI link. I astonished my doctor this morning when we were talking about my weight he asked if I knew what mine was and I said 25.6! He dropped his little chart and stared on….. who is this strange woman who knows to the tenth what her BMI is! LOL!

  2. Abby says:

    LOL– That’s great! I’m sure that you are one of the few that can say that! BTW- Levin’s BMI is probably 10.5 :)

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