Measuring Calorie Expenditure with a BodyMedia

 know I’ve been M.I.A. for a long time, but I’m back because I have something really interesting to talk about: my BodyMedia!

What’s a BodyMedia?

A BodyMedia is a on-body device that tracks your footsteps, heartrate, sleeping patterns, and daily calorie expenditure, and then uploads them to an online dashboard for you to easily view and track.

It looks like a wristwatch worn on your upper left arm, but in fact it’s a sophisticated device that constantly captures data on your movement, skin temperature, and energy expenditure, then uses this information to determine your caloric burn. It’s more sophisticated than a pedometer or heart rate monitor because neither of those can accurately measure calorie expenditure–this does. Of all the products out there, this is the most accurate, with no guesswork or estimation on your part. You can learn more at the BodyMedia website.

Why Use A BodyMedia?

The BodyMedia produces so much data that I haven’t had time to explore all of it’s potential uses, but for now I’m going to focus on calorie tracking. If you’ve ever tried to lose weight, chances are at some point you’ve thought about calories. Too many people obsess over counting and measuring and tracking every bite of food in order to hit some magic calorie goal without ever stopping to consider whether this is the right amount for their body and weight loss goals. Or they spend hours surfing the web and reading articles and crunching numbers trying to figure out how many calories they just burned at the gym and how many miles they need to run to “burn off” last night’s dinner. Or they get hung up on hitting the right number of “net calories” *cough everyone on tumblr cough*, a concept that is inherently meaningless.

None of this makes sense, and none of this is the right way to think about food, exercise, and weight loss. It doesn’t make sense to pull a calorie goal out of thin air without first considering your calorie expenditure. It doesn’t make sense to meticulously track your exercise calories when they’re really just a rough estimate. And it doesn’t make sense to fixate on the calories you burn in an hour at the gym without thinking about the calories you burn during the other 23.

Calories aren’t just something that you burn off running on the treadmill; they’re units of energy that your body uses constantly to survive. Your body doesn’t just shut off when you’re not formally exercising; it’s burning calories constantly as your working, studying, eating, sleeping, and otherwise going through the motions of daily life. This is why trying to eat back your “exercise calories” to hit 1200 “net calories” is so silly: your body doesn’t differentiate between “exercise calories” and any other calories–all that matters is that your intake is less than your output.

Problem is, how do you know your calorie output? A magazine article can’t tell you. An online calculator can’t tell you. And the computer screen on the elliptical sure as heck can’t tell you. These estimates are a good place to start, and they’re certainly better than pulling a number out of thin air. But if you’re going to let your life revolve around those numbers, then you should at least make sure they’re the right numbers, right?

And that’s where the BodyMedia comes in. It eliminates the calculations and estimations and guesswork by giving you an accurate picture of your daily calorie expenditure. It tells you more about your own body than a doctor, trainer, or one-size-fits-all formula ever could. If your goal is to lose weight, it will enable you to calculate exactly how much you need to eat to reach your weight loss goals, allowing you to avoid sabotaging yourself by eating too much or too little. Moreover, you will be able to see the impact that different exercises, activities, and eating styles have on your body both at the time and throughout the day, helping you to find the lifestyle that is best for YOU.

Why I’m Using A BodyMedia

I get asked this all the time at work when my coworkers or tables see my BodyMedia! Right now I’m just using it to gather data and learn more about my body. I’m not actively trying to lose weight in the sense that I’m tracking or limiting my calorie intake–I’m just curious about my calorie expenditure. Specifically I’m interested in how weight-lifting impacts calorie expenditure in the short-term (how much does it increase calorie burn on a daily basis) as well as the long-term (can it permanently increase your metabolism?) I’m also curious about how much I’m burning at work waiting tables.

My BodyMedia Data

First here’s some background on me: I’m 22 years old, 5’8, and about 150 lbs. For the past month, I’ve been lifting heavy weights for 30-75 minutes 4-5x/week. I also have a very active job waiting tables 30-40 hours/week, and am usually fairly active when I’m not at work (biking, housework, running errands etc). Based on BMR calculations, my BMR should be around 1520 calories, meaning that my calorie expenditure should be about 2600 – 2900 assuming a high activity level. I’d estimate I eat about 3000 calories per day, but that’s just a guess since I don’t currently track calories.

I’ve been wearing the BodyMedia since November 9. Shown below are 17 days worth of data (rounded to nearest 10):

During this 17 period, I burned an average of 3290 calories per day. My calorie expenditure ranged from 2430 to 3860 calories. I expended over 3000 calories on 13 out of the 17 days.

My first reaction was, holy shit, no wonder I’m always hungry! This explains why I eat so much! My second reaction was to wonder about the variance from day to day–that’s almost a 1500 difference between the highest and lowest days!

However, this disparity makes sense if you take into account my activity level, particularly the two biggest factors: lifting weights and working. I’ve reproduced the data below using an “L” to indicate days that I lifted, and “W” to indicate days that I worked.

During this 17 day period, I worked 14 days and lifted 10 days. There were 8 days when I lifted and worked, 6 when I worked but didn’t lift, 2 when I lifted but didn’t work, and 1 when I did neither. I summarized the averages for each category below:

  • Worked and lifted (8 days): 3540
  • Worked but didn’t lift (6 days): 3100
  • Lifted but didn’t work (2 days): 3260
  • Didn’t lift or work (1 day): 2430
  • Overall worked vs didn’t work (14 days/3 days): 3350 vs 2980
  • Overall lifted vs didn’t lift (10 days/7 days): 3490 vs 3000


Right now my conclusions are preliminary because I don’t have much data–I just wanted to share what I had now! However, here’s a few of my thoughts right off the bat:

  1. First off all, I’m burning a LOT of calories. Significantly more than you’d expect based on standardized calculations for my age, size, and activity level. It’s a good reminder that estimations are just that–estimations–and the standard 2000 calories/day doesn’t apply to everyone–if you’re young and active you probably can and should be eating more than that.
  2. Lifting makes a difference. I average almost 500 calories more on days that I lift versus days that I don’t (3490 vs 3000). HOWEVER, this doesn’t mean that I necessarily burned 500 calories during that particular hour of lifting–just that lifting increases overall daily burn (the BodyMedia can show the exact calorie burn during a particular time to prove my point, I just haven’t analyzed it that deeply yet).
  3. Also just because I average 3000 calories per day on my days off from lifting doesn’t mean I’d burn 3000 calories anyway if I’d never picked up a weight. Your metabolism depends on your general pattern of activity, not just your day-to-day activity, and I have a feeling that if I took a month off lifting, my baseline would be much lower. I’m not going to do this on purpose, but it might occur naturally, hence my effort to constantly gather data for comparison purposes.
  4. Activity level matters too: an active lifestyle beats hours of cardio. Over these 17 days I averaged 370 calories more on days that I worked (3350 vs 2980). Moreover, when I look at the breakdown of individual days, I can see a big difference–all the days I hit over 3600 calories were ones I worked long, busy shifts and/or was active outside of work (in addition to lifting). Note that none of this is “formal exercise” but it still burns calories.
  5. My metabolism didn’t used to be this fast. In fact, my whole life I thought I had a pretty slow metabolism, based on the fact that I was overweight as a kid despite having normal eating habits. But I believe that you can increase your metabolism by weight lifting and by EATING, and this supports my belief.
  6. On the other hand, I don’t think I’m eating and expending exponentially more calories than the average person–I just think I’m more aware of it. Most people can and do eat more than they realize, but they aren’t really tracking their intake so they just assume they’re eating the “normal” amount you commonly hear thrown about: 1500, 1800, 2000 etc. When people do track calories it’s usually because they’re trying to lose weight, so that number isn’t going to be representative of an average day. And everyone underestimates.
  7. Based on this you can see why low-calorie diets are often doomed to fail. If Joe Schmo thinks he’s eating about 2000 calories a day, since that’s what the cereal box says (seriously, I’m pretty sure this is where I got my idea of a”normal” amount of calories from), then a 1500-calorie weightloss plan sounds reasonable. But in reality, he’s eating more like 3500 calories a day, he just doesn’t know it. So when he goes on a 1500 calorie doctor-approved diet plan, he feels like he’s starving–because he literally is. After a few days he can’t take it anymore and goes on a fast food binge. Or decides dieting is impossible and gives up altogether. Whereas if he had changed his target to 2500 calories he could having stuck to the diet for much longer, steadily losing 2 lbs/week until he hits his goal.

Stay Tuned…

I need to wrap it up for now, but I’ll be back with more posts as I get more data and delve more deeply into the data I have. I hope this was helpful and feel free to get in touch with any questions; I intend to be more active on here from here on out!


3000 Calories

Item #1: I’ve been eating ~3000 calories/day over the past month, up from ~2500 in mid-March through mid-May. I don’t have an exact number because I haven’t regularly tracked calories for months now and I eat out a lot so I don’t know the calorie content for most of my food. But I can estimate my average by tallying up whenever I have what I consider a low calorie day (ie when I think “wow, I’ve barely eaten all day”) It’s always at least 2000 calories. And that’s pretty rare. And I know there must be some days when I’m consuming upwards of 4000 calories when you include alcohol. So I think my average is closer to 3000 than 2500.

Item 2: Most of those additional calories were essentially discretionary calories from desserts, restaurant food, and carbs I don’t normally eat. It’s not that I was going out out of my way to eat extra treats, it just I didn’t avoid it when the opportunity presented itself. First there was eating out with my family and friends over the week of my college graduation: bread, cake, nachos, chocolate chips, fro-yo by the pound, and of course alcohol. Then in Costa Rica I ate chips and salsa, nachos, burritos, tons of banana bread, and copious amounts . And over the past week at my grandparents and at home I ate about 2 loaves of pumpkin and zucchini bread, brownie bars, tons of cake, chocolate chip cookies, fro-yo, bread, cheesecake, 1/2 a pan of Ghiradelli brownies. Additionally, most of my healthy meals were higher fat versions than normal due to use of butter, olive oil, cheese, avocados, and sauces/dressing in restaurants and cooking.

Item #3: Over the past month, my body has finally been changing. Obviously my weight was changing from January to March as I lost weight. But my body hadn’t really changed after that. It was frustrating because I felt like all the time I spent in the weight room wasn’t making a difference in my appearance. Sure I enjoyed it, and sure it sustained my ability to eat a lot, but I wasn’t seeing any muscle development. Then right before I left for Costa Rica, it was as if all of a sudden everything changed: my arms got more cut, my legs and glutes got harder, my waist looked smaller. Even my cheek bones looked more defined.

I couldn’t figure it out. Was all this junk food somehow good for me? Was it providing me with nutrients that I had inadvertently been lacking? Fat maybe? Should I have been on a high-fat diet all along?

Then yesterday it suddenly hit me with a flash. The increase in calories and changes in my body were probably correlated, and my body was responding positively to the extra calories. When I thought about it, it made sense. If 2500 calories is maintenance level for me, then I need to eat more than that to continue to build muscle. And it didn’t matter where they came from, just that they were there. It’s not that cake and nachos somehow have beneficial nutritional properties, just that I wouldn’t have inadvertently consumed that many calories from healthy foods alone.

So what am I going to do with this insight? Nothing actually. (Besides, you know, sharing it with you guys). I’m just going to keep eating whatever I want when I’m hungry and see what happens. That is literally the easiest approach possible and why mess with what’s working? Especially since I could be wrong so I’m not going to deliberately manipulate my behavior based on a theory.

Basically I just wanted to share this with you because:

  1. I want to be as honest and accurate about my eating and exercise habits, therefore I feel obligated to update my previous estimate of ~2500 calories for accuracy
  2. I’m trying to pay attention to the impact that various inputs have on my body, so keeping a record is beneficial to me and to anyone else that can apply what I’ve learned.
  3. No one on tumblr eats as much as I do. No one. There is a such a skewed sense of what is healthy and normal. I’m trying to combat that by showing that you don’t have to starve yourself to improve your body and maintain your weight.
  4. There could be benefits to increasing your calories that you don’t even realize, and you might be inadvertently shooting yourself in the foot by restricting your intake.

So there you have it. And I will keep you guys posted!

Confession: Sometimes I Feel Guilty About How Much I Eat

Copied from my tumblr yesterday morning. Going to make more of an effort to cross-post to here too!

Sometimes I feel guilty about how much I eat. 

Not like “OMG I’m going to get fat guilty” but more like “why do I get to eat this much” guilty. Or alternatively I wonder how other people can eat so little, or how the heck I ever used to.

Case in point: yesterday, ate about 1850 calories according to LoseIt. Low (for me) because I went to bed early (for me—10:30pm) so was only awake about 9ish hours yesterday.

Woke up at 4am starving. Couldn’t get back to sleep and have been up since.

Like, for some people 1850 calories is a binge day. Some people don’t even eat that much on Christmas or Thanksgiving, or so it seems.

For me, 1850 calories is, “let me tally up what I’ve eaten in LoseIt so I can determine whether or not I need to take a sleeping pill to sleep through the night.” Yes, I did. And it got me 5 hours of sleep, so I’ll count that as effective.

But then I’ll start reading the blog of someone who’s eating 1200 calories day in day out and it’s like how do you do that? Aren’t you hungry? If so why do you have to be hungry all the time and I don’t? Am I crazy to eat/want this much food? Why do I get to eat so much?

Okay here are my answers for myself (aka why I “get” to eat 2500 calories/day):

  1. I’m not trying to lose weight
  2. I’m not trying to maintain an unnaturally low weight (I’m ~140)
  3. I’m tall (5’8) and pretty muscular so I need more food than a smaller girl
  4. And I’m young which makes my BMR higher
  5. I’ve made my metabolism pretty fast. I can literally feel my stomach burning through food.
  6. 2500 calories matches my daily calorie needs based on BMR (2300-2575) so it’s probably accurate
  7. I eat a balanced macronutrient ratio composed primarily of lean meats and proteins, fruits, vegetables, and healthy fat. Almost no starch. It’s not just 2500 calories of crap.
  8. 2500 is an average. I include alcohol and everything else in that. Most people eat more than they think because they don’t average—if you eat 1200 calories Monday through Friday and 3000 Saturday and Sunday including alcohol then you’re actually averaging 1700 cal/day, not 1200.
  9. The blog world is not the real world. Need to keep reminding myself of that!
  10. But within the blog world, the girls with bodies with bodies that I want eat pretty much like I do. 

Of all those points, #10 is probably the biggest reason I eat like I do. When I first starting lifting and reading the blogs of girls who lifted, I would see these girls who were 5’2 and 115 lbs eating 2400-2500 calories a day. I started to think “if they can eat that much and they’re still way tinier than me, why can’t I?” So I did. I had never heard of BMR and had no clue how to calculate how many calories my body actually needed. I sort of thought it was some magical property of weight lifting that let people eat that much. Now that I know how to do the math, I can see it’s right on track and makes sense, it’s not just magic.

And let’s be honest: when I’m reading through the archives of a blogger who attempts to eat 1100 calories a day and a year later still hasn’t lost any weight, why would I want to model myself after that person? I’m not trying to be mean, just giving myself a reality check because it’s easy to get caught up in the mindset of “well they do that so I should be too.” My philosophy has always been don’t follow the nutrition/exercise advice of someone that I wouldn’t trade bodies with, and overall the people I see who are successful and have a healthy attitude and life balance eat. Not starve. 

My point is…well I don’t really have a point, just me rambling. I’ve been up since 4am (as I said) lying in bed reading blogs and listening to the rain. About an hour ago I ate breakfast (3 whole eggs scrambled with mushrooms, spinach, tomato, avocado, and feta cheese) and now I’m thinking about 2nd breakfast—probs an apple and PB as I’m out of banana to make smoothies and the Royal Farms below my apartment didn’t have any when I ventured out in the rain at 7am (sad!) Normally I hate the rain but I’m okay with it today since it’s a) not cold just nice spring rain and b) it will help me be productive (laundry, cleaning, finishing up econ project do today). 

Peace out/Happy Monday!

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