Over New Year's, I decided to challenge myself: lose as much body fat as I can and build up muscle.

This idea started years ago when I realized I must be one of the few boyfriends who couldn't carry his girlfriend. The idea came to fruition when three things happened over the winter break:

• My siblings and I got Wii Fit for our mom, to help keep her healthy. Since then, she's played it nearly every day, and I also played it nearly every day. I began to realize that to achieve a goal such as weight loss or physical fitness, there must be a process or a scaffold that makes accomplishing that goal (1) easy to do, and (2) fun.
• My mom stuffed me with delicious Christmas food, and I realized that I didn't know what exactly I was putting into my body.
• There was a New Year's sale for fitness software for my Windows Mobile phone.

I splurged and purchased VidaOne's MySportTrainer and MyPersonalDiet, and bought some measuring cups, a body scale and a food scale from Ikea, and 10 cases of Slim Fast Optima shakes ("meal replacements" — good only if you complement it with something to really fill your stomach, like celery sticks). I also got 10 Minute Trainer and some other exercise DVD's from my girlfriend. I think most of my fun comes from keeping track of everything on my phone.

In MyPersonalDiet, I enter the foods I've eaten, and it keeps track of fat, protein, and caloric intake. It comes with a very large searchable database of foods which is convenient when I'm on the go, but I've been adding the nutrition info from restaurants and supermarket foods as well. This process makes me much more conscious of the foods I eat. Sometimes I refuse to eat a food b/c I don't even know how to enter it into my Treo phone — for example, I now refuse to snack on popcorn unless I can measure out the exact quantity.

In MySportTrainer, I enter in all of my physical activity for the day, including walking, bicycling, and any exercise DVD's I do. For exercise DVD's, I measure the number of calories with a Polar heart rate monitor, then estimate by the number of minutes of exercise I do. The program then keeps track of the calories I've lost.

As long as I lose a net number of calories per day, I'm fine. Below is my 30-day history of this experiment. You can see there were a few days I lost control and took in more calories (around exam time and an Indian buffet free-for-all), but overall I think I've been pretty successful.

I've lost quite a few pounds since. I feel very good! Not as drastic as The Biggest Loser, but I've never done anything like this before and it feels empowering. :) I wonder how I can stay fit like this throughout my third year of medical school. Maybe I should get a pedometer to track all of my steps through the hospital.