Undergraduate / Hard work was preferable to the expense of neglected morals and sore back - Ethical dilemma QB essay [9]

Evaluate a significant experience, achievement, risk you have taken, or ethical dilemma you have faced and its impact on you. (500 word limit) *
(scholarship/admission essay)

An updated version...I'm under by about 30 words. Should I clarify anything?

Halfway through my busy shift, I reached down my back to massage the knot out with rough fingertips. I wasn't looking forward to the heap of dishes on the counter and I wondered why I ever took this job. After all, I was paid barely above minimum wage, I wouldn't be home till after 10 PM, and I'd be dog-tired. Then a waitress came into the kitchen with another armload of plates and smiled at me. "We just sat the last reservation, hang in there." I remembered one of the reasons I worked here. I initially took the dish washing job at Roma's, and the ones before it, because I didn't want to work at McDonald's. It wasn't a matter of pride and certainly not money; it was a matter of principle.

In seventh grade we watched the movie Super Size Me in health class. It's about a man who ate McDonald's for three meals a day for a month; he gained almost 25 pounds, got heart palpitations, mood swings, and liver damage. He also showed that their french fries contained so much preservatives that they don't rot...ever. I never willingly ate fast food again. I was a little overweight at that time and when I stopped eating fast food I got a little trimmer. I became conscious of my health and ate healthier and exercised more. I kept this up as I started high school. I lost more weight, gained more self confidence, and just enjoyed school more. I found after school activities I wanted to participate in but I couldn't because I had to ride the bus home. My mom agreed to help me pay for a car, but first I needed a job.

I saw McDonald's sign "Now hiring". But I knew I'd feel dishonorable smiling and serving people food that was so unhealthy. I applied at a few other places and again noticed McDonald's sign. This time reading "Now hiring $9 an hour". With minimum wage at $7, it was quite appealing. I talked to my mom about it and she supported whatever I did, so long as I earned enough for car payments and gas.

I thought it over, did the math, and found that a minimum wage job would be enough for a loan, insurance, and gas if I worked more than 17 hours a week. I had jobs at Safeway, Sanford's Grub and Pub, and an Italian restaurant, Roma's. Between each job, McDonald's was lurking with its alluring pay. I stuck to my decision and kept dish washing despite being diagnosed with mild scoliosis. Working at each of those places was definitely a strain on my back and eventually I had to quit Roma's as a result. I did learn that hard, honest work was preferable to the expense of neglected morals, even with a sore back and less pay.

This is a very important essay for me and any criticism would be appreciated.
I'm unsure if this clearly depicts the situation and its impact enough.