I'm tall, and the 195lbs I usually weighed always seemed to be stretched pretty thin over my 6'3" frame. Working in a bakery and playing basketball and tennis with friends went a long way toward keeping me relatively trim in my early twenties.
I made two choices in my mid-twenties that negatively affected my health. I chose to pursue a PhD in History and I chose to eat and drink A LOT OF CRAP while I did. I sat in front of a computer and endless stack of papers five or six days a week, guzzling coffees laced with sugar and cream, and eating quick junk because I didn't think I had the time to make something good to eat (apparently I had never heard of the apple or orange at this point). By the time I was 26, I weighed over 230lbs and could barely squeeze into size 38 jeans. In every mirror I saw a bloated pig. I ate and drank garbage. I felt like garbage as a result. I reached my tipping point.
On a trip home to Newfoundland the following May, I resolved to do three things: go for a brisk half hour walk every day of the week; drink a lot more water; and eat more fresh fruit and vegetables.
I returned to Halifax three months later. I weighed 205lbs, my pants and shorts had become baggy, and I had heaps of energy. I pushed myself to keep going, to keep improving. I switched to whole grain rices and breads when I did eat them, and completely banished sugar and cream from my teas and coffees (I still do like an occasional coffee or tea, I admit). My walks turned into occasional jogs (depending on how my ankles and knee felt), and by the following spring I was doing pushups, crunches and squats for the first time. A year after being utterly disgusted with myself, I weighed 180 pounds and felt great.
I've kept it up in the five years since. I weigh a few pounds more (added a little bit of muscle), and have developed my own simple cardio, strength, and stretching routines. I am stronger and more flexible than I've ever been (my knee doesn't even bother me anymore). Sometimes I wish I'd been in this kind of shape when I played basketball in high school because I probably would've been dunking all over the place!
Changing how I ate changed everything. Dumping the processed foods and sugar-rush sweets in exchange for fruits, vegetables, nuts, yogurt, eggs, and lean meat has been the real catalyst. It triggered my initial fat loss and provided the stores of energy I needed to tackle the exercise routines I developed for myself. I used to treat eating as an indulgence. Now I treat it as fuel that enables me to become healthier and stronger.
When a friend asked me about this a couple of years ago, I explained it to him like this:
If a person buys a nice car that they wish to maintain at an optimal level, they'll need to put only the best fuels and fluids into its system. Your body is your car, but it's the only one you're ever gonna get. Treat your body the way those people treat their cars and you'll do alright.
My friend got the message. He eats good now and participates in a wide range of fitness classes every week. More importantly, he looks good and feels great.
Don't eat to feel full. Eat to feel better.