As someone who recently embarked on a restricted-calorie diet, I can say that I'm not inclined to live longer in the sense of past the average life-span. I'm more inclined to have a higher quality of life and live long enough to see my child into his adulthood.

That said, outside of weightloss and increased energy and stamina, I have noticed a few things about a reduced-calorie diet (and I'm talking 1000 calories or less most days):

1) I don't think about food as anything but fuel. I no longer think of it as a way to be social, to pass the time, or to be happy.

2) While it's possible to eat 1000 calories of calorie dense food with almost no other nutrition (sugar), I find that hunger demands I eat things that have more mass with less calories (vegetables and some proteins).

3) My day no longer revolves around eating. Pretty simple, but previously, I would be very concerned with what I had eaten the day before and might eat tomorrow. Outside of the measurements I'm keeping about caloric intake, I seldom think about food.

4) I'm saving money. I used to eat out a lot. Eating out, except for maybe a salad, makes it hard to reduce caloric intake. Now, I eat at home on the pound-for-pound cheaper food we can get at the farmer's market or grocery store.