DIET vs LIFESTYLE

DIET

The goal is self-limiting.
When you get to your goal weight, you stop the diet

LIFESTYLE

The goal is open-ended.
Weight management becomes part of your daily life, with strategies that vary as circumstances, priorities, and needs change.
DIET
A diet is a surface level change.
It involves simple changes in behaviors you are already doing (or not doing). You take in fewer calories from food and (maybe) expend more calories on activity. Foods are "good" or "bad" based on calorie content.

LIFESTYLE
Lifestyle changes are made on many levels.
In addition to healthy changes in your relationship with food and exercise, you will challenge the basic attitudes, beliefs, thoughts and feelings that made you overweight (and unhappy) to begin with.

DIET
Progress and success are measured by the scale.
Anything that results in weight loss is considered acceptable, even if it poses potential problems or risks. Failure to lose weight as fast as desired is very upsetting, and the process feels like a constant battle. High stress is constant.

LIFESTYLE

Progress and success are measured in terms of satisfaction & quality of life.
Weight loss and maintenance continue to be important, but are put in perspective as one way you can move towards larger, more rewarding goals. Daily ups and downs become much less stressful.

DIET
Results don't last.
Even if you manage to stick with all the unpleasantness of a diet long enough to reach your weight goal, your odds of keeping it off permanently are less than one in twenty.

LIFESTYLE
Results are lasting.
Your lifestyle change is an open-ended, ongoing process with goals that continue to expand and grow. There is no reason to go back to the habits that got you overweight in the first place.

found this article on sparkpeople.com