Clearly define all the reasons you want to lose weight and write them down. This will help you stay committed and motivated to reach your weight loss goals. Try to read through them daily and use them as a reminder when tempted to stray from your weight loss plans. Your reasons could include preventing diabetes, keeping up with grandchildren, looking your best for an event, improving your self-confidence or fitting into a certain pair of jeans. Many people start losing weight because their doctor suggested it, but research shows that people are more successful if their weight loss motivation comes from within.