Dumbbells will lift your self-esteem as they help you in your quest to change your body and shift your body composition from fat cells to lean muscle. When you are able to see changes in the body you will feel better about yourself and so although buying a pair of dumbbells will not create the change in your body, using them will.
Another benefit of weight bearing exercise is how it positively affects bone density. By strengthening your muscles you are helping to save off the bone loss associated with age and lack of physical activity. Training with dumbbells will also increase your metabolism so that even at rest you are burning extra calories. Become the calorie machine you are meant to be by adding muscle to your frame.