Although a well-balanced nutritious diet is essential to weight loss, it will NOT give you the tone and shape you are after. In order to lose weight efficiently you need to monitor the amount of calories that are coming in VS the calories that are going out.
Without a proper exercise regime, food alone won't give you the body you are looking for.
Exercising regularly is also amazing for your muscles and bones. Muscle strength declines as people age, but those who exercise regularly are shown to be stronger and leaner than those who don't. The truth is if you want to look FIT, you need to be fit. A good nutrition plan will fuel your body to perform at it's best, but it alone will not increase muscle tone and strength. Add to this the fact that exercise helps to manage and prevent a wide range of health diseases including heart attacks, stroke and diabetes - the benefits of exercise are hard to ignore.
"Abs might be made in the kitchen, but bums are made in the gym"