How can I start eating a healthier diet?

A healthy diet includes eating a variety of foods from the basic food groups: protein, such as meat, eggs, and legumes; dairy; fruits and vegetables; grains, such as breads and pasta; and fats and sweets. As simple as this sounds, it’s not always easy to get the nutrition you need. You may eat more of your favorite foods from only one food group, and as a result, avoid others. Or perhaps you opt for convenience over quality when you are hungry.

A healthy diet requires some planning and purpose and an effort to include a variety of foods in your meals. If you look closely at how you eat, you might find you aren't getting enough nutrients because you don't get the recommended number of servings from each food group.

So, not only is it important to pay attention to what you eat but also to what you are missing from your diet. To accomplish this, keep a food diary of everything you eat and drink for 1 week. Pay attention to serving sizes, and check to see if you are eating a variety of foods from each of the food groups. You don't need to meet the minimum number every day, but try to get the recommended intake on average over a week. You might find that making a few small changes will ensure that you're eating a healthy, balanced diet. Or, you may find that you are missing many important nutrients.

http://my.webmd.com/hw/diet_and_nutrition/aa158942.asp?z=1671_00000_0000_tn_04