Healthy eating means choosing foods that are good for you and learning portion control.  Poor diet and physical inactivity are linked to many serious diseases like cardiovascular disease, Type II diabetes, hypertension and some cancers.  Also, a poor diet and physical inactivity can cause an energy imbalance, meaning that you are consuming more calories than you are using.  This can lead to weight gain and obesity.  According to the USDA's Dietary Guidelines, a healthy diet emphasizes fruits, vegetables, whole grains, and fat-free or low-fat milk products.  One's diet should also include lean meats, poultry, fish, eggs and nuts.  A healthy diet is low in saturated fats, trans fats, cholesterol, salt and added sugars.  The bulk of your diet should come from vegetables, fruits and whole grains.  Refer to the Food Pyramid for more information.  It is important to know not only what kind of foods you should eat, but also the suggested serving size of everything you consume.  Not knowing serving sizes will lead to overeating and weight gain!  Read nutrition labels to learn serving sizes, and realize if you eat more than the recommended serving size, you are consuming more calories and fat than if you were only to eat the suggested amount.  A simple rule of thumb is that 1 portion of food should be able to fit in the palm of your hand!