Eating less processed foods is going to give you more energy and help you maintain a healthy weight. The more nutrient dense foods you consume the less high-calorie, low nutrion foods you will eat. Go ahead and eat some pizza...can you make the pizza at home using high quality whole foods rather than purchasing a frozen or fast food pizza? Focus on the quality of the ingredients and putting high-nutrition foods into your meals rather than food-like products.
Your Mission: Go through your pantry and start reading some labels.
-Are there five ingredients or less?
-Can I pronounce each of the ingredients?
-Would my grandmother recognize each ingredient?
-Can I find these ingredients in my kitchen?
If you answered "no" to any of these questions, you have a processed item. For a better choice, see if you can find a similar item that meets the above criteria.