Certain processed foods have small amounts of approved chemicals added to increase their safety, shelf-life, appearance, texture, or taste. In small amounts, preservatives and additives are not harmful and are infinitely preferable to mould and rancidity. Low-fat foods are healthier, but take the joy out of eating. This needn't be so. Breads, cereals, fruits, and vegetables can taste great, and they're almost invariably low in fat.
Lean meat is readily available as are low-fat milk and milk products.