Food that comes in a box, bag, or can, and can live on the shelf, not fridge. Processed food comes from the factory, not the field. It is loaded with salt, sugar, and fat; and is engineered to be addictive. Processed food causes people to eat 500 extra calories daily, and has likely caused the obesity epidemic.
Carbs (breads, pastas, cereal, rice, etc) with no fiber are just sugar - without the sweetness. Most people aren't aware that a bagel is just as bad as a pepsi, and corn flakes are as bad as jelly beans. Learn to read nutrition labels. Instead of low-fiber carbohydrates, eat whole grains.
The food industry sneaks sugar into everything, even "healthy" foods like yogurt, granola bars, and soy milk. Nutrition labels report added sugar separately from total sugar. Look out for it, and choose foods with little or none. Sugary drinks are lethal. The more you drink, the sooner you die. Water is the best option for thirst - or, if you must, a zero-calorie beverage.
Many of the cookies, cakes, peanut butters, margarines, and other such foods available in supermarkets have partially or fully hydrogenated oil. It clogs arteries. Don't eat it.
We don't all need to be vegan to be healthy, but by and large Americans need to eat less meat, poultry, dairy, and seafood. All groups that routinely live to 100 consume a plant-heavy or plant exclusive diet. For the sake of our bodies and our planet, we should all eat less animal food. If you do go completely vegan, make sure to take 500 mcg B12 daily!
Restaurant food is prepared to maximize flavor, often at the expense of health. Your body needs, and deserves, better. Let's stop enriching others at the expense of our health by eating at large chains like Dunkin Donuts, Chick-Fil-A, Texas Roadhouse, etc.