Stop eating bread (yes, pizza counts as bread. beer counts as bread. stop it). Stop drinking calories unless you're exercising for 2+ hours at once (yes, fruit juice is bad for you. stop it).

The practice of making "processed foods" is essentially just cramming carbs and salt into everything and making it as highly concentrated as possible. Much processed food (read: basically anything pre-packaged in a wrapper) is more like a high calorie MRE food brick instead of something you should be combining with other foodstuffs.

We know how food interacts with human bodies. Water doesn't cause fat growth. Dietary fat doesn't cause fat growth (the chemical 'fat' isn't human fat tissue, so drinking a gallon of olive oil won't increase your fat stores). High glycemic sugars cause fat growth in non-glycogen depleted bags of bones. Turns out we can stop getting obese just by not eating things causing obesity.