This is a topic that I get asked a lot personally. I hope my answer can shed some light on the subject and help you along the way!
The biggest flaw in the western diet is something called "convenience". Most people typically don't have the time to prepare food fresh, which leaves a gap in their day to intake nutrients. Pre packaged foods contain large amounts of sodium and are "bulked" with excess calories from fat mainly as it is the cheapest macro-nutrient to add for its value (9calories per gram of fat as opposed to carbohydrates and protein both at 4calories per gram)
Some of the tips that I give during consultations are .. ALWAYS read nutrition labels and read through the ingredient list, swap out drinks that contain sugar for water, be aware of the amount of salt that foods contain (check on the labels) and most importantly be aware of the different foods groups, use single ingredient foods (Carrot, fresh meat, rice etc.) and add salt to enhance flavour if you wish. Knowledge is key when it comes to nutrition!
The intake of sodium and fat is widely misunderstood by the public but that is a topic for another day! Don't be afraid of salt or saturated fat as they are essential and needed, the keyword here is moderation. Moderate the amount of "bad" food and you'll be fine.
I hope this gave you some background and helped you out.