This article may help you to be aware that what you think is healthy might be opposite. Here is the list:
Pasta: The typical fare you get at the grocery store is most often plain white flour with water and eggs; this means no minerals, vitamins, fiber, or anything else your body needs, so you are eating a bowl of empty calories.

White Bread: Put simply this is pasta, baked into bread, same ingredients.

Soup Mix: This can be seen as an artificial mixture of salt and preservatives, major contributors to heart disease.

Ketchup: A spoonful of ketchup can be synonymous with a spoonful of sugar with a pinch of salt (by pinch we mean less salt than sugar, but still enough to be harmful to your health)

Diet Soda: “Diet” Sodas are even worse than the sugar-filled versions, thanks to the artificial sweeteners they use, like Aspartame, which can increase risk of certain kinds of cancer, remember unless it is naturally fat-free or light think chemical crap storm!

Soy Sauce: It has high amounts of salt and there are often chemicals known to increase risk for certain types of cancer.

Salty Peanuts: Nuts themselves are healthy and filled with healthy fat, fiber, and minerals we need, but the majority of peanuts sold as snacks come laden with huge amounts of salt, roasted, and often coated in unhealthy fats or sugar.

Fruit juice: Commercial fruit juice is often ‘flavor-enhanced’ by adding sugar, and the pulp has been removed, taking away the essential fiber (a good counterbalance to all the natural sugar contained in the fruit)
Source: http://listverse.com/2012/05/18/10-unhealthy-foods-you-think-are-healthy/

Whilst the above post is worth a mention, Discovery have posted a far more in-depth and relevant infographic on unhealthy healthy foods. Check it out -
http://www.discovery.uk.com/blog/10-things-you-didnt-know-were-killing-you/