17 'Healthy' Foods That Are Actually Ruining Your Diet

Popcorn itself is not a terrible snack at all, Maycock said. The problem is when they are laced with butter, which is almost always the case with popcorn at the movies and many versions you see at the store. With the butter come trans fats, which have been linked to higher risk of developing heart disease, stroke, and diabetes.

Many companies process their products to remove the fat, but the problem is that much of the flavor is lost, too — so they add salt, artificial sweeteners, or sugar instead, Maher said. Flour and other thickeners, which can add calories, are often added as well. Read the labels. If you see a lot of sugar and additives, put the product down and walk away. Also walk away if you think of buying any of these foods and drinks that are only believed to be healthy.