Processed food is generally considered less healthy than foods that are closer to their natural or original state. This is because processing often tends to remove nutrients from food and add calories and sodium. In snack foods, for instance, additional calories often come from sugar, oils, and trans fats. In contrast, foods that have undergone little or no processing retain most of their original nutrients and have few if any added calories. Not all processed food is necessarily unhealthy, but many nutritionists recommend choosing foods that have been lightly or not at all processed.
Although many foods undergo some processing, processed food usually refers to snack foods, refined grains, and fast foods like frozen dinners. Many of these foods have added sodium, which can cause high blood pressure. Trans fat, which is used to keep foods from spoiling as quickly, can raise the bad LDL cholesterol and lower levels of good HDL cholesterol. The sugars in snacks and sweets are simply extra calories and can lead to weight gain in some people. These effects are associated with chronic health conditions like type 2 diabetes and cardiovascular disease.
One way in which processed food can be unhealthy happens when it replaces fresh fruits and vegetables and whole grains. Regularly eating fresh produce and whole grains has been connected to reduced risk of many chronic diseases. Unlike processed food, fresh produce is unchanged from the state in which it was harvested. Light processing of these foods, such as freezing and canning, often has a minimal effect on their nutrients. Still, canned vegetables often have added sodium, and canned fruits may have added sugars when packed in syrup.
Refined grain products are an example of processed foods that are considered less healthy than their unprocessed counterparts. Whole grains retain more vitamins and minerals as well as fiber, which are lost in foods such as white breads and pasta and snack foods such as pretzels or cookies. For instance, whole grains are much better sources of the minerals manganese and magnesium and are better sources of B vitamins. The fiber in whole grains is thought to make a person feel fuller, slow digestion, and have a more positive effect on blood sugar levels.
How someone defines processed food is also a factor in determining how healthy it may be. For instance, virtually all dairy foods are processed to some degree, but most are considered healthy in moderation. Using available health information can help a person avoid the least healthy processed foods. Nutrition labels indicate total calories, while ingredient lists will show added fats, sugars, and sodium. In the United States, whole grain foods will list the whole grain as the primary ingredient.
