What Happens When You Don't Eat Healthfully?

When you don't give your body the proper nutrients, it's unable to function at its best. An unhealthy diet not only deprives you of the nutrients required for energy and vitality, it also introduces unhealthy substances such as trans fat, as well as high levels of saturated fat and sugar. The combination of the two can contribute to chronic diseases, compromised mental health and obesity.

An unhealthy diet is a major risk factor for having overweight or obesity. Unhealthy diets are often energy-dense, which means they are much higher in calories than nutrient-dense diets that include fruits, vegetables and other fiber-rich foods. When you consume more calories than you burn, the extra calories are stored as body fat. Obesity is a major risk factor for many chronic diseases, including cancer, cardiovascular disease, hypertension and Type 2 diabetes.

Diets high in unhealthy substances significantly increase the risk for many chronic diseases. Trans fat, for example, is an artificial saturated fat present in many fried foods, baked goods and packaged junk food. This dangerous fat can increase bad cholesterol while simultaneously decreasing good cholesterol, notes the Centers for Disease Control and Prevention. This artery-clogging effect is strongly linked to heart disease. According to the CDC, trans fats alone are responsible for between 10,000 and 20,000 heart attacks per year in the U.S. According to a 2002 statement published by the American Heart Association in the journal "Circulation," diets high in sugar are also strongly connected to heart disease, diabetes and nutritional deficiency.

When your diet is filled with unhealthy foods, it leaves less room for the nutritious foods that provide the vitamins and minerals your body requires. Without these nutrients, your risk for nutritional deficiencies increases. A 2005 paper published in "Molecular Aspects of Medicine" noted that vitamin and mineral deficiencies are a contributing factor to DNA damage and accelerated aging. The authors contend that an optimum intake of nutrients could "tune up metabolism and give a marked increase in health."

An unhealthy diet can also negatively affect mental health, as noted by a study published in 2013 in the journal "Social Psychiatry and Psychiatric Epidemiology." According to the article, there is an association between unhealthy diets and mental health problems, including depression, in adolescents.

According to a 2009 World Health Organization report, 80 percent of all cases of premature heart disease and Type 2 diabetes and 40 percent of all cancers can be prevented by simple lifestyle choices that include following a healthy diet, engaging in sufficient physical activity, and avoiding tobacco products. According to the Dietary Guidelines for Americans 2010, you can create a healthy diet simply by consuming wholesome foods, such as fruits, vegetables, whole grains, fish, nuts and seeds, and by eliminating processed foods, such as refined carbohydrates, prepackaged and fast foods, baked goods and any other foods high in sodium, trans fat, saturated fat or sugar.