A healthy diet is one that provides adequate levels of vitamins, minerals, protein, carbohydrate and healthy fats from a variety of foods. An unhealthy diet, in contrast, is one that contains too much saturated and trans fats, cholesterol, sodium, added sugars and processed ingredients or contains too few nutrients. Unhealthy diets result in a poor nutrient-to-calorie ratio, which can lead to weight gain and malnutrition as well as related health problems.
A healthy diet provides the nutrition your body needs to grow, maintain itself and function properly. A variety of fresh, whole foods serve as an abundant source of nutrients. However, the typical American diet often lacks adequate levels of key nutrients such as potassium, dietary fiber, calcium and vitamin D. Over time, failing to get enough calcium can cause bone loss, low levels of vitamin D can cause bone weakness and not getting the recommended levels of potassium can lead to fatigue and muscle weakness. Fiber helps keep your colon healthy and reduces the risk of heart disease and diabetes.
A nutritious diet provides the nutrients that help your body ward off disease. Over time, a diet lacking in nutrients and high in fat, salt or sugar can result in the development of chronic conditions. Following an unhealthy diet increases your risk for cardiovascular disease, hypertension, diabetes, cancer and osteoporosis, according to the Dietary Guidelines for Americans 2010.
When it comes to preventing chronic disease, weight maintenance is of primary concern. Excess weight is one of the primary effects of an unhealthy diet. The Centers for Disease Control and Prevention defines overweight as having a body mass index, or BMI, of 25 or higher. Factors that often contribute to a high BMI include insufficient fruits, vegetables and whole grains; diets high in meat and fried foods; consistent intake of high-calorie beverages like soda; and not getting enough physical activity.
The Domino Effect
Once your BMI reaches 30 or above, you are considered obese, and more than 35 percent of adults in America fall into this category, according to the CDC. Obesity increases your risk of developing a host of health problems including heart disease, Type 2 diabetes, certain cancers, high blood pressure, high cholesterol, stroke, sleep apnea, diseases of the liver and gallbladder, osteoarthritis and gynecological problems including infertility.