You know junk food isn't good for you, but it's hard to avoid because food companies have mastered the perfect taste sensation, largely a blend of salt, sugar and fat, to keep you coming back for more. By definition, junk food is food with minimal essential nutrients and a lot of fat, sugar and salt, such as potato chips, candy and soda. Enjoying a handful of potato chips now and then isn't going to break your diet, but overindulging in junk food can have negative physical and emotional consequences.
Junk foods are high-energy-dense foods because they contain a lot of calories, mostly from fat and sugar, but offer few nutritional benefits. When you fill yourself up with empty calories, you may be left craving more. A study published in 2012 in "The American Journal of Clinical Nutrition" found that regularly consuming high-energy-dense junk food decreases sensory-specific satiety, causing you to eat more of that food. If you overeat consistently, especially junk food, this can lead to weight gain and obesity.
Junk food tends to be high in saturated fat and cholesterol. According to the American Heart Association, saturated fat and cholesterol raise your cholesterol levels, putting you at risk for heart disease and stroke. The excess sodium that's found in most processed food can raise your blood pressure as well as increase the chance that you will develop heart disease.
Type 2 Diabetes
Your body uses insulin to move blood sugar from digested food into cells, where it is stored until your body needs it. The refined carbohydrates, or added sugars, in junk food cause spikes and then dips in your blood sugar levels. This leads to insulin resistance and hyperglycemia, where sugar doesn't get stored, but rather stays in your bloodstream. Over time, you can develop Type 2 diabetes, a condition that puts you at risk for a number of other health complications, according to MedlinePlus.
When you eat too much junk food, you may suffer from deficiencies in vitamins and minerals. High-energy-dense foods often lack protein; calcium; iron; vitamins A, C, D and E; B vitamins; potassium; zinc; and monounsaturated fats. A deficiency in any of these nutrients compromises your immune system and puts you at risk for illness and infection, according to Dr. Victoria J. Drake, a research associate at the Linus Pauling Institute. If you're nutritionally deficient, your body also can't make the neurotransmitter serotonin, which may leave you with feelings of anxiety, depression and irritability.
- Why Humans Like Junk Food; Steven Witherly
- KidsHealth: Junk Food
- The American Journal of Clinical Nutrition: Long-Term Consumption of High Energy-Dense Snack Foods on Sensory-Specific Satiety and Intake
- American Heart Association: Saturated Fats
- Centers for Disease Control and Prevention: Most Americans Should Consume Less Sodium
- MedlinePlus: Type 2 Diabetes
- The Guardian: Poor Diet Link to Rising Cases of Depression
- The Medical Journal of Australia: Paradoxical Nutritional Deficiency in Overweight and Obesity: The Importance of Nutrient Density
- Linus Pauling Institute at Oregon State University: Nutrition and Immunity, Part I