Calories are to your body what gasoline is to a car -- fuel. Calories are important to keep your organs functioning, muscles moving and metabolism blazing. If you eat too many calories, then you may increase your risk of certain health conditions such as obesity, diabetes and heart disease. If you eat too few calories, then you may increase your risk of certain other health conditions such as anorexia, anemia and bone loss.
One of the risks of not enough calories is that it puts your body into starvation mode. Starvation mode is when your metabolism slows down to preserve calories for important bodily functions, like breathing and circulation of blood. As a result, you may start to feel sluggish, experience trouble thinking, suffer from more colds and other health complications. Not enough calories may also impact your muscular strength and bone health, and may even cause organ failure.
It sounds counterintuitive, but it's true: When you cut too many calories out of your diet, your metabolism slows down, according to a study in the March 2006 issue of "Environmental Health and Preventive Medicine." When you inevitably stop the restrictive diet, you will gain weight again as your body adjusts to store whatever calories you do eat as fat. If weight loss is your goal, speak to your doctor about the diet plan that works best for you. Your doctor may recommend that you eat a healthy, well-balanced diet, keep a food journal, watch portion sizes and make smarter food choices. Being active will burn more calories than drastic dieting measures ever will.
If you're not getting enough calories, chances are you're not getting enough vitamins and minerals either. Nutritional deficiencies may cause a long list of health complications including, but not limited to, anemia, infertility, bone loss, poor dental health and decreased thyroid function. Your body needs vitamins and minerals, even fat and carbohydrates, to perform regular bodily functions. Without glucose, which comes from calories, you may suffer from depression or low blood sugar.
Another risk of not enough calories it that it may increase your risk of an eating disorder, such as anorexia. In general, those who suffer from anorexia have an altered view of their own body. The National Institute of Mental Health explains that they see themselves as heavy when they are actually underweight. Bulemia is an eating disorder in which you binge on food and then purge it through vomiting or other means. Eating disorders affect both men and women. Signs of an eating disorder include fear of gaining weight, extreme interest in the nutritional information of food, excessive exercising and poor self-esteem. If you or someone you know suffers from anorexia, or any other eating disorder, seek professional medical care immediately.