Severe calorie deficiency may be self-induced or the result of illness or deprivation; either cause may be a precursor to death. Only a few weeks without nourishment can move you from initial vitamin and mineral deficiencies to body-mass depletion and life-ending organ failures. Prolonged caloric restriction provides insufficient metabolic energy and robs the body of mass and stored nutrients. Some people at this stage require intravenous feeding. If you diet to extremes for longer than a week or two, you may be heading for starvation mode.
Too Little Food
You may be unable or unwilling to eat regular portions at regular meals, but this does not change your body’s persistent needs for carbohydrates, protein, fats, minerals and vitamins. Your mental and physical processes depend on adequate levels of these nutrients. An eating disorder, such as anorexia nervosa, or unsafe dieting methods can prompt you to cut so many calories that you deny yourself essential nutrition.
Too Few Calories
Even if you eat substantial food volume, you might still choose extremely low-calorie foods that do not fulfill your daily needs. According to the Merck Manual Home Health Handbook, your mineral and vitamin intake shrinks along with your calorie intake. Depending on your sex and body type, fewer than 1,000 calories a day may not be enough for you to live on. If you are skipping meals and cutting calories the rest of the time, you may be at risk for dangerously low caloric intake.
Too Few Nutrients
Low consumption of calories, vitamins and minerals makes you less likely to get enough protein, fat and carbohydrates, which your body uses for cellular energy and growth. When these nutrients are absent or inadequate, body stores are used to supply them, reducing first your fatty tissue and then moving on to muscle mass. Body fat insulates and protects your organs and musculoskeletal system, and your muscles enable breathing, circulation, digestion and mobility. Depleting your fat and muscle tissue can affect your mental and physical energy levels and abilities and propel you toward starvation.
When you lack the protein, vitamins and minerals to support blood cell production, your blood carries less oxygen to your muscles and organs. Breathing, heart contractions and digestive action slow down. This starvation mode prevents your body from fighting off infections and repairing tissue. Within 8 to 12 weeks of no nutritional input, you may suffer fatal diarrhea, bleeding, or heart, lung or liver failure.