What if I only eat 300-500 calories a day for a few months?

Consuming 500 calories a day is not a healthy diet. Normally, eating anything below 1200 calories per day will make your body assume there's a food shortage. The end result will cause your body to go into what is known as "Starvation Mode". During this mode, your metabolism will slow down and try to conserve energy. A slow metabolism will make it difficult for your body to lose weight. It's recommended to consume around 1200 - 1500 calories per day in an effort to lose weight.

The idea of a low-calorie diet might tempt you because it seems like the quickest, way to lose weight. It certainly isn't easy, but it will get results. However, many negative side effects come along with restricting your calorie intake below 1,200. Some side effects are minor and will pass with a good meal, but some are more serious and can land you in the hospital. Do not attempt a low-calorie diet unless you are under the strict supervision of your doctor.

Possible side effects of very-low-calorie diets include nausea, fatigue, diarrhea, intolerance to cold, menstrual irregularities and hair loss. If the meal-replacement products used in very-low-calorie diets do not contain sufficient amounts of dietary fiber, these diets can cause constipation to occur. Rapid weight loss can also cause gallstones in people who are susceptible to them.

More serious potential consequences include heart arrhythmia, stroke and brain hemorrhage. Pregnant women who follow these diets are more likely to have children with birth defects. If you consume too much liquid and not enough protein, you could also develop hyponatremia, or low blood sodium, which can cause dizziness, fatigue, confusion, coma and death. These diets can also cause nutrient deficiencies if not carefully planned.

Very-low-calorie diets can lead to fast weight loss, with obese patients losing approximately 3 to 5 pounds per week. However, a significant amount of early weight loss is water weight, and later weight loss includes approximately 30 percent muscle loss or more. Since many people have difficulty maintaining this weight loss, they often end up with higher percentages of body fat and less muscle after regaining lost weight. This sets them up for more weight gain and more health problems.

The greatest dangers associated with a 500-calorie diet relate to vitamin and mineral deficiencies. Vitamin and mineral deficiencies can lead to many health problems. In fact, most people cannot meet their vitamin and mineral requirements if they eat less than 1200 calories per day.

Low iron intake can lead to anemia, while chronic low intake of calcium and vitamin D can lead to osteoporosis later in life. If you don’t get enough of the vitamin niacin, found in tuna and dates, you could be at risk for heart attack due to clogged arteries. Always consider the full nutritional makeup of the foods you eat, not just their calories.

Low-calorie diets force your body to take energy from other sources. You are more likely to burn muscle than fat because your body needs protein. This lowers your metabolic rate and makes it more difficult to lose weight. You are also not likely to stay on this type of eating plan for long, and you will eventually go back to your normal eating patterns. All the weight will come back. Furthermore, the electrolyte imbalances will cause your body to leach calcium from your bones, potentially weakening them and leading to osteoporosis.