A low-calorie diet is a diet that maintains calorie intake between 1200-1500 kcal for men and 1000-1200 kcal for women. Considering that women normally consume about 1800-2200 kcal of food daily and men consume 2000-2500 kcal daily, that's an average decrease in calorie intake of 600-1000 kcal. This amount is equivalent to at least one meal, and it is a method that is used widely by many people. Skipping a meal, setting a desired calorie intake and eating accordingly, and halving meal portions are ways of adhering to low-calorie diets.
However, continuing this type of diet, as with very low-calorie diets, can lead to side effects such as lack of energy, dizziness, hunger, and malnutrition. There's a high chance of regaining weight from the yo-yo effect with this method also.
The best way to diet is to decrease average consumption by 500 kcal. However, a balanced diet must be maintained. Ways to accomplish this are to avoid overeating during the weekends, avoid drinking too many alcoholic or sweetened beverages, or by cutting down on snacks. Substituting high-calorie foods with low-calorie foods should be effective in realizing good results. By reducing calorie intake by 500 kcal a day, monthly calorie intake is reduced by 15,000 kcal, resulting in a loss of about 2 kg a month. Experts recommend that, of the 500 kcal, 250 kcal should be taken out of meals, and the other 250 kcal be burned through exercise.
What is a Very Low-calorie Diet (VLCD)?
VLCD is a dieting method that reduces body weight by consuming 400-800 kcal a day, allowing a loss of 1-1.5 kg every week. Although it is advised that a person eat no less than 1200 kcal a day, the following are instances when it is advisable and not advisable to follow a VLCD.
VLCD is recommended for:
# People 30% overweight from the standard weight, or people with a body mass index greater than 30.
# People who have attempted a low-calorie diet but failed.
# People willing to visit the hospital every week or month to receive treatment for a year.
# Those who would sincerely like to change their lifestyle.
Not recommended for:
# Pregnant and nursing women.
# People older than age 65 or younger than age 18.
# Those with a prior diagnosis of gout, acute myocardial infarction, heart disorder, psychological problems, drug addiction/use, diabetes, electrolyte disorder, or angina.
Important Points for VLCD:
A proper VLCD minimizes nitrogen imbalance, decreases fat, and motivates the patient to continue dieting. Generally, formulas that substitute meals are used in VLCD. The formulas used in obesity clinics are usually those approved by the FDA, and of them, 3 are widely accepted by most governments as safe. The formulas are mostly protein-based, or a combination of protein and carbohydrates. Depending on the patient, these formulas take the place of 1, 2, or all 3 meals.
However, this method is only used to lose a large amount of weight in a short time, and tends to lose its effect on weight loss if continued for a prolonged period of time. Almost always, weight is regained after a VLCD, so it is important to learn and be prepared for a change in behavioral, lifestyle, and eating habits. A VLCD lasts for about 12-16 weeks (3-4 months). Heavier people have more body fat, and can carry out a VLCD for a longer period. Eating normal food after a VLCD should be done gradually over a 3- to 6-week period.
For example, when using the VLCD method to lose a target weight of 23 kg, men lose about 2 kg/week, and women lose about 1.5 kg/week. Generally, the recommended speed of weight loss during a VLCD should not exceed 1-2 kg/week. Faster weight loss can cause extensive damage to fat cells and protein throughout the body. Patients advised to lose more than 2 kg a week, require careful supervision to ensure a balanced and safe VLCD and that activities are not too strenuous. If necessary, a day's calorie intake is added to slow down the speed at which body weight is decreasing.
About 50% of VLCD participants drop out before the program ends, and about 30% of participants who complete the program maintain their weight for at least 18 months. Many regain their weight after completing the program because they do not establish appropriate lifestyle and eating habits. Because a VLCD can cause serious complications and side effects, it must be done under medical supervision, along with a balanced diet, exercise, a healthy lifestyle, and a program that can keep lost weight off.