Weight loss requires you to reduce your total calorie intake to below what you burn. It would make sense then, that if you completely cut out calories consumed, you accelerate weight loss. However, quick weight loss is simply not this easy. Starving yourself may result in some immediate weight loss, but most of it will return once you begin eating regular food again.
Weight Loss Potential
The most weight a person can lose in either fat or muscle is ½ pound per day, says Joanne Larsen, RD. Any weight loss beyond this amount is water, but once you replace that water, the number on the scale goes back up. The body is reluctant to move fat out of storage to use during a fast because it needs it to keep you alive when it perceives it is starving, says Larsen. It breaks down muscle in the absence of fuel because, as the muscles become smaller, they work less and utilize less energy, allowing you to last longer on the stored supplies of fat. Larsen goes on to point out that less stored fat is lost on a diet consisting of 600 to 900 calories than on a low-calorie diet of 1,200 calories daily.
You need a minimum of 1,200 calories per day as a woman or 1,500 as a man to support nutrition for bodily functions like breathing, cellular repair, hormone production and pumping blood, says MedlinePlus. Starvation leaves no fuel for these basic bodily functions, let alone energy for daily tasks. Following a fast or starvation diet for several days can also cause nutritional deficiencies, dizziness, weakness, digestive distress, nausea, irritability, depression and fatigue. Undergoing a fast or starvation diet for too long can seriously compromise your health, and lead to organ failure and even death.
When you fast, your body slows down your metabolism in order to conserve energy and survive the perceived famine, explains MayoClinic.com. This happens within just a few days, notes Marc Hellerstein, MD, Ph.D. and professor of human nutrition at the University of California at Berkeley. When you do go back to eating, your body wants to store up for the next starvation period, meaning that you are likely to gain weight even if you consume fewer calories.
As it is unlikely that you put on your extra weight in only a few days, it is unrealistic to believe you can lose it that quickly. A slow rate of weight loss amounting to just one or two pounds per week is the most maintainable progression, says the Centers for Disease Control and Prevention. When you lose weight slowly, you can sustain the changes for the long term and not suffer from extreme feelings of deprivation. In addition, your body can adjust to small reductions in calorie intake without feeling like it is facing a life-threatening famine.
A weight loss plan emphasizing whole foods that are minimally processed is the best weight loss strategy, says the American Heart Association, Harvard School of Public Health and the CDC. Instead of cutting food out altogether, seek to create calorie deficit of between 500 and 1,000 calories. Utilize physical activity along with dietary measures to create this negative calorie balance.