Risks of Losing Too Much Weight Too Quickly

If you're overweight, you may feel eager to shed those excess pounds as quickly as possible. While rapid weight loss sounds good, there are reasons to avoid losing too much too quickly. The consensus is that slow and steady wins the race. Losing 1 to 2 pounds per week is a common recommendation. Losing weight at a slow, steady pace reduces the risk of unwanted side effects and increases the likelihood that you'll be able to keep it off.

A healthy woman doing gentle yoga in the park. (Image: Berc/iStock/Getty Images)

Gallstones Can Form

Gallstones are one of the most common complications of rapid weight loss. You have a greater chance of developing gallstones if you lose 3 or more pounds a week than if you lose weight slowly, according to the Weight-Control Information Network. Gallstones are solid pebbles made of cholesterol that form in your gallbladder -- an organ that stores bile for fat digestion. Rapid weight loss may prevent the gallbladder from emptying properly or cause an imbalance in bile salts and cholesterol, causing gallstones to form.

It Could Damage Your Liver

Alcohol abuse isn't the only factor that puts you at risk of developing a fatty liver. Losing excess weight too quickly is a risk factor for nonalcoholic fatty liver. Although the exact mechanism is unclear, rapid changes in the level of fat in your blood may play a role, according to Dr. Mary Harding in an article for Patient.co.uk. The bottom line is: rapid weight loss of 4 or more pounds per week can end up damaging your liver, according to Harvard Medical School.

Your Metabolism Takes a Nosedive

Losing a lot of weight too rapidly kicks your body into survival mode, where it makes certain adaptations to slow energy use. The National Institutes of Health researchers witnessed this during an experiment with obese subjects who rapidly lost a large amount of weight. The study found participants experienced a highly significant decline in resting metabolic rate -- which refers to the amount of calories you burn at rest. The decrease was out of proportion to the amount of weight lost and persisted after participants reached their goal weight. Researchers concluded this significant decrease in metabolism can put you at risk for regaining weight. The study was published in "The Journal of Clinical Endocrinology & Metabolism," July 2012 edition.

Could Throw Fluid Balance Out of Whack

Maintaining the right balance of electrolytes is crucial to your health. At least initially, when you lose a significant amount of weight too quickly, much of it consists of water. Rapid fluid loss can disrupt the balance of minerals since the body excretes sodium in order to get rid of water. Your muscles, including your heart muscle, depend on the proper electrolyte balance. Electrolytes carry an electrical charge and play a role in helping your muscles contract and your heart beat properly.