Is It Bad to Lose Weight Too Quickly?

According to many experts, losing 1–2 pounds (0.45–0.9 kg) per week is a healthy and safe rate (1, 2Trusted Source, 3Trusted Source).

Losing more than that is considered too fast and could put you at risk of many health problems, including muscle loss, gallstones, nutritional deficiencies and a drop in metabolism (4, 6Trusted Source, 7Trusted Source, 8).

The most common ways that people try to lose weight fast are by exercising a lot, and by following a”crash diet” or a very low-calorie diet of fewer than 800 calories per day.

People often prefer the option of eating a very low-calorie diet, since it is often easier to lose weight through diet than exercise (9Trusted Source).

However, if you’re just starting a diet or exercise plan, then you may lose much more than 2 pounds (0.9 kg) in your first week.

For this initial period, fast weight loss is perfectly normal. The weight you lose during this time is commonly called “water weight.”

When you consume fewer calories than your body burns, your body starts dipping into its stores of energy, known as glycogen. The glycogen in your body is bound to water, so when you’re burning glycogen for fuel, the body also releases that water (10Trusted Source, 11Trusted Source).

This is why you might experience a major drop in weight during your first week. Once your body uses up its glycogen stores, your weight loss should stabilize at 1–2 pounds (0.45–0.9 kg) per week.

SUMMARY:According to experts, losing 1–2 pounds (0.45–0.9 kg) per week is a healthy and safe rate, while losing more than this is considered too fast. However, you may lose more than that during your first week of an exercise or diet plan.