According to many experts, losing 1–2 pounds (0.45–0.9 kg) per week is a healthy and safe rate (1, 2, 3 ). 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 , 6 , 7 , 8 ).
But many health care providers agree that a medical evaluation is called for if you lose more than 5% of your weight in 6 to 12 months, especially if you're an older adult. For example, a 5% weight loss in someone who is 160 pounds (72 kilograms) is 8 pounds (3.6 kilograms).
Rapid weight loss usually occurs from extreme calorie deprivation, for example, people who go from eating 3,000 to 1,200 calories a day, says Gans. Trouble is, our body recognizes this as a sign of limited food supply and goes into starvation mode.
Fast weight loss, such as losing 10 pounds in a week, is possible — but it's usually not worth it. In fact, it could be detrimental to your physical and mental health. In reality, plans and programs that promise rapid weight loss or extreme results are best avoided.
Rapid weight loss diet is a type of diet in which you lose more than 2 pounds (1 kilogram, kg) a week over several weeks. To lose weight this quickly you eat very few calories.
Losing weight too quickly can damage your metabolism
If you lose more than about 8 pounds in a month, not only will you likely not be able to keep it off, but it also means you probably engaged in unhealthy behaviors to get there.
"Women and men of average height need to gain or lose about three and a half and four kilograms, or about eight and nine pounds, respectively, for anyone to see it in their face.
Five pounds per week is an aggressive, unrealistic, and potentially unhealthy weight-loss goal. You did not put all the weight on in one month, so you should not expect to lose it all in one month either! As a general rule, you should aim for 1 to 2 pounds of weight loss per week.
Losing significant amounts of weight quickly is not recommended and may be dangerous. The Center for Disease Control (CDC) recommend people looking to lose weight aim to lose between 1–2 pounds per week for safe, healthy weight loss.
If you're losing weight without trying and you're concerned about it, consult your health care provider. As a rule of thumb, losing more than 5% of your weight over 6 to 12 months may indicate a problem.
According to the American Cancer Society, significant weight loss happens most often with cancers that affect the stomach, pancreas, esophagus and lung.
According to many experts, losing 1–2 pounds (0.45–0.9 kg) per week is a healthy and safe rate (1, 2, 3 ). 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 , 6 , 7 , 8 ).
A healthy weight loss is considered 1 to 2 pounds per week, so losing 5 pounds in two weeks or 2.5 pounds per week is a bit more ambitious. You will have to modify your diet and add regular exercise to make this weight loss happen.
So what is the magic number to lose weight and keep it off? According to the Centers for Disease Control and Prevention (CDC) , it's 1 to 2 pounds per week. That means, on average, that aiming for 4 to 8 pounds of weight loss per month is a healthy goal.
The first place men typically lose weight is the belly, while women tend to lose weight all over, but hold onto weight in their thighs and hips, Dr. Block explains.
How much weight a person needs to lose for it to be noticeable is also subjective as it depends on your frame and starting body mass index, according to Guzman. On average, a 15 to 20-pound loss (approximately 2 to 5 percent of your starting body weight) is enough to notice "significant changes in your body," he said.
But do you really know what's realistic? Over the long term, it's smart to aim for losing 1 to 2 pounds (0.5 to 1 kilogram) a week. Generally to lose 1 to 2 pounds a week, you need to burn 500 to 1,000 calories more than you consume each day, through a lower calorie diet and regular physical activity.
No, it is not safe. A month is not enough time to lose so much weight. 20 pounds in a month is a drastic weight loss that can lead to health issues. The healthy amount of weight loss in a month is between 4-8 pounds a month.
When should I see a doctor about unexplained weight loss? You should consult your physician if you have lost more than 5 percent of body weight or 10 pounds without trying in a period of 6 to 12 months. This is especially important if you have other symptoms, too.
“When you lose weight too quickly, your body slows down its calorie-burning process,” explains Dr. Griebeler. “That is your body's way of trying to ensure you don't starve. You might lose a good amount of weight right away, but your metabolism quickly goes into survival mode.”
While losing 7 pounds or more per week is possible, it is certainly not safe and healthy. If you lose weight rapidly, you will only eradicate water from your body and not your body fat. You can't safely burn 7 pounds in just a week (5). Fast weight loss also flushes out stored glycogen and lowers your insulin levels.
When you're trying to lose weight, it's natural to want it to happen very quickly. But people with gradual and steady weight loss (about 1 to 2 pounds per week) are more likely to keep the weight off.
Involuntary weight loss generally develops over weeks or months. It can be a sign of a significant physical or mental disorder and is associated with an increased risk for mortality. The causative disorder may be obvious (eg, chronic diarrhea due to a malabsorption syndrome.