Aiming for a small but rapid weight loss target like 6 pounds (lbs) in two weeks might seem safe and achievable. However, despite the deceptively low number, losing 3 lbs per week can be dangerous for your health, and most people will find it highly challenging to achieve without some form of crash diet.
“A general rule of thumb is that 1 or 2 pounds of weight loss a week ensures that a person is doing something sustainable with a low risk of harm,” says Richard Harris, MD, a board-certified internal medicine physician and the chief strategy officer at Nimbus Healthcare in Houston.
How Large a Calorie Deficit Would You Need?
At a basic level, losing weight involves using more daily calories than you consume, called being in a calorie deficit. Although everyone’s metabolism and rate of weight loss are different, roughly speaking you’ll need a daily deficit of between 500 and 1,000 calories to lose 1 to 2 lbs per week, which would mean that reaching 3 lbs per week requires a daily deficit of about 1,500 calories.
According to the Dietary Guidelines for Americans, the low range of recommended calories is between 1,600 and 1,800 for women and between 2,000 and 2,400 for men, depending on your age. This means that aiming for a loss of 3 pounds per week would leave too few calories for your body to maintain its normal processes. This could lead to significant health implications and weight regain.
What Are the Risks of Losing 6 Lbs in 2 Weeks?
Rapid weight loss can sound appealing on the surface, which might lead you to try fad diets or extreme exercise trends. But crash dieting has a high risk of adverse effects.
According to Jennifer Brown, MD, a medical writer and board-certified physician in obesity medicine and family medicine in Lewisburg, West Virginia, losing weight quickly can disrupt the rate at which your body converts food into energy, or metabolism, making long-term weight management more challenging.
Other potential implications of losing weight too quickly include the following:
“Plus, rapid weight loss can cause people to feel miserable due to fatigue,” says Dr. Brown.
If you’re trying to reach an extreme calorie deficit through excessive exercise, you also risk overtraining and injury.
Is It Safe to Lose Water Weight?
On average, water accounts for around one-half to two-thirds of a person’s body weight, and it’s vital for many functions, including making your cells, tissues, and blood vessels work properly; controlling body temperature; carrying nutrients; and removing waste.
However, various factors can temporarily shift how much water is in the body. Water weight refers to the natural 1 to 5 lbs that naturally fluctuate when the body manages fluid levels.
Because water weight often leaves the body before fat or muscle loss, some people purposely dehydrate themselves to target rapid weight loss. They might attempt dangerous approaches like crash dieting, overuse of saunas, or improper use of diuretics.
This might seem like an easy way to work toward losing 6 lbs in 2 weeks, but the whole picture isn’t so simple. Dr. Harris warns against this idea, as methods that intentionally involve dehydration can lead to a dangerous imbalance of electrolytes.
As well as dehydration being a problem on its own, Brown adds that water weight will come right back once you replenish your fluid levels. “Water reserves fluctuate daily among individuals, which is why I usually recommend patients weigh in once a week at the same time. Weighing daily can be frustrating because varying water reserves can cause weight to fluctuate by 2 or 3 pounds or more,” she says.
According to Harris, several factors can contribute to this fluctuation:
Diet, specifically an increase in carbohydrates, sodium, or alcohol intake
Hydration level
Intensity of exercise, which can mean sweating more
Medication, including blood pressure medication and some steroids
Fullness of the bladder or bowels
Other medical conditions, including some kidney, heart, and liver problems
Instead of aiming to lose water weight through unsafe means, consider options that more gently and sustainably reduce that fluctuation. These might include the following:
Incorporating nutritional balance within your daily diet
Maintaining regular physical activity
How to Lose Weight Steadily and Sustainably
You might feel pressure to lose weight quickly, but slow weight loss leads to a more sustainable long-term outcome. Brown suggests that you can safely maintain a monthly weight loss of 4 to 6 lbs by setting small goals.
Setting yourself more achievable goals not only reduces frustration along the way but also has a healthier impact on your body.
“Losing weight quickly rarely results in long-term weight loss. The dietary restrictions and exercise habits that result in significant weight loss over a short period aren’t sustainable, and the weight usually quickly returns,” Brown says.
Harris prefers that patients think of weight loss as a lifestyle change, rather than basing it all on the number on the scale. “Sustained and maintained weight loss comes down to finding a way to restrict calories in a way that does not feel too restrictive,” he says.
When it comes to nutritional changes, Harris suggests prioritizing ample hydration, protein, and fiber to provide your body with the necessary nutrients and support you in feeling full after meals.
Harris also suggests a multipronged approach for movement throughout the day, which could include several tactics:
“Working with a weight management professional can be beneficial in helping individuals find and stick to a comprehensive plan,” he says.
Alongside regular exercise, good sleep hygiene and minimizing stress are essential pieces of sustainable weight loss.
The Takeaway
Losing 6 lbs in two weeks might not be a safe target. Wanting to look and feel your best is fine, but the safest and most effective approach to weight loss involves steady and sustainable changes.
Consider all of your lifestyle factors when aiming to start a weight loss journey, including sleep, stress, diet, and movement.
Quick weight loss goals often require fad diets, which usually lead to weight regain and can cause adverse effects.
Reaching and maintaining your health goals is attainable, either by making small changes in your daily routine or by seeking support from a personal trainer, registered dietitian nutritionist, or healthcare professional.
Tara Collingwood, RDN, is a board-certified specialist in sports dietetics, an American College of Sports Medicine–certified personal trainer, and a media spokesperson. As a sports dietitian, she has worked with the U.S. Tennis Association, the Orlando Magic, World Wrestling Entertainment, runDisney, the University of Central Florida, and numerous professional and amateur athletes. Collingwood is the author of Pregnancy Cooking and Nutrition for Dummies and a coauthor of the Flat Belly Cookbook for Dummies.
She appears regularly on national and local TV, and speaks around the world to business teams on how to manage energy physically, emotionally, mentally, and spiritually. She previously served as a national spokesperson for the Academy of Nutrition and Dietetics.
Collingwood double-majored in dietetics as well as nutrition, fitness, and health at Purdue University and earned a master's degree in health promotion from Purdue University.
Zuri White-Gibson (she/her) is a lover of words, community, and accessible healthcare resources.
In addition to Everyday Health, you can find some of her work — often focusing on the intersections of health, mental wellness, gender and sexuality, and Black communities — at some of your favorite health and news sites, including Healthline, Psych Central, Prism, and Stacker.
Everyday Health follows strict sourcing guidelines to ensure the accuracy of its content, outlined in our editorial policy. We use only trustworthy sources, including peer-reviewed studies, board-certified medical experts, patients with lived experience, and information from top institutions.
Resources
Calorie Deficit: What To Know. Cleveland Clinic. December 21, 2022.
