There's no quick fix when it comes to weight loss. But understanding how much weight you can lose in six weeks can help you safely and sustainably work toward your ultimate goal.
So what does healthy weight loss look like? On average, it's recommended to lose between 1 to 2 pounds per week, per the Centers for Disease Control and Prevention (CDC).
If you're working toward a slimmer frame, you can expect to lose about 12 pounds maximum in six weeks. For most people, dropping any more weight in this amount of time is not possible or recommended.
To lose between 20 and 30 pounds in six weeks, for example, you'd need to lose between 3 and 5 pounds per week, which far exceeds the healthy weight-loss rate suggested by the CDC and other expert sources.
How Weight Loss Works
Weight loss requires burning more calories than you take in. The size of the calorie deficit will dictate how much and how fast you lose, but doctors and health organizations advise that weight loss be gradual and steady.
The reason the CDC-recommended pace of 1 to 2 pounds per week is considered healthy? It's usually achieved with manageable decreases in portion sizes, improvements in the quality of food choices and more physical activity.
For weight maintenance, the 2020-2025 Dietary Guidelines for Americans recommends a daily intake of 1,600 to 2,400 calories for people assigned female at birth (AFAB) and 2,200 to 3,000 calories for people assigned male at birth (AMAB), depending on their activity level.
To achieve steady weight loss, it's suggested to cut approximately 500 to 1,000 calories from your daily diet, per the Mayo Clinic. That's because you lose 1 pound when you burn about 3,500 more calories than you consume.
This calculation has its flaws, though, because it doesn't always accurately account for energy expenditure, according to June 2013 research in the International Journal of Obesity. You might also have a weight-loss plateau as your metabolism slows in response to consuming fewer calories, according to the Mayo Clinic. In this case, you may need to create a deficit greater than 3,500 calories to keep losing weight.
However, your calorie intake should not fall below 1,200 per day if you're a person AFAB or 1,500 per day if you're a person AMAB, except under the supervision of a health professional, according to Harvard Health Publishing.
Why? Eating too few calories can endanger your health by depriving you of necessary nutrients, and it can also make weight loss more difficult. Fortunately, most people can create a sufficient deficit through diet and exercise without dipping below that threshold.
How to Lose Weight in 6 Weeks
1. Set a Realistic Goal
Rather than figuring out how to lose 20 to 30 pounds in six weeks, stick with the expert-recommended pace of 1 to 2 pounds of weight loss per week, or between 6 and 12 pounds in six weeks.
You may lose slightly more than that at first, because your body can quickly shed water weight when you make dramatic changes to your diet and exercise, according to the Mayo Clinic. Over a few weeks, though, your weight loss should level out to a healthy pace.
2. Choose a Healthy Eating Plan
There are several eating plans that have been shown to promote weight loss. The Mediterranean diet, which consistently ranks on the top of U.S. News & World Report's annual list of the best diets, is touted for its manageable approach that emphasizes whole foods without over-restricting.
If diets aren't for you, make healthy food swaps instead. Trade soda for lemon water, iced tea for unsweetened tea, white rice for cauliflower rice or potato chips for baked kale chips to incorporate more whole foods while still enjoying your go-to meals and snacks. The key is to get creative in the kitchen and recreate your favorite recipes using healthy alternatives.
If you have special dietary considerations or need more support in choosing an eating plan, consider working with a registered dietitian.
3. Steer Clear of Fad Diets
Fad diets like the cabbage soup diet, the Atkins diet and even the keto diet promise rapid weight loss and often sound too good to be true.
They typically eliminate entire food groups, have strict menus and say nothing about exercise or lifestyle changes, per the American Academy of Family Physicians. Some recommend specific products, supplements or detox kits, which may put you at risk for potentially harmful side effects.
These programs often lack scientific evidence, can be unsafe and can affect your health in the long run, according to the National Center for Complementary and Integrative Health. For instance, crash diets can slow down your metabolism and make it harder to maintain a healthy weight.
4. Move More
Exercise and diet go hand in hand. To support your six-week weight loss goals, the CDC recommends including both aerobic exercise (cardio) and strength training in your routine.
A November 2020 study in Medicine & Science in Sports & Exercise found that 300 minutes of moderate-intensity exercise (think: brisk walking or light bicycling) per week helped expedite weight loss, partly because the activity reduced participants' levels of leptin, a hormone associated with appetite.
If you're new to exercising or haven't worked out for a long time, talk to your doctor before you begin your six-week health and fitness plan. Typically, you will start out with smaller amounts of activity and increase your efforts gradually.
Can You Lose 20 or 30 Pounds in 6 Weeks?
Can you lose 30 pounds in six weeks? Maybe. But should you? Typically, no, as weight loss that rapid far exceeds the healthy pace recommended by the CDC.
Losing between 20 and 30 pounds in six weeks, for example, comes to a daily deficit of 1,700 to 2,100 calories — more than many adults can burn. People who have extreme overweight or elite athletes might be able to create this deficit, but it's otherwise unhealthy for most people.
However, losing that much weight in a short period may be necessary for some people who have obesity to avoid medical complications.
In these cases, a very-low-calorie diet, known as a VLCD, of 800 to 1,000 calories may be prescribed by their doctor and administered under medical supervision, per the National Health Service (NHS). Under such an extreme plan, meals are usually replaced with supplements like shakes.
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Why Fast Weight Loss Isn't Healthy
It's typical to be eager to hit your goals as you embark on your six-week weight loss challenge. But while rapid weight loss might be possible, losing weight too fast can come with some major consequences or backfire entirely.
1. Deprives You of Nutrients
Losing weight at a faster rate than 2 pounds per week often means not consuming enough energy and nutrients to keep your body functioning properly, per the Academy of Nutrition and Dietetics. This can lead to fatigue, weakness and brain fog, according to the NHS.
2. Breaks Down Muscle
Your body will start to burn lean body mass as it attempts to cope with the lack of calories coming in. It may begin to break down muscle (not fat) for energy because you're not getting enough fuel from food, according to a January 2016 study in Obesity.
Losing muscle is not a good thing, especially if you're trying to lose weight, because muscle burns more calories than fat, according to the Mayo Clinic. That means the more muscle you have, the more calories you burn.
3. Slows Your Metabolism
Losing a notable amount of muscle can in turn make your metabolism run more slowly in an effort to conserve energy, per the Mayo Clinic. Fatigue, feeling cold and constipation can all occur as a result, according to the Cleveland Clinic.
4. May Lead to Weight Regain
Quickly losing weight often leads to weight regain, according to a January 2018 analysis in Medical Clinics of North America.
For instance, in that same Obesity study, researchers assigned about half the participants to a diet of 500 calories per day for five weeks, and the other half to a diet of 1,250 calories per day for 12 weeks. The groups lost similar amounts of weight, but those who followed the extremely low-calorie diet lost more muscle and experienced more post-diet weight regain.
5. Can Cause Gallstones
Losing weight too quickly can also lead to gallstones: A daily diet of 800 calories or fewer can increase the risk of gallstones, according to Johns Hopkins Medicine. As the body metabolizes fat during fast weight loss, it can cause the liver to secrete cholesterol into bile and form stones.
Gallstones can cause severe abdominal discomfort and you may need to undergo surgery to have them removed.
- Centers for Disease Control and Prevention: Losing Weight
- Harvard Health Publishing: "Calorie counting made easy"
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- Academy of Nutrition and Dietetics: "4 Ways Low-Calorie Diets Can Sabotage Your Health"
- Johns Hopkins Medicine: "Gallstones"
- Obesity: "The effect of rate of weight loss on long‐term weight regain in adults with overweight and obesity"
- Medicine & Science in Sports & Exercise: "Exercise for Weight Loss: Further Evaluating Energy Compensation with Exercise"
- Centers for Disease Control and Prevention: "Active Adults"
- Mayo Clinic: "Counting calories: Get back to weight-loss basics"
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- Mayo Clinic: "Getting past a weight-loss plateau"
- American Academy of Family Physicians: "Nutrition for Weight Loss: What You Need to Know About Fad Diets"
- National Center for Complementary and Integrative Health: “'Detoxes' and 'Cleanses': What You Need To Know"
- Medical Clinics of North America: "Maintenance of lost weight and long-term management of obesity"
- Cleveland Clinic: "Hypothyroidism"
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- U.S. News & World Report: "Best Diets 2021"
- Mayo Clinic: "Metabolism and weight loss: How you burn calories"