How Long Does It Take to Lose 10 to 15 Pounds?

A 10- to-15-pound weight loss can have a significant impact on your health. Depending on your situation, a modest drop on the scale (just 5 to 10 percent of your total body weight) can help improve major markers of health, including blood pressure, blood sugar and cholesterol levels, according to the Centers for Disease Control and Prevention (CDC).

But how long does it take to lose this amount of weight in a healthy way?

Here, Sylvia Gonsahn-Bollie, MD, a dual board-certified internal medicine physician and obesity medicine specialist and author of ‌​Embrace You: Your Guide to Transforming Weight Loss Misconceptions into Lifelong Wellness,‌ shares strategies to safely shed 10 to 15 pounds (and sustain it).

When it comes to sustainable weight loss, slow and steady is key. Healthy weight loss is equivalent to 1 to 2 pounds per week (or 4 to 8 pounds per month), Dr. Gonsahn-Bollie says.

"Slowly losing weight gives your body time to adjust hormonally and sends the sign that weight loss is safe and not a threat," she says. What's more, people who lose weight at this pace (1 to 2 pounds per week) tend to maintain it in the long term, according to the CDC.

If your objective is weight loss, you might be eager to slash the number on the scale quickly (read: those scant 1 to 2 pounds a week may seem like a snail's pace).

But shedding pounds too swiftly can sabotage your long-term goals. That's because "your body's default mode is fat storage," Dr. Gonsahn-Bollie says. In other words, it's hardwired to ensure that you have enough fat stores to survive. So, if you rapidly lose weight, your body will interpret the sudden loss as harmful, she explains.

Take the example of ‌The Biggest Loser‌ study in the May 2016 issue of ‌Obesity‌. Researchers studied 14 people who participated in ‌The Biggest Loser‌, a reality TV weight-loss competition, to assess long-term changes in their resting metabolic rate (i.e., the caloric energy a person expends each day at rest) and body composition.

"We learned that when we lose weight too quickly, the body fights to regain the weight it lost," Dr. Gonsahn-Bollie says. (Keep in mind, this occurs regardless of how fast weight is lost.) "Specifically, the body sends hormones to slow metabolism and increase appetite." Adding insult to injury, "since the body's default is fat storage, it's harder to lose weight after regaining it," she says.

In addition to regaining weight, Dr. Gonsahn-Bollie also points out that losing pounds too speedily also comes with other health risks such as:

• Muscle loss
• Bone damage
• Disruption to other normal body functions such as menstruation, fertility and more

"Many people mistakenly think weight loss is just 'calories in vs. calories out,' but there are over 100 factors [both controllable and uncontrollable] that impact weight loss," Dr. Gonsahn-Bollie says.

Some uncontrollable factors include, per Dr. Gonsahn-Bollie:

• Genetics
• Place of birth
• Race/ethnicity
• Racial bias
• Weight bias
• Age

While there are many factors beyond our control when it comes to weight gain or weight loss, concentrating on those we can control is a smart strategy. To safely lose up to 15 pounds and sustain it in the long run, focus on the following:

While weight loss is more complicated than "calories out vs. calories in," calculating your correct calorie deficit (the amount of calories you must decrease per day to lose a pound or two a week) can help with understanding your physical energy needs, Dr. Gonsahn-Bollie says.

"Start by measuring or calculating your maintenance calories using the Total Daily Energy Expenditure equation (TDEE) … [which] estimates how many calories you [burn per day and] need to maintain your current weight based on your activity level," she explains.

While there are several different formulas for determining your TDEE, you can start with this simple TDEE calculator (based on the Mifflin-St Jeor equation) that takes into account factors including gender, age, weight, height, level of activity and body fat percentage.

Once you know your TDEE, you can figure out the daily calorie deficit you'll need to lose weight. "One pound of weight loss is 3,500 kcals, so if you want to lose 1 to 2 pounds a week, you need to subtract 500 to 1,000 kCals from your daily calorie (either intake by eating less calorie-dense foods or burning more calories)," Dr. Gonsahn-Bollie says.

"However, this rule isn't 'one size fits all,'" she adds. Again, many factors affect weight loss and your specific caloric needs, including your age, gender, height, present weight, body frame, level of physical activity and hormones, according to Columbia University.

"Not all calories affect your body equally," Dr. Gonsahn-Bollie says. Think: Eating half a candy bar might be equivalent in calories to a banana, but the former is full of added sugar and fats whereas the latter is loaded with fiber and other nutrients.

Which is why it's no surprise that ultra-processed foods (like potato chips, sweetened beverages and processed meats) are associated with more weight gain, Dr. Gonsahn-Bollie says. Not only do they "tend to be higher in calories … [but] there are also some scientific studies that suggest these foods cause inflammation and impact the hormones that regulate fat storage," she explains.

In fact, certain additives (such as artificial sweeteners, colors and emulsifiers) and other compounds (like bisphenol A and pesticides) found in food have been shown to disrupt endocrine function, insulin signaling, and/or adipocyte (fat cell) function, according to a February 2014 article in ‌Current Obesity Reports‌‌.‌ And all these things play a part in weight loss (or weight gain).

Put simply, "food quality impacts the hormonal weight-loss signals your body receives," Dr. Gonsahn-Bollie says.

For sustainable weight loss, work on building a well-rounded eating plan that includes all macronutrients (complex carbohydrates, healthy fats and leans proteins), a focus on hydration and a limited amount of sugar and/or refined, processed carbohydrates, she says.

"The American Heart Association recommends 150 to 300 minutes of moderate physical activity a week to maintain weight," Dr. Gonsahn-Bollie says. So if your goal is to lose weight, you will either need to engage in more vigorous exercise or spend more time exercising in general, say 300 to 450 minutes per week, she says.

OK, that sounds like A LOT. But don't fret: Not every minute needs to be strenuous or even spent at a gym. For instance, a leisurely stroll after supper is a stellar way to sneak in more steps and burn calories. Similarly, brisk walk breaks between meetings or during your lunch break add up quickly too.

Case in point: People in the National Weight Control Registry (NWCR) — the most extensive study of individuals who've maintained 30+ pounds of weight loss for over one year — do an average of 420 minutes of weekly exercise (or an hour per day), which consists mainly of walking, Dr. Gonsahn-Bollie says.

Still, everyone is different. If walking doesn't float your boat, try another activity that you enjoy. Finding a type of exercise that excites you will make it more likely you'll stick to it for the long haul.

The ability to shed pounds is closely connected to sleep quality. That's because "all your weight and appetite-regulating hormones reset while you sleep," Dr. Gonsahn-Bollie says.

So if your slumber is scarce, the hormones that affect your weight may get thrown out of whack. Indeed, a November 2015 study in ‌Sleep Science‌ concluded that sleep deprivation can contribute to changes in the neuroendocrine system that result in metabolic dysfunction.

"Therefore, sleeping seven to nine hours a night is essential because, depending on the individual, it takes this long for your weight and appetite-regulating cycle to reset," Dr. Gonsahn-Bollie says.

Your stress level may be limiting your weight loss efforts. Matter of fact, research has found that cortisol — a stress hormone — can contribute to belly fat.

"Hormonally chronic stress [stress lasting more than 72 hours] can cause you to stop losing weight and even cause you to gain weight," Dr. Gonsahn-Bollie says.

A simple way to understand why this may happen is that when you're experiencing extreme or excessive stress, your body construes it as a threat and switches into a protective mode.

To get your weight loss back on track, prioritize stress management. Not sure where to start? Deep breathing, meditation and exercise are all solid stress relievers.