Lose 10 pounds in just two weeks, guaranteed! Sound familiar? So many diets promise miracle weight loss that sounds too good to be true, and generally it is. We talked to experts about what it really takes to lose even one single pound.
The short answer: It depends on what type of pound we are talking about. It’s easy to lose a pound of water or a digit on the scale. It’s losing a pound of fat—and keeping it off—that’s more challenging.
How many calories are in a pound?
In simplest terms, losing fat—even just a pound—means taking in fewer calories and doing more physical activity. There’s been much ado about how many calories make (or break) a pound. “There is an adage that a 3,500 caloric deficit is needed to lose one pound, and this is a good average, but height and weight matter too,” explains Holly Lofton, MD, director of the Medical Weight Management Program at NYU Langone in New York City. There is likely no single answer as to how many calories you’d have to skip to lose one pound, but we do have a ballpark. “You’d need a deficit of 2,000 to 4,000 calories depending on person’s build,” Dr. Lofton says.
(For some context, a McDonald’s Quarter Pounder with cheese has 530 calories; add fries for another 230 and a sugary soda for 70 more.)
But not all calories are equal by any stretch. “If you cut 3,500 calories and just ate ice cream, you would lose less than if you chose asparagus and chicken,” Dr. Lofton says. “You want to eat a protein and carb mix or a protein and vegetable mix,” she says. Her tip: High-fiber, low-calorie vegetables such as cabbage, broccoli, and spinach will allow you to feel fuller, making any caloric deficit easier to manage.
Protein is also key here because it’s super thermogenic, adds Jason Ewoldt, RDN, LD, a wellness dietitian at the Mayo Clinic Health Living Program in Rochester, Minnesota. This is a science-y way of saying that protein turns up the heat in our body’s furnace, which increases our metabolism and our ability to burn fat (which is why so many diets are all about the protein—here are some top plant-based sources).
By contrast, eating just carbs will increase fat storage by raising insulin levels. Here’s what happens: You mow down a bag of chips, your glucose or blood sugar shoots up, and your pancreas produces a large amount of the hormone insulin to take the excess glucose out of your bloodstream. The glucose converts to a starch called glycogen, which is stored in the liver and in muscles. The catch? Your body can only store a limited amount of glycogen, so the excess glucose is stored as body fat.
Our physical build also factors into our ability to lose even just one pound of fat. “If you think of muscle tissue vs. fat tissue, the muscle needs more calories to be maintained,” Ewoldt says, “so one individual could theoretically ingest more calories and still lose weight [compared with someone] who has more adipose fat tissue.”
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How to lose one pound a week?
“In the short term it takes an energy deficit—burning off more than you take in,” says Scott Kahan, MD, MPH, Director of the National Center for Weight and Wellness in Washington, D.C. This is the equivalent of about 500 calories per day below your maintenance level. You can easily determine your maintenance level (the number of calories you should take in to maintain your current weight) with a free online calculator. If it says you can maintain your weight eating about 2,000 calories per day, shave off 500 to lose about one pound per week in the short term, Dr. Kahan says.
But, Ewoldt cautions, “humans are very bad at keeping track of how much they’re eating. They generally underestimate calorie intake—they forget about that candy bar they ate in between lunch and dinner. They forget about pouring a little more orange juice in their glass in the morning—and that all adds up.”
In addition, people “tend to overestimate calorie expenditure. So we go for a walk and think we burn 500 calories, and you put that person in a research setting and it’s actually only 200,” he continues.
Exercise does make a difference though, Dr. Lofton says. She typically recommends a minimum of 180 minutes a week of huffing and puffing for weight loss, and sometimes suggests kicking it up to 300 minutes per week. Some exercises are superior calorie burners than others. These are the workouts that burn the most calories and the workouts that don’t burn nearly as many as you think.
“For most people, focusing on moderately decreasing caloric intake will be more reasonable to achieve than increasing physical activity, though a combination is ideal,” Dr. Kahan says.
“Most important, especially for those who have had challenges managing weight, is figuring out why it’s been difficult to decrease their calorie intake or increase activity.” These may be the real reasons why you can’t lose weight.