8 Big, Fat, Weight Loss Myths

It’s no secret that losing weight—and keeping it off—is tough. That’s all the more reason to avoid moving up a pant size in the first place. Here we correct 8 common weight loss myths to help you play defense in the battle of the bulge.

MYTH #1: “I can lose weight later.”

Let’s say you’ve been on vacation. Or it’s the holidays. You know you’ve put on a few pounds, but so what? You’ll just cut back when things get back to normal, and your waist will shrink back to its pre-vacation or pre-holiday size in a few weeks, right?

Not so fast.

“A student of mine was interested in how long it would take for somebody to lose the weight they had gained from holiday overeating if all they did was go back to their regular pre-Thanksgiving diet,” says Kevin Hall, senior investigator in the Laboratory of Biological Modeling at the National Institute of Diabetes and Digestive and Kidney Diseases.

“The funny thing was that they wouldn’t have lost all the new weight by the time the next holiday period came around.”

So just several weeks’ worth of indulgence can have lasting consequences.


“If you never quite lose the weight that you gained the previous year, you’re just ratcheting your weight up year after year after year,” explains Hall.

Why does it take so long to lose those extra pounds that you put on so quickly? The old rule of thumb—that you can expect to lose a pound for every 3,500 calories you cut—is wrong for several reasons.1,2

For example:

  • You’ve lost muscle.

The 3,500- calorie rule assumes that you’ve lost only fat. In fact, about 25 percent of the weight that dieters lose is lean tissue.

“Most of the lean body mass is skeletal muscle,” says Hall. “And even at rest, it burns more calories than fat tissue.”

  • Your organs are smaller.

“As you lose weight, your liver, kidneys, and other organs shrink,” says Hall. “So the number of calories that are required to keep those organs operating goes down.”

Roughly 60 to 70 percent of your calories are used just to keep your heart beating, your kidneys filtering blood, etc., 24 hours a day.

“The liver and kidneys are much smaller than the sum total of your skeletal muscles,” explains Hall. “But per unit weight, they are 10 to 20 times more active than skeletal muscle at rest. So even small changes in these organs can make relatively substantial changes in metabolic rate.”

Metabolic slowdown. Lost at least 10 percent of your weight? To keep it off, you may have to eat 10 to 15 percent fewer calories than you did before you gained it.
Metabolic slowdown. Lost at least 10 percent of your weight? To keep it off, you may have to eat 10 to 15 percent fewer calories than you did before you gained it.
  • Exercise burns fewer calories.

As your body becomes smaller, moving it around becomes easier. Going for a walk or climbing the stairs burns fewer calories than it used to.

  • Your metabolism is slower.

“Your metabolism slows down when you cut calories,” says Hall. It’s as though your body is hunkering down to face scarcity, so it burns fewer calories per minute.

“We’ve actually measured contestants on the television show ‘The Biggest Loser,’” says Hall. “These folks were doing a lot of exercise, so they were preserving their lean tissue as much as possible.” (Only 18 percent of their lost weight was lean tissue.) But their metabolic rate still fell by an average of about 800 calories per day.3

“You could explain only about 300 of the 800 calories by their smaller size,” notes Hall. The remaining 500 calories were due to slower metabolism.

“Now, their case is an extreme,” he adds. But even if you went from, say, 165 pounds to 145 pounds, you would have to eat fewer calories than you ate before you first gained those 20 pounds.

“Once you lose at least 10 percent of your weight and your weight is stable, you may need to eat 10 to 15 percent fewer calories to keep the weight off,” says Hall. That’s because your body burns fewer calories both at rest and when you move.4

Hall and his colleagues have created an online body weight calculator that considers all those changes to estimate how long it will take you to lose, say, 20 pounds.

“We built our online simulators for people to better understand how changes in diet and physical activity can be traded off to both get to a goal and then maintain that goal permanently,” he explains.

(Go to bwsimulator.niddk.nih.gov or download the free Body Weight Simulator app for the iPhone.)

Bottom line: A slower metabolism and less lean mass make it hard to lose all the extra pounds you gain.

MYTH #2: Once I lose weight, it’ll stay off.

You go on a diet for six months. Gone are those extra 10 or 20 pounds. But slowly, they start to reappear. That’s what happens in most large studies. 5 What’s up?

“We’ve looked at body weight changes to figure out what people have done to their food intake, and what we found was pretty surprising,” says Hall.

“Initially, most people go like gangbusters. They’re pretty good about sticking to their weight-loss program for a while.”

But they gradually start to eat more, and they don’t notice because they keep losing weight. That’s because they’re still eating less than when they started dieting.

Daily Calorie Intake VS. Body Weight Chart

daily calorie intake vs body weight chart
Most people slash calories (blue line) when they start a diet. Then they gradually start eating more, but don’t realize it because they’re still losing weight (red line)…at least for a while. Source: Obesity 22: 2105, 2014.

“By the time they reach their maximum success, after six to eight months, they’re about 80 percent of the way back to what they were eating at the beginning of the weight-loss program,” says Hall.

“They’re eating, say, 100 calories less per day, whereas they started out probably cutting about 700 calories out of their diet. So 80 percent of that initial diet has been lost.”

And their weight creeps back up.

“We’re working on tools to track peoples’ weight,” says Hall, “so we can provide early warning signs that they’ve started to back off on their original diet.”

Bottom line: Many dieters regain lost weight because they gradually start eating more.

MYTH #3: Fat is fat, no matter where it is.

When you overeat, your body needs to stash the excess calories somewhere. But your odds of losing those extra pounds—and their impact on your health—depend on where the fat ends up. And much of that is beyond your control (see No. 5).

“We know that if people gain leg fat, they actually gain new fat cells, so they’re sort of stuck with new fat cells,” says Michael Jensen, director of the Obesity Treatment Research Program at the Mayo Clinic in Minnesota.

That’s not true for belly fat.

“At least with modest weight gain, almost all the weight gain in upper body fat is an increase in fat cell size,” says Jensen. “Each fat cell just agrees to store a little bit more. That makes upper body fat easier to lose.”

Jensen and his colleagues fed 23 lean men and women an extra 400 to 1,200 calories a day as ice cream shakes, Snickers bars, and Boost Plus energy drinks.6 After two months, their weight jumped by about eight pounds.

After another two months—during which the participants cut their calories and boosted their exercise—they only lost an average of six pounds. And what remained was mostly extra leg fat.

“When we look at the loss of that gained weight, upper body fat goes away first and leg fat goes away last, because you created a whole new set of cells there,” says Jensen. “Once you have a new fat cell, it’s very hard to get rid of it, so it’s the last place you will lose weight.”

And it’s not just a few cells. In another study, Jensen found that 3½ pounds of new leg fat created roughly 2.6 billion new fat cells within two months.7 Sure you need that cupcake?

Of course, those upper body fat cells can’t keep getting bigger and bigger.

“Your fat cells can only get so big,” explains Jensen. “From the smallest fat cell to the biggest fat cell is only about a four-fold increase. And we all know people who have gained more than four times as much fat as they had when they were skinny. So eventually, you have to start recruiting new fat cells.”

Apparently, we all have pre-adipocytes (pre-fat cells) that are just waiting to be pressed into service whenever we need them.

The irony: storing more fat in your legs is actually healthier.

“People who gain predominantly leg fat tend to have a much better metabolic profile than people who put on a lot of abdominal fat,” notes Jensen. “They’re less likely to get diabetes, less likely to get high cholesterol and high triglycerides, and less likely to get hypertension and sleep apnea.

“My biggest worry is when a patient comes in with a big gut and skinny legs,” he adds. “I know they’re probably in trouble.”

It’s not clear why upper body fat—especially the deep-belly visceral fat—is worse. One possibility: visceral fat cells may send more fat to the liver. Or a generous layer of visceral fat may be a sign that your subcutaneous fat is faulty.8

“One speculation is that people gain visceral fat because the subcutaneous fat in their abdomen and thighs is not doing its job,” says Jensen. “Its job is to sequester fat from the excess calories you ate so that it can’t harm your lean tissue.

location of muscle liver visceral fat on body
Muscle, liver, and visceral fat are more harmful than subcutaneous fat.

“And if the subcutaneous fat can’t do its job, the fallback job goes to the visceral fat. And if the visceral fat can’t do its job, the fat starts building up in your liver and muscles and other places where you really, really don’t want it.”


“Those organs can’t package fat in the safe triglyceride form very well,” explains Jensen. “So the fatty acids—the individual components of triglycerides—can interfere with cell function.”

You might end up with non-alcoholic fatty liver disease, for example.

“It’s as though you kept putting gas in the gas tank when it’s full and now it’s running all over the side of your car,” says Jensen. “It’s a bad situation.”

Bottom line: Extra calories can lead to leg fat that’s tough to lose or deep-belly fat that’s a risk to your health.

MYTH #4: You have to go out of your way to overeat.

You needn’t sit at home all day and stuff your mouth with potato chips, candy bars, and ice cream to end up with a spare tire. You just have to eat—like most of us do— in restaurants, shopping malls, movie theaters, ballparks, airports, drug stores, gas stations, and at virtually every other public place.

“Food is now available everywhere,” says Kevin Hall, of the National Institute of Diabetes and Digestive and Kidney Diseases. “It’s even socially acceptable to eat during meetings. In fact, food is now provided at meetings.”

Where isn’t food available? And the size of meals has grown.

“The restaurant is a toxic environment,” says Susan Roberts, director of the Energy Metabolism Laboratory at the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University. “The portion sizes are enormous, and the calories are excessive.”

In a 2013 study, she and colleagues analyzed the calories in the 42 most frequently eaten meals from independent and small chain sit-down restaurants in the Boston area. They included popular cuisines like Mexican, American, Chinese, Italian, Japanese, Thai, Indian, Greek, and Vietnamese.

“These establishments make up half of all restaurants but offer no calories or other Nutrition Facts on their menus,” notes Roberts.

The average meal had roughly 1,300 calories—about two-thirds of the calories an average person needs in a day.9

“And people have no idea how many calories they’re eating,” adds Roberts.

Bottom line: What’s typically served in restaurants can make you gain weight.

MYTH #5: All extra calories are equal.

Can you change where your extra calories end up?

“There’s certainly some genetic component to it,” says Mayo’s Michael Jensen.

“Women, because of female hormones, are going to be more able to store leg fat than men.” (That is, until menopause, when they may wonder where that waist went.)

“It turns out that smokers are probably not as good at making new leg fat cells,” he adds. “And people who drink a lot of alcohol tend to store more fat in the abdominal area.”

Saturated fat may also make a beeline to your belly. Swedish scientists added enough 250-calorie muffins—typically three a day—to the diets of 39 young lean adults to make them gain about 3½ pounds over seven weeks. But those who got muffins made with saturated fat (palm oil) gained more visceral and liver fat than those who got muffins made with a polyunsaturated fat (sunflower oil).10

And it’s not just palm oil. The same researchers found more liver fat when they fed obese people butter instead of sunflower oil. (That study didn’t measure visceral fat.)11

The extra calories from added sugars like sucrose and high-fructose corn syrup may also prefer to settle in deep-belly fat.

When researchers gave 32 overweight or obese middle-aged men and women a high dose of fructose or glucose for 10 weeks, both groups gained about three pounds.12

“But fructose significantly increased visceral fat, while glucose did not,” explains Kimber Stanhope, associate researcher at the University of California, Davis.

(Since we get glucose from nearly all carbs but fructose only from sugars, the only way to limit fructose is to limit added sugars—from soft drinks, frappuccinos, cookies, cakes, ice cream, muffins, doughnuts, scones, candy, and other sweets.)

“A Danish study that gave overweight people a much smaller dose of fructose—a liter of sucrose-sweetened cola per day for six months— also found an increase in visceral fat,” notes Stanhope. 13 “More studies are needed, but this direct experimental evidence suggests that sugars may increase visceral fat.”

Bottom line:: Excess calories from foods high in sugars or saturated fats may be more likely to settle in deep-belly fat.

MYTH #6: You can boost your metabolism.

“Metabolism boost,” boasts the label of Organic Matcha green tea powder, which also claims to be a “calorie burner.” “Supports energy and metabolism,” claims Herbalife Herbal Tea Concentrate.


Most typical restaurant dishes have at least 1,000 calories. It’s easy to gain weight if you eat what restaurants serve.

Food Calories
Uno Chicago Classic Deep Dish Pizza 2,300
Famous Dave’s Baby Back Ribs (full rack) w/baked beans, fries, corn bread 2,110
Outback Steakhouse 16 oz. Herb Prime Rib w/Caesar salad, garlic mashed potatoes 2,000
Buffalo Wild Wings Traditional Wings w/blue cheese (small order, around 10 wings) 1,940
Five Guys Bacon Cheeseburger w/regular fries 1,870
IHOP Hearty Ham & Cheese Omelette w/3 buttermilk pancakes w/syrup 1,730
Chili’s Smoked Chicken Quesadillas 1,720
Joe’s Crab Shack Seaside Platter (fish, chips, jumbo shrimp, breaded scallops, coleslaw) 1,650
Olive Garden Chicken Alfredo 1,540
On The Border Mesquite-Grilled Steak Fajita w/3 flour tortillas, sour cream, guacamole, cheese, pico de gallo, rice, black beans 1,460
Outback Steakhouse 14 oz. New York Strip Steak w/Caesar salad, dressed baked potato 1,410
P.F. Chang’s Kung Pao Chicken w/rice 1,370
Chili’s Cajun Pasta with Grilled Chicken 1,270
Denny’s All-American Slam (3 eggs, cheese, 2 bacon strips, 2 sausage links, hash browns, 2 slices toast) 1,220
P.F. Chang’s Combo Fried Rice 1,210
Chili’s Skillet Chocolate Chip Cookie 1,200
Chili’s Molten Chocolate Cake 1,160
Maggiano’s Shrimp Scampi 1,130
Olive Garden Spaghetti with Meatballs 1,120
Romano’s Macaroni Grill Lasagna Bolognese 1,110
Olive Garden Fettuccine Alfredo 1,090
Häagen-Dazs Banana Split Dazzler Sundae 1,080
California Pizza Kitchen Original BBQ Chicken or California Veggie Pizza 1,070
P.F. Chang’s Shrimp Pad Thai 1,070
Olive Garden Eggplant Parmigiana w/spaghetti 1,050
California Pizza Kitchen California Cobb Salad w/bleu cheese dressing 1,030
Pei Wei Chicken Lo Mein (Original size) 1,030
Chipotle Chicken Burrito (rice, black beans, salsa, sour cream, cheese) 1,020
Uno Pepperoni Flatbread Pizza 990
Häagen-Dazs Classic Hot Fudge Sundae (reg. size) 980
Panera Mac & Cheese (full size) 980
IHOP Original Buttermilk Pancakes (5) w/syrup 970
IHOP Original French Toast w/syrup 940
Romano’s Macaroni Grill Mushroom Ravioli 930
Cinnabon Classic Roll 880
Panera Fontina Grilled Cheese Sandwich 850
The Cheesecake Factory Original Cheesecake 820
Starbucks Java Chip Frappuccino (venti, 24 fl. oz.) 600
Source: restaurant chains. Chart compiled by Paige Einstein.

The catch: companies need virtually no evidence to make those claims. “This boosting of metabolism is pretty overblown,” says Tufts’ Susan Roberts.

“Magazines and supplements love to talk about ways to boost your metabolism. But you can eat a brownie with 700 calories in about 10 seconds, and there is nothing that you can remotely do to change your metabolism by anywhere near that much, except to give up your job and spend all your day in the gym.”

Take green tea. Some small studies report that it leads to a bump in metabolic rate, but long-term studies find that it makes little or no difference in weight.14

The largest study: With funding from Coca-Cola, researchers randomly assigned 572 people to a weight-loss program with or without three daily cans of diet cola, each fortified with green tea extract (83 mg of EGCG) and caffeine (100 mg). After three months, the diet-cola drinkers had lost no more weight than the others.15

Does anything help you burn more calories per minute?

“Exercise is going to help a bit because muscle is more metabolically active than fat,” says Roberts. “So if you have five more pounds of muscle and five pounds less fat, it will make a bit of difference, but not a huge difference.

“Weight control is dominated by how many calories you eat. That’s the honest truth.”

Bottom line:: Don’t expect to lose much weight from “metabolism boosters.”

MYTH #7: There’s a magic bullet diet.

The Paleo Diet. The Sugar Impact Diet. The New Atkins Diet. All promise to make the pounds peel away fast.

Most experts wouldn’t agree. In 2013, the Obesity Society, American Heart Association, and American College of Cardiology issued a report on overweight and obesity.5 Its advice: cut calories or try a diet that’s low in fat or carbs or whatever.

“We started off with different, almost religious, beliefs as to what diet would be better,” says the Mayo Clinic’s Michael Jensen. “And we wound up being agnostic.

“We looked for studies that had results for at least a year, and preferably two years, because for most of us who treat patients with obesity, it’s not what they did in six months that matters, it’s what they did in two years that really drives our decision making.”

And those longer trials didn’t reveal any magic bullets. “We found that in the end, on average, the diets produced about the same amount of weight loss,” says Jensen.

The key for weight loss is the long game.

“For any given person, it’s really more a matter of what can they stick with,” notes Jensen, “rather than whether there’s a specific diet that we know is best for them ”.

Bottom line:: Don’t pin your hopes on the latest “miracle” diet.

MYTH #8: I can work off the extra calories.

So what if you had General Tso’s chicken or steak fajitas for dinner? So what if you shared a large bucket of popcorn at the movies? You can always work it off, right?

“People totally overestimate how many calories they’ll burn when they exercise,” says Roberts.

“We recently asked people, ‘What do you need to do to lose weight?’ About three-quarters of them said, ‘My trouble is that I stopped going to the gym’ or ‘I’ve been lazy. I need to go to the gym.’ They were beating themselves up because they weren’t doing enough exercise.”

In fact, most studies find that people who are told to cut calories lose more weight than those who are told to exercise more, though a mix of diet plus exercise is best in many studies.16,17

exercise and weight loss
Exercise can help keep you
healthy, but it won’t make the
pounds peel off.

“Exercise for weight loss is often unhelpful,” says Roberts. “Several years ago, a study looked at the individual response to an exercise program. It was terrifying because they found a huge variability.”

UK researchers had 35 overweight or obese men and women exercise (on a stationary bike, treadmill, or stepping or rowing machine) long and hard enough to burn 500 calories per session, five times a week.18

After 12 weeks, the average weight loss was 8 pounds, but some people lost 32 pounds, while others gained 4 pounds. Those who lost the least weight also reported more hunger and ate more on a given day near the end of the study than did those who lost the most weight.

“For some people it was clearly working, but for others it was counterproductive,” says Roberts.

It’s not just individual differences. Other factors, like temperature, might also matter. In a recent study, researchers assigned 16 overweight people to walk for 45 minutes on a treadmill when the room temperature was either 46º or 68º Fahrenheit.19 They ate more calories (1,300) at an all-you-can-eat buffet after walking in the cold temperature than after walking in the typical indoor temperature (1,170 calories).

“You need to keep doing exercise for your health, for preventing disabilities and problems in old age,” says Roberts. “But for most people, exercise is not the solution for losing weight.”

Bottom line: Exercise when you can, but don’t count on it alone to lose—or keep off—extra pounds.


1 Lancet 378: 826, 2011.

2 Am. J. Clin. Nutr. 95: 989, 2012.

3 J. Clin. Endocrinol. Metab. 97: 2489, 2012.

4 Int. J. Obes. 34: S47, 2010.

5 Circulation 129 (25 Suppl 2): S102, 2014.

6 Am J. Clin. Nutr. 96: 229, 2012.

7 Proc. Natl. Acad. Sci. 107: 18226, 2010.

8 Cell Metab. 17: 644, 2013.

9 JAMA Intern. Med. 173: 1292, 2013.

10 Diabetes 63: 2356, 2014.

11 Am. J. Clin. Nutr. 95: 1003, 2012.

12 J. Clin. Invest. 119: 1322, 2009.

13 Am. J. Clin. Nutr. 95: 283, 2012.

14 Int. J. Sport Nutr. Exerc. Metab. 22: 139, 2012.

15 Brit. J. Nutr. 111: 372, 2014.

16 Obesity 22: 325, 2014.

17 PloS ONE 2014. Doi:10.1371 journal.pone.0109849. 18 Int. J. Obes. 32: 177, 2008.

19 Med. Sci. Sports Exerc. 47: 49, 2015.

This article is based on content from the Nutrition Action Healthletter, originally published in April 2015. Click here to subscribe.

diet to improve high blood pressure About the Author.
Bonnie Liebman, director of nutrition, has been with the organization since 1977. She holds an M.S. in nutritional sciences from Cornell University. Liebman has been the key link in formulating our policies on diet and health.…More

3 Replies to “8 Big, Fat, Weight Loss Myths”

  1. But if you take a restaurant meal and cut it into 1/2 or 1/3 and take home 1/2 or 2/3 to eat another time what have you accomplished weight, health, and financially?

  2. It’s not easy to lose weight, but it is possible. I lost over 60 lbs over 3 years and it took diligence, grit and and determination. Have I back-slid? Yes, by about 15 lbs but I am not giving up the fight. This quote inspires me: “The first step toward getting somewhere is to decide that you are not going to stay where you are” J.P. Morgan
    Dieting is a mental game and I choose to focus on the positive outcomes rather than let distracted by how hard it is.

  3. Very frustrating that you did not include several of the charts and calculators in the online article. I wanted to share this article with my weightloss group but without the charts, I can’t. Disappointed.

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