From extreme juice cleanses to supposed miracle supplements, some folks seem willing to try just about anything to lose weight. However, experts say many of these fast-track methods are based on myths, since weight loss is the result of consistently taking in fewer calories than you expend over time and making smart dietary choices.
According to Artur Viana, MD, clinical director of the Metabolic Health & Weight Loss Program at Yale Medicine, one of the most popular weight loss myths is that all you have to do is exercise more and you'll lose weight.
"Exercise is fundamental to a healthy lifestyle, weight loss, and weight maintenance, but it has to come with a change in diet as well," Viana says.
Below, experts in diet and exercise debunk some of the most common misconceptions about weight loss.
Your body doesn't metabolize all foods the same way. And how quickly you digest something can affect insulin levels, blood sugar spikes, and fat storage.
For example, compare 100 calories worth of cake to 100 calories of carrots. The calorie amount is the same, however, the cake is made with refined carbohydrates whereas carrots contain more fiber and nutrients.
This difference is important because your body digests the cake more quickly. This floods your system with glucose, spiking blood sugar and insulin levels in the process, which can promote fat storage.
Carrots, by contrast, are digested more slowly which means less glucose in your blood. This helps to maintain healthy blood sugar levels and it can also keep you fuller, longer, which may prevent overeating.
So, while 100 calories worth of cake and 100 calories worth of carrots provide the same energy output, one is clearly superior for weight management over the other, says exercise physiologist Joel Seedman, PhD.
Viana also says processed foods don't send the same satiety signals to your brain as whole foods do, meaning you're more likely to overeat and thus, gain weight.
Research suggests that it's what you eat and how much that matters, not necessarily what time you eat.
What the research says: A large 2016 study found no link between eating dinner past 8 p.m. and weight gain in children. However, a 2008 study revealed that people who ate between the hours of 11 p.m. and 5 a.m. consumed roughly 500 more calories per day and gained more weight than those who only ate during daytime hours. However, other research has shown that mealtime may affect glucose intolerance and reduce fat utilization, especially if you're habitually eating a late dinner.
The takeaway is that eating at night may make you gain weight if it causes you to go over your daily calorie budget, says Andres Ayesta, MS, a registered dietitian and certified strength and conditioning coach.
Carbohydrates are often billed as the enemy when it comes to weight loss, but a 2018 study revealed that adults who followed a low-carb diet lost the same amount of weight, on average, as those who followed a low-fat diet.
Not all carbs are created equal, though. Whole grains pack more fiber than refined carbs, meaning they're metabolized more slowly and don't cause big insulin surges.
In fact, a 2017 study found that people who ate a diet with enough whole grains to meet the recommended dietary allowance for fiber burned 100 more calories per day, in part due to a slight increase in their resting metabolic rate, when compared to people who ate refined grains with little fiber.
Ayesta says that fat contains more calories per gram than protein and carbohydrates, which means fat is much easier to overconsume.
However, a 2019 review revealed that the Mediterranean diet which entails getting about 35% to 40% of your calories from heart-healthy fats may prevent increases in weight and waist circumference in non-obese individuals.
Researchers noted that a Mediterranean diet supplemented with extra virgin olive oil, for example, can decrease total body weight and BMI.
A 2016 study revealed that people without Celiac disease are buying gluten-free products because they believe they're a "healthier option."
In reality, "many processed gluten-free products are actually more calorie-dense than their gluten-containing counterparts because they may contain more fat and sugar," says Viana.
A 2017 review found that overall, gluten-free foods had more saturated fat, sugar, and salt, and less protein and fiber than regular foods. Specifically, gluten-free bread and flour products tended to contain high fat and sugar in comparison to their gluten-containing counterparts.
When it comes to weight loss, eating breakfast is a mixed bag. Some research indicates it can help with weight loss while other research suggests the opposite. For example, a 2018 review found no strong evidence to support the idea that eating breakfast helps you to lose weight.
Viana says the only case in which eating a large breakfast might be beneficial is if it helps you to eat fewer calories later in the day.
According to Harvard Medical School, a 155-pound person burns roughly 372 calories while running an average 10-minute-per-mile pace for 30 minutes, and about 112 calories lifting weights for the same amount of time.
Even though cardio workouts may burn more calories in the moment than strength training, at least one small study has shown that you may burn more calories in the hours after lifting weights, because your metabolism may stay elevated longer.
Seedman says that when it comes to losing weight, the ideal exercise regimen includes a combination of both cardio and resistance training.
Studies have shown that many exercisers resort to "compensatory behaviors" after working out that offset the calories they expend. For example, a 2009 study of postmenopausal women, who were either overweight or obese, revealed that participants seemed to increase their food intake after working out on a treadmill or exercise bike, either because they felt hungrier or because they thought they burned off a lot of calories.
The idea behind small, frequent meals is that it helps better control hunger and keeps your metabolism up throughout the day for easier weight loss. However, in practice, this isn't what happens, according to scientific research.
For example, a 2007 study examined two groups of people who consumed an equal number of calories per day: one that ate three meals with no snacks, and another that ate three meals and three snacks. By the end of the year-long experiment, researchers found no difference in weight loss between the two groups.
According to Seedman, meal size and frequency is a matter of figuring out which approach best fits your lifestyle and helps you to stay within your daily calorie budget.
While a juice cleanse may result in short-term weight loss, Viana says that's due to a severe calorie deficit one that's not realistic to uphold for more than a few days at most. Once you re-introduce solid foods, you're likely to regain any weight that was lost.
Ayesta also points out that you're mostly losing water weight with this strategy because drinking so much juice can cause you to urinate more often.
Dietary supplements aren't regulated by the Food and Drug Administration (FDA), and the FDA says that many of them do not live up to their weight-loss promises and may even contain dangerous hidden ingredients, such as chemicals contained in blood pressure medications and antidepressants.
Moreover, a 2004 review found no convincing evidence that dietary supplements help with weight loss.
Ayesta and Viana say that many of the persistent weight-loss myths stem from social media, the ever-changing realm of nutrition science, as well as the $71 billion weight loss industry, which is continually churning out new products to remain competitive.
The bottom line? If a weight-loss method sounds too easy or too good to be true, it probably is.
Weight loss is "a journey that requires patience, education, and consistency to yield
sustainable results," says Ayesta. "People don't have to follow strict rules and eliminate entire food groups simply to accomplish weight loss."
Rather than taking extreme measures, Viana advises focusing on sticking to an exercise regimen that includes both cardio and resistance training, and maintaining a diverse diet that emphasizes whole foods over processed ones.
Lastly, Ayesta says it's important to keep in mind that diets only work when they restrict calories, but the only way to keep that weight off is to make sure your dietary changes are sustainable over the long term.