Top 7 Weight Loss Myths Debunked

The topic of weight loss has a knack for making headlines. As a hotly debated subject over the years, it’s not hard to find strong opinions about what does or doesn’t work to shed those pounds.

According to the CDC, three-quarters of Americans are overweight or obese. But what is a healthy weight anyway? It might not be as cut and dry as you think. 

With so much misinformation and many conflicting viewpoints out there, who and what can you believe? Is science any closer to the definitive answer of how to achieve a lasting healthy weight?

Are you ready to explore some of the common weight loss myths out there? Let’s get into it! 

Don’t Fall For It: 7 Weight Loss Myths Debunked

Myth 1: Eating Less Will Always Help With Weight Loss

If you just eat less, you’ll lose weight, right? Not exactly.

Prolonged low-calorie diets may lead to metabolic changes that could cause the body to adapt to the calorie restriction and prevent further weight loss. In some cases, under-eating may even result in weight gain. 

Breaking things up with intermittent fasting is the solution some have suggested to counter the effects of the above. Intermittent fasting is a diet approach that cycles between periods of fasting and periods of unrestricted eating.

This might include a pattern of fasting for 14 to 20 hours, alternate day fasting, or fasting spanning more than one day. However, current research does not consistently show that intermittent fasting is superior to continuous low calorie diets for weight loss success.

Here’s what studies show so far:

• A randomized controlled trial that tracked 100 obese adults for one year did not find intermittent fasting (with alternate day fasting) to be more effective than daily calorie restriction.
• A one-year randomized trial also did not find intermittent fasting (16:8 method) more beneficial than calorie reduction without a restricted eating time. 
• Studies have also shown that prolonged periods of food deprivation may increase cravings and make overeating more likely when food is reintroduced.

So what should you do instead? Eating patterns that favor a moderate time-restricted shift to an overall earlier eating window may provide some benefit for weight and metabolic health compared to eating patterns that follow a later eating window.

Some studies have shown morning loaded intake (eating a big breakfast) may improve appetite regulation through the day. Results from another study also suggest that an early eating window may be associated with greater weight loss. However, to find the right length of eating/fasting window and appropriate caloric intake for your individual needs, it may be best to work one-on-one with a dietitian who can support you. 

Myth 2:  Low-Carb Diets Will Help You Lose the Most Weight

Low carbohydrate diets have held many names through the years, such as The Atkins Diet, The South Beach Diet, or the Keto Diet, among others. 

Some believe that restriction of carbohydrates causes hormonal changes that promote body fat loss more so than dietary fat restriction. However, this idea doesn’t always pan out as expected, and research is conflicted when it comes to these diets and weight loss. 

The impact of low-carb diets on weight and metabolic health may depend on things such as:

• Your current and past medical conditions 
• Your dietary quality overall beyond just the number of carbs (including protein intake).

Low-carb diets may cause a more rapid initial weight loss for some people, but many studies have shown that overall weight loss over a longer period of time is similar to other diets involving caloric restriction alone.

Researchers have also debunked the idea that your body burns more body fat while on a high-fat and low-carb ketogenic diet, compared to a higher-carb, low-fat diet. 

However, if someone has diabetes or insulin resistance, there is some evidence that a lower carb approach may be more beneficial for multiple metabolic markers, including blood glucose, than simply reducing calories alone.

Other studies reveal that higher intake of added sugar is itself an independent risk factor for obesity. In this case, low-carb diets may inadvertently address that variable, though they may not always be necessary to achieve the same benefit.

Simply reducing sugar alongside including healthier carbohydrates from whole food sources within a balanced diet may have equal health benefits for some. 

Myth 3: Counting Calories is the Best Way to Lose Weight 

Traditional theories of weight loss have focused on the model of “calories in versus calories out,” or the Energy Balance Equation. This equation is based on the belief that eating fewer calories than you burn is how you lose weight.

But is this formula really all you need to reach your weight loss goals? Current research suggests perhaps not. 

Scientists now believe that many of the energy balance equation applications are over-simplified and inadequate to understand weight loss.

How Calorie-Counting Can Fail

• Different foods with the same exact amount of calories can have dramatically different metabolic impacts on your body. 
• Caloric need estimates aren't always as accurate as you might think. According to the Academy of Nutrition and Dietetics, research studies have indicated many of the formulas for calculating caloric needs are about 90 percent accurate only about 60 percent of the time.
• Our hormones influence a lot about our weight. Our hormone levels (thyroid hormone, insulin, cortisol, etc.) can sometimes be negatively impacted by how we eat or other lifestyle factors, beyond just calories. 
• Calorie-focused approaches lack details about macronutrient and micronutrient balance and the ideal ratios of nutrients that our unique body may require for optimal metabolic function. 

Myth 4: You Can “Burn Off” Poor Food Choices With More Exercise

While exercise has many benefits as part of a healthy lifestyle, it won’t offset poor nutrition. Furthermore, if you fail to properly fuel your workouts, you might actually do more harm to your metabolic health than good.

Exercising without proper nutrition or fueling support can lead to increased risk for injuries, fatigue, and higher metabolic stress loads that work against weight loss goals over time. 

Studies looking at energy deficiency in sports-related activity found several concerning risks associated with under-fueling, including:

• Lower resting metabolic rate 
• Dysregulated hormone levels
• Poor bone health

Healthy eating is key, as your macronutrient and micronutrient intake both contribute significantly to metabolic function. Imbalances in these may lead to changes in body composition independent of exercise. 

Dietary intake, including the impact of diet on glucose regulation—can also impact hormones such as insulin that impact weight in ways exercise may not fully offset. 

You may consider consulting a registered dietitian to learn more about what dietary needs you should be meeting.

Myth 5: There’s Nothing You Can Do to Change Your Metabolic Rate 

There are several predictors of how fast or slow a person’s metabolic rate will be. These include:

Having a higher metabolic rate means your body uses food for fuel (instead of storing it as fat) more quickly. But how can you positively or negatively influence your metabolic rate?

On one hand, studies from the cohorts from the Biggest Loser have shown that rapid and extreme weight loss from certain methods may slow metabolic rate over time. This may then lead to more extreme restrictions being required over time to keep the weight off.

On the other end of things, some studies show that increases in lean muscle mass improve insulin sensitivity, glucose regulation, and can increase metabolic rate modestly. This is a positive! 

At this time, additional studies are still needed to fully clarify the relationship between body composition, physical activity, energy regulation, and weight maintenance. However, we have good evidence to suggest that it might be a good idea to avoid over-restriction and aggressive weight loss approaches, properly fuel your workouts, and focus on building that lean muscle mass!

Myth 6: Weight Loss Supplements Are Mostly Safe and Effective

Unlike drugs, dietary supplements do not require premarket review or approval by the FDA. This means that many supplements that are ineffective, dangerous or untested may still make it to market. 

Products such as weight loss tea, weight loss gummies, or weight loss smoothies can contain a wide range of ingredients, and the amount of scientific information available on these ingredients varies greatly. In some cases, the evidence supporting their use is incredibly limited and/or of poor quality. 

To add to the confusion, most weight loss dietary supplements contain multiple ingredients. This makes it far more difficult to isolate the effects of each ingredient and understand the effects of the combination as a whole. 

For detailed information on some popular weight loss shakes or supplements, visit the NIH’s Office of Dietary Supplements weight loss page.

Myth 7: Healthy Weight Loss Should Happen Fast  

Impatience is a common feeling during the process of losing weight. Frustration may drive you to reach for whatever approach promises the fastest results.

But fast results don’t always mean lasting or healthy results. In some cases, fast results that come from fad diets or “cleanses” are not only unsustainable, but may pose added risk to health over time. 

Some studies show that crash diets are more likely to lead to weight regain. And as you’ve learned from above, certain more extreme approaches to crash dieting may come with longer-term negative health consequences, including having a harder time keeping weight off.

Rapid weight loss may also come with greater risk for things like:

• Gallstones
• Loss of lean muscle mass

Instead of seeing the absence of a quick fix as a let-down, try to see it as an opportunity to explore areas of your metabolic health that may need some extra attention and care. 

As you take the time to dial in a customized approach, you might notice additional benefits such as improved energy, exercise performance, or sleep quality.

Are You at a Healthy Weight?

A healthy weight is a number linked to a relatively lower risk of weight-related health conditions. Each person’s healthiest weight will depend on things such as:

• Sex
• Age
• Genetics, including body frame and structure
• Medical History
• Lifestyle and behaviors

The CDC places weight status into the following categories:

That being said, assessing BMI alone also has many limitations, such as:

• Not distinguishing between fat, muscle, or bone mass
• Not identifying different fat distribution patterns in the body, a known independent risk factor for poor metabolic health outcomes

Additionally, your weight alone won’t tell you everything about your metabolic health, including your risk for diabetes and heart disease. 

Starting a Weight Loss Journey

Your weight and how your body maintains, gains, or loses weight over time depends on a complex set of interactions among genetic, behavioral, and environmental factors. 

The truth is that what works for someone else may not work for you, and vice versa. And that’s okay! 

What’s the Best Diet for Weight Loss?

The best diet for weight loss depends on your individual needs! So, as you begin your weight loss journey, here are some important reminders:

• Sustainable lifestyle changes tend to be more effective than “crash diets”. If you want lasting results, be prepared to build healthier habits that feel sustainable for the foreseeable future.
• Set realistic goals that take into account what a healthy weight is for you personally. Team up with a professional, such as a dietitian, who can help guide you.

Body recomposition goals (losing body fat and gaining muscle) may have unique strategies beyond weight loss goals alone.