Dietitians Debunk 6 Calorie Myths

Calories are a unit of energy that your body needs in order to do anything – move, digest food and even breathe. But is a calorie you eat equal to a calorie you burn? Unfortunately, it’s not as straightforward as you may have been led to believe. Below you’ll find six common calorie myths dispelled by registered dietitians.

Myth: All calories are always completely absorbed.

When you eat food, your body digests – or breaks down the food — with your teeth and enzymes. Once the food is broken down enough, it gets absorbed into the bloodstream and dispersed throughout the body where it’s needed. However, according to Maggie Moon, M.S., R.D., Los Angeles-based registered dietitian and author of The MIND Diet: 2nd Edition, “It’s a myth that the body absorbs 100-percent of the calories we eat.”

Moon explains that digestion is complex and calorie absorption isn’t always straightforward. “Clinical studies have proven that the body digests 21 to 32 percent fewer calories than what may be on the nutrition label for whole plant foods with strong cell walls like almonds and walnuts.” Moon also explains that eating whole foods is important since the more peeled, chopped, refined or ground a food is, the more rapidly its calories are absorbed. According to Olivia Thomas, M.S., R.D.N., Director of Nutrition Innovation and Implementation at Boston Medical Center, this is because “chopping, grinding or blending starts the digestive process mechanically, breaking down cell walls and making the energy in the food more bioavailable, or easier for the body to absorb. So even if the ingredients, portion size and calorie count on the label are identical, research shows the calories your body actually absorbs can vary significantly depending on how the food has been processed.” Thomas warns that this isn’t a reason not to eat any pre-processed foods like almond butter or almond flour. Rather, it serves as a reminder that “calories in verses calories out” isn’t a perfect equation.

Myth: Calories in verses calories out is the best way to think about weight loss or gain.

On paper, eating more calories than you burn (to gain weight), or burning more than you eat (to lose weight), makes sense. It’s also a rough estimate that a pound of fat equals 3,500 calories. However, according to Seattle-based Dr. Ginger Hultin D.C.N., R.D.N., C.S.O., author of Meal Prep for Weight Loss 101, “Human metabolism is so much more complex than calories in verses calories out.” There are numerous factors that play a role including age, gender, body composition (how much body fat verses muscle mass you have), hormones and genetics, says Hultin. “The way that I approach a client, who is, say, a 25-year-old female athlete verses a 70-year-old retired male client with diabetes is going to be very different. As a registered dietitian nutritionist, I know that there’s a lot more at play for both of these clients than simply burning or consuming 3,500 calories to meet their goals of losing or gaining a pound of fat mass.”

Myth: Eating much fewer calories is the fastest way to lose weight.

Although you may think that slashing calories can dramatically boost weight loss, Bonnie Taub-Dix, R.D.N., host of the Media Savvy Podcast, creator of newsletter Better Than Dieting and author of Read It Before You Eat It: Taking You from Label to Table, quite the opposite can be true. “When you eat too little, your body may go into a kind of ‘conservation mode,’ slowing your metabolism and holding onto fat as a survival response,” explains Taub-Dix. “Sure, you might lose weight at first, but that loss could come from a loss of water or muscle, and not the fat loss you’re shooting for.” Taub-Dix says that over time, this caloric restriction can backfire, ultimately causing you to then overeat and gain back whatever weight you may have lost, and sometimes even more.

Myth: All calories are created equal.

While a calorie is technically a unit of energy, the source of those calories matters, says Lauren Manaker, M.S., R.D.N. author and owner of Nutrition Now Counseling. “For example, 200 calories from a sugary soda will impact your body differently than 200 calories from a handful of walnuts. Foods high in protein, fiber and healthy fats take longer to digest, keep you full longer and provide sustained energy, unlike sugary low nutrient density foods that may impact blood sugars negatively and don’t provide micronutrients – which we need in order to function properly.” So, while calories are important, the quality of those calories plays a huge role in overall health and weight management.

Myth: You need to cut calories from a specific macro to lose weight or prevent weight gain.

“There are three macronutrients including fat, carbohydrates and protein – and we need them all!” says Hultin. Many people fear calories from fat thinking that eating fat leads the body to accumulate fat, or they fear calories from carbohydrates, assuming that eating bread, pasta or certain fruits like bananas causes weight gain, when that’s not actually the truth, explains Hultin. “Scientific evidence clearly shows that a balanced diet that offers protein foods, high-fiber carbohydrates and heart-healthy fats are all important and that a diet that includes all three is critical for human health.” In addition, taking in all three macronutrients is how you get micronutrients like vitamins and minerals.

Myth: Calories don’t matter.

Calories certainly matter when it comes to weight loss, weight maintenance or weight gain, but other things matter, too. According to Keith T. Ayoob, Ed.D., R.D., Associate Clinical Professor Emeritus in the Department of Pediatrics at Albert Einstein College of Medicine and owner of Cut to the Chase Nutrition, the source of your calories matter as well. “A 2017 evidence-supported published perspective paper concluded that while there are many paths to weight loss, total calorie intake, meaning creating a sustained calorie deficit, was the determining factor for addressing obesity,” explains Ayoob. However, you still need to find a path that includes foods that meet your individual needs, likes and dislikes, and need to balance foods to have a healthy diet. According to Ayoob, weight loss is annoying, but it works. Many people don’t realize that once you get to weight maintenance, that’s where the action is, and it requires changing your relationship with food. “That takes time, so use the time spent in that calorie deficit to zero in on eating styles and behaviors that will work for you. And don’t forget to get physical, in whatever way you can,” says Ayoob.