Are Some Calories Better Than Others? Yes, Suggests New Research

All foods have the potential to make us obese if we eat enough of them, but some calories—especially those from sugary drinks—could be more harmful to our health than others, scientists have warned.

Last year, 22 researchers posed a question: Are all calories equal with regards to effects on cardiometabolic disease and obesity? Cardiometabolic disease is the umbrella term for chronic conditions such as diabetes, heart disease and strokes.

The team wanted to understand, for instance, if 10 calories from a french fry and 10 calories from an apple were equal in how they affected the body, even though they contain the same amount of energy. To answer the question, they carried out a review of current studies relating to how diet can lead to cardiometabolic diseases.

Researchers believe that sugar-sweetened beverages raise the risk of cardiometabolic disease. Getty Images

The researchers highlighted the fact that most Americans consume too many calories. Some 69 percent of U.S. adults are overweight, and new estimates suggest almost 40 percent are obese.

Calories from saturated fat and sugar-sweetened drinks were linked with cardiometabolic diseases, regardless of whether a person gained weight, according to the paper, which was published in the journal Obesity Reviews.

Kimber Stanhope, a research nutritional biologist with the School of Veterinary Medicine at the University of California, Davis, and the study's lead author, said in a statement, "What's new is that this is an impressive group of scientists with vast experience in nutrition and metabolism agreeing with the conclusion that sugar-sweetened beverages increase cardiometabolic risk factors compared to equal amounts of starch."

The research also indicated that eating polyunsaturated fats present in some nuts, seeds and vegetables oils was linked with a lower risk of disease, compared with equal amounts of saturated fats, such as those found in red meat. However, dairy products such as yogurts and cheese, which often contain saturated fats, were linked with a lower risk of developing cardiometabolic conditions.

The authors also concluded that the sugar substitute aspartame does not cause weight gain in adults. Following fears the substance could cause diseases such as cancer, health officials agree that 40 milligrams per 1 kilogram of body weight is the acceptable daily intake of aspartame.

"If you go on the internet and look up aspartame, the layperson would be convinced that aspartame is going to make them fat, but it's not," said Stanhope. "The long and short of it is that no human studies on noncaloric sweeteners show weight gain."

She continued, "We have a long way to go to get precise answers on a lot of different nutrition issues. Nevertheless, we all agree that a healthy diet pattern consisting of minimally processed whole grains, fruit, vegetables and healthy fats promotes health, compared with the refined and palatable typical Western diet pattern."

The paper comes after officials in San Francisco failed to force soda companies to warn consumers against the risks of obesity, diabetes and tooth decay on soda labels, after a court ruled in favor of organizations including the American Beverage Association.

Frankie Phillips, a qualified dietitian and spokesperson for the British Dietetic Association, told Newsweek the study builds on existing evidence which shows some foods have different effects on metabolic health.

Asked what the wider population should take from studies on diet and nutrition in general, she said: "The overall message rarely changes—eat a variety of foods and in moderation, using appetite as a guide. Specifically we need to be careful how much salt, saturated fat and sugar we have as these are currently too high."

Updated: This article has been updated with comment from Frankie Phillips.