Energy Density’s Link to Weight Loss

Calorie density of foods plays a role in weight gain and loss

(RxWiki News) The best way to lose weight appears to continue being the old-fashioned, tried-and-true method: reducing the density of calories that you eat.

The upshot of a recent report that surveys current research is that since eating too many calories will pack on pounds, eating a diet of foods with a low density of calories will help people lose and/or maintain their weight.

"Eat a low-calorie, well-balanced diet daily."

Study author Rafael Perez-Escamilla, PhD, a 2010 Dietary Guidelines Advisory Committee member and a researcher at Yale University, investigated 17 studies involving the energy density of diets and adults' body weight.

Energy density refers to the number of calories in a particular food, so one with a low energy density does not have a huge number of calories for its size.

The 17 studies were a mixture of randomized controlled trials and group studies that looked backward at group participants' previous behavior and outcomes without being part of a controlled experiment. The studies came from the U.S., South Korea and Brazil as well as France, Germany, the Netherlands, Denmark and several other parts of Europe.

Evidence from all but two of the studies showed a connection between lower numbers of calorie density in a diet and success with weight loss or maintenance, though not all the participants successfully kept off weight they had lost. Most studies also revealed a link between increased energy density and higher levels of weight in children.

"The conclusions reached in our review strengthen the recommendations in the Dietary Guidelines to consume such foods as fruits, vegetables, whole grains, and lean animal protein sources, which are generally lower in energy density, while lowering consumption of total fat, saturated fat, and added sugars, which increase the energy density of foods," Perez-Escamilla said.

The conclusions "also strengthen the focus on considering overall dietary patterns rather than simply targeting modifications to individual components of the diet," he said.

Perez-Escamilla said researchers are unsure about how energy density and a person's weight interact but that they believe eating less calorie-dense food can help people reduce their overall calorie intake and help make them feel more full.

The public health community should better explain what energy density is and how it relates to a person's body weight, Perez-Escamilla said.

"Guidelines for how to estimate energy density for different products based on food label information, how to decrease dietary energy density , and how to sustain weight loss benefits using lower energy density diets in the long term are needed," he said.

Eve Pearson, a registered and licensed dietitian in Fort Worth, Texas, said her work with clients has shown her that people want to be able to just cut out this or that food to lose weight when the best approach is to simply eat smaller amounts of food.

"When you cut out something, no matter what something is, it contains energy (calories.) They're essentially cutting out calories by eliminating whole food groups or macronutrients, which is not sustainable over time," she said.

A wiser method is to focus on portion size, Pearson suggests.

"They could start by eating half of the food they're served in a restaurant or fast food establishment and eating on a smaller plate at home and not going back for seconds," she said.

She added that being conscious of how many calories people drink rather than eat is important to consider as well.

The study appeared online April 3 in the Journal of the Academy of Nutrition and Dietetics.

Review Date: 
April 3, 2012