UNIVERSITY PARK, Pa. — Each year, the Volumetrics plan has consistently been recommended when people have looked to U.S. News & World Report rankings for advice on diets to improve their health or manage their weight.

This year, Volumetrics is ranked as a top-10 diet in 10 categories, including best overall, best weight loss diets, best fast weight-loss diets, easiest to follow, best for healthy eating, best for diabetes, best heart-healthy diets, best for bone and joint health, best family-friendly diets, and best plant-based diets.

The plan, developed by Barbara Rolls, Helen A. Guthrie Chair in Nutrition at Penn State, recommends consuming foods that are low in calorie density, so that people eat a volume of food that satisfies their hunger without consuming more calories than their body needs.

The principles and process of Volumetrics have been defined over the course of three books and many scientific publications, but in 2023, Volumetrics will also be adapted into a six-part webinar series by Penn State Extension. "The Volumetrics Weigh of Life: Weight Management Plan" presents fundamental weight management principles and emphasize sustainable eating patterns for lifelong weight management. Each of the six classes will provide calorie density lessons, food demonstration videos, examples of Volumetrics food choices and interactive learning opportunities through small group discussions.

The webinar series won first place for innovation at the 2022 national annual meeting of the National Extension Association of Family and Consumer Sciences.

“Over the years, Penn State Extension has offered weight-management services, and they thought the ideas in the Volumetrics books would be useful to the general public,” Rolls said. “I’m just so excited that more people will learn the fundamentals of building a healthy diet.”

Rolls, also director of the Laboratory for the Study of Human Ingestive Behavior in the College of Health and Human Development at Penn State, said the goal of her program is to help people sustain healthy weight over a lifetime. She stresses there are no “quick fixes” or miracle diets; weight loss and healthy eating are lifetime commitments.

“Fundamentally, it is not a competition of which diet is the best,” she said. “It is about understanding the principles of why we eat what we eat and why we overeat, and Volumetrics offers those insights. You need to find an eating plan that you enjoy and that you are going to sustain. You are eating not just for weight management but for life-long health.”

Multiple research studies by Rolls and others have found that people tend to eat a similar volume of food every one or two days. Volumetrics encourages the inclusion of foods that contain a lot of water because water is heavy and calorie-free. This is why water-rich foods like vegetables, fruits and broth-based soups can be beneficial to people trying to manage their weight.

“If people are eating a consistent weight of food, then the calories in each ounce or bite are going to make a big difference,” Rolls said. “We’ve done studies that show you can reduce the density of calories in food by 25% to 30% without compromising taste, by tweaking the ingredients.”

Rolls emphasized the importance of repeated, daily food choices. She noted many beverage options are available and that people could try to identify a low-calorie drink that they enjoy if they frequently consume high-calorie beverages. Similarly, she recommends the use of low-calorie condiments; for example, spicy mustard could be used in lieu of mayonnaise on sandwiches.

Rolls encourages anyone who is interested in healthier eating to begin by reflecting on potential changes in their current diet, though not in a restrictive way.

“Volumetrics isn’t about restrictions or giving up your favorite foods. It is about modifying them to maintain taste while reducing unneeded calories,” Rolls said. “I encourage people to look at the foods they’re eating and then figure out ways to tweak them so they’re healthier and have fewer calories. We have shown in many experiments that you can cut down on the fat and sugar and enhance the flavor with herbs and spices.”