The Volumetrics diet plan—developed by Barbara Rolls, professor of nutritional sciences and Helen A. Guthrie Chair in Nutrition at Penn State—ranks as a No. 2 weight loss plan in U.S. News & World Report's Best Diets of 2018.

The annual “Best Diets” list by U.S. News & World Report creates in-depth profiles of common diets and eating plans across a number of different health and fitness goals.

A panel of experts in diet, nutrition, obesity, food psychology, diabetes, and heart disease review the profiles, and rate them in seven categories: how easy it is to follow, its ability to produce short-term and long-term weight loss, its nutritional completeness, its safety, and its potential for preventing and managing diabetes and heart disease.

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 Volumetrics has made the U.S. News & World Report’s top 10 diet lists since 2011 when the ratings began.

Rolls said the goal of her program is to help people sustain a healthy weight over a lifetime. She stresses there are no “quick fixes” or miracle diets; weight loss and healthy eating are lifetime commitments.

“Volumetrics is about being educated for life to make decisions about your eating,” she said. “The science supports Volumetrics. Research shows the importance of the food you eat, rather than how much, in losing and maintaining weight loss. I hope these rankings will inspire people to make healthy and sustainable weight loss a priority.”

The approach focuses on feeling full on fewer calories. By substituting low-calorie dense foods, such as fruits and vegetables, for high-calorie dense foods, participants can manage hunger while consuming fewer calories. Followed long-term, the goal is sustainable weight management for people of all ages, Rolls said.

Under Volumetrics, food is divided into four categories in which participants are given guidance on the amounts they should eat.

For example, in Category 1, participants are encouraged to eat large portions of very low-calorie density foods, such as nonstarchy fruits and vegetables and broth-based soup.

Category 2 choices also are meant to make up a large portion of participants’ diets, and include foods like starchy fruits and vegetables, grains, legumes and low-fat meats, dairy, and fish.

With Category 3 foods, such as breads, desserts, and higher-fat meats, portion control is needed.

Category 4 choices, which should be kept to a minimum, include high-calorie density foods, such as crackers, chips, and cookies.

Additionally, the plan does not involve cutting out any food groups, and participants can keep eating their favorite foods, with a few tweaks.