Morgan is a doctoral candidate in the field of clinical nutrition and nutritional neuroscience, having received her bachelors degree from Central Washington University.
The Volumetrics Diet aims to keep dieters full on low-Calorie foods. Dieters eat three meals, two snacks, and dessert each day, focusing on foods that are low in Calories per their relative volume. The Volumetrics plan organizes foods according to groupings designed by Rollins. Foods are assigned to these groups according to their Caloric density. Group 1 foods have the lowest density (and therefor, fewest Calories per serving size), while Group 4 foods have the highest density (highest number of Calories per serving size). By cuing dieters to focus their diet on Group 1 and 2 foods , moderating group 3 foods, and sparingly incorporating group 4 foods, dieters take in fewer Calories overall than they would on a typical diet, and therefore lose weight while thwarting the hunger that derails many dieters on other plans.
Barbara Rolls, PhD pioneered the Volumetrics Plan in her book The Ultimate Volumetrics Diet, after theorizing that people tend to eat the same amount of food (in volume) rather than the same amount of Calories each day. Therefore, by focusing on food that is low in Calories but high in volume, weight could be lost without sacrificing satiety (the feeling of fullness).
The Volumetrics plan is a fairly simple plan to stick to, as no foods are eliminated, and dieters rarely feel hungry thanks to the high consumption of fresh vegetables and “group 1” foods.
The only cost to dieters is the Volumetrics guidebook and groceries; grocery costs will depend on what specific items dieters purchase, and in what forms they purchase them (fresh, frozen, canned, etc).
Depending on the dieter’s culinary inclinations, the Volumetrics time cost can be prohibitive or enjoyable. As the Volumetrics plan focuses on vegetables, fruit, and lean proteins, dieters can choose to make quick salads and lettuce wraps, or snack on cut fruits and veggies to save time, or spend time creating elaborate meals. Overall, the Volumetrics plan doesn’t take much more time that the diet consumed by many Americans.
Volumetrics is a very safe diet overall, as it prioritizes healthy, whole foods that are low in Calories and high in nutrients. However, for diabetics, prediabetics, or dieters with insulin resistance, it's important to consult a doctor to determine what foods on the Volumetrics plan should be avoided or prioritized to help control blood sugar.
This diet is not widely debated, as it is considered to be a safe plan that encourages the consumption of fresh, healthy foods without eliminating food groups.
Benefits: Dieters who abide by the volumetrics plan will likely enjoy the relatively simple food grouping strategy, which helps create an awareness of high-Calorie foods. Dieters will also benefit from increased vegetable consumption.
Downsides: Dieters may struggle with cravings and struggle without emotional support and behavior modification tools. Many dieters already know what they should be eating, but struggle with the behavioral change it takes to consistently achieve that without support.
The Bottom Line: Volumetrics is overall a very healthy way of eating that emphasizes many good choices over bad, but may not promote weight loss as effectively as Calorie-counting, which allows dieters to eat what they like best (within Calorie guidelines.) and still lose weight. If dieters are pleased by the Volumetrics-style eating plan and are able to stick to it long-term, they will likely lose weight doing so.