What is the Volumetrics diet — and should you try it?

No foods are off-limits with this eating plan that’s big on fruit, veggies, whole grains and broths.
Close-Up Of Hand Holding Food
The Volumetrics diet supports beneficial diet and lifestyle changes and its efficacy is backed by science.Getty Images

Deprivation is often the deal breaker of many diets. Weight loss on restrictive plans may occur in the beginning, but humans are wired to return to their comfort zones. In 2000, a diet called Volumetrics emerged as a way to enable weight loss without the additional challenge of feeling like you’re giving something up.

What is the Volumetrics diet?

Created by Barbara Rolls, the author of several books on the Volumetrics diet, this eating plan is structured around foods that are lower in calories yet high in nutrients like fiber-rich cruciferous vegetables, whole grains and water-based broths. The theory is that this combination of low-energy-dense but high-nutrient-dense foods could make you feel full on fewer calories.

The plan is divided into four groups based on how nutritious the foods are and how many calories they provide and it offers a road map for portions, which is essentially to eat more of groups 1 and 2 and taper off portions and frequency in groups 3 and 4.

Group 1 includes non-starchy fruits and vegetables, nonfat milk and broth-based soups that are considered “free foods.” Groups 2 (lean sources of meat, starchy plants like legumes, and starchy fruits and vegetables) and 3 (salad dressing, cheese and pizza) have foods that must be carefully portioned. Lastly, group 4 includes crackers, chips, chocolate candies, cookies, nuts, butter and oil — all foods you should minimize. In addition to the food groupings, Rolls recommends about 30 minutes per day of physical activity.

Maya Feller a Brooklyn-based dietitian and author of “The Southern Comfort Foods Diabetes Cookbook,” says the Volumetrics diet is truly "a ‘no diet’ diet.” A key strength of the eating plan, she points out, “is its simplicity.” Feller adds that since the Volumetrics diet “focuses on types of foods that promote satiety, it may be easier for individuals to follow the diet and remain motivated during the first days, which can be the hardest psychologically.”

The science behind the diet

The Volumetrics diet supports beneficial diet and lifestyle changes and its efficacy is backed by science, so it’s generally regarded as a sound eating plan, says Feller. In 2014, a small randomized control trial analyzed various methods for weight loss, including the Volumetrics diet approach of consuming low energy dense foods. The study included 132 participants and while all participants lost weight, those following a Volumetrics approach showed superior results in weight loss and were able to maintain it more effectively compared to the other groups. Additional research with a larger sample size of 9551 adults found that individuals following low energy dense eating patterns had significantly lower BMI, smaller waist circumference and were less likely to be obese.

Is the diet sustainable?

Julia Zumpano, a dietitian with the Cleveland Clinic, says that “the diet was designed to provide more sustained long-term weight loss,” adding that “there is certainly potential for short-term weight loss, especially if you significantly minimize category 3 and category 4 for the short term” and adhere to exercise guidelines. Zumpano likes that the diet focuses on vegetables, fruits and foods that provide fiber, fullness and satiety. Like Feller, Zumpano believes the plan is “simple to follow, suitable for dietary restrictions and various dietary preferences and backed by research.”

There are, however, a few downfalls to the diet. Feller cautions that the meal planning aspect could be challenging and says that “for people who don't cook at home, preparing all meals may be a barrier.” She points out that eating out is allowed on the diet. But, she says, “navigating a restaurant menu may be challenging when eating low energy density foods.” She also mentioned that “when following any diet from a book, the person misses the individualization and guidance that comes from working with a registered dietitian.”

Zumpano further adds that “watching portion sizes for category 3 and minimizing intake of category 4 is vague and self-directed, which can lead to consuming higher quantities of these foods than intended by the diet.” In fact, a 2020 animal study found that highly palatable foods (as found mostly in category 4) impacted pleasure receptors in the brain that led to overeating and obesity. This could counteract the effectiveness of the plan and force Volumetrics dieters back into their comfort zones. Finally, Zumpano cautions that the diet “may not meet the needs of those that would benefit from more structure.”

Should you try the Volumetrics diet?

If you’ve struggled with restrictive diets in the past and are seeking a more phased in approach, then the Volumetrics diet may be a good fit. However, both Feller and Zumpano believe that success with this diet ultimately depends on the individual.

The Volumetrics diet is one of the smarter and safer approaches that you can consider. Working with a dietitian or physician to structure a more personalized approach — one that involves a plan for portion control in groups 3 and 4 and meal planning — could be the healthy eating solution you’ve been looking for.