Aside from the fact that some commercial weight loss diets, such as the Nutrisystem diet, use overly processed and packaged foods rather than real food, most of these weight loss diet plans have exceedingly small portions.
While portion control can be an effective means of controlling caloric intake when trying to lose weight, if you have a big appetite or simply enjoy the feeling of eating, having a minuscule meal or tiny snack may not provide the satisfaction you need to feel like you have eaten.
The Volumetrics diet plan is an attempt to provide an alternative way to lose weight.
In this diet guide, we will discuss the Volumetrics diet plan, its principles, how to follow it, and potential pros and cons so you can decide if it is the right diet plan for you.
Lets jump in!
What Is the Volumetrics Diet?
The Volumetrics diet plan for weight loss focuses on the concept of eating more to lose weight.
Here, the term more doesnt refer to more calories per se but rather a greater amount or volume of food (hence the name volumetrics).
The volumetrics diet plan was developed by a nutrition and obesity researcher at Penn State University named Dr. Barbara Rolls, Ph.D.
Dr. Rolls created the Volumetrics diet plan as a way to help people feel psychologically or emotionally more satisfied when trying to lose weight due to the ability to eat larger portions with a fewer number of calories.
She co-authored a book on the Volumetrics diet called The Ultimate Volumetrics Diet: Smart, Simple, Science-Based Strategies for Losing Weight and Keeping It Off, which explains her research on the benefit of being able to eat more food while still losing weight.
The book also includes Volumetrics diet recipes and tips to help you stick to this eating plan.
For example, the 2022 U.S. News and World Report Best Diets ranks the Volumetrics Diet as the best diet for weight loss, fifth overall in Best Diets Overall, and fifth for Best Diets for Healthy Eating.1Best Diets Overall. (2019). Usnews.com. https://health.usnews.com/best-diet/best-diets-overall
What makes the Volumetrics eating plan one of the best healthy weight loss diets overall is the fact that foods that are voluminous yet low-calorie tend to be the most nutritious foods.
These healthy foods include veggies, fruits, and other whole, natural, unprocessed foods rather than packaged foods, foods with added sugars, or ultra-refined foods.
How Do You Follow the Volumetrics Diet Plan?
While you do not need to count calories on the Volumetrics plan, you are supposed to scale your portions and serving sizes and make your food choices based on the energy density groupings of foods shown below.
Rather than having small portions of energy-dense foods, a volumetric diet meal plan encourages the consumption of low-calorie foods that are bulky so that you can have a larger amount of food without consuming a lot of calories.
Therefore, the volumetrics diet plan relies on the concept of the calorie density of a food. By prioritizing foods that have a low energy density for the size or volume, you can eat more food while keeping your calorie intake low.
Consider the difference between eating grapes and raisins regarding energy density and total food volume.
One cup of fresh grapes has 104 calories, while one cup of raisins (dried grapes) has 493 calories.2FoodData Central. (n.d.). Fdc.nal.usda.gov. https://fdc.nal.usda.gov/fdc-app.html#/food-details/1102665/nutrients
This is almost five times as many calories for the same volume of food in the same actual food product. Here, you can eat the same volume of grapes for 389 fewer calories!
The Volumetrics diet categorizes all foods into one of four groups based on their energy density and nutrient density.
These groupings are arranged from least calorically dense in Group 1 to most energy dense in Group 4.
According to the International Food Information Council, the groupings of foods break down as follows:3International Food Information Council. (n.d.). International Food Information Council. https://ific.org/
- Group 1: Foods that are least calorically dense, such as low-sugar fresh fruits (berries, citrus, melon, grapes, etc.), non-starchy vegetables, broth-based soups and stocks, and nonfat milk.
- Group 2: Foods that are low in energy density, such as starchy vegetables (potatoes, corn, peas, sweet potatoes, etc.), grains, sugary fruits (pineapples, mangos, bananas, cherries, etc.), lean proteins, legumes (peas, lentils, beans), whole grains, low-sugar breakfast cereals, and low-fat mixed dishes.
- Group 3: Foods with a relatively high caloric density, such as meat, cheese, bread, pasta, pretzels, granola bars, ice cream, pizza, bagels, etc.
- Group 4: These are the highest energy-dense foods. They tend to be high in refined carbohydrates, sugar, and/or fat, such as butter, nuts, peanut butter, oils, crackers, cookies, chocolate, candy, and chips.
Group 1 foods are considered free foods.
If you are familiar with the Weight Watchers diet program (now called the WW diet), these free foods are essentially foods that you can eat without limitations, and they dont count towards your total daily food allowance.
You can eat group one foods without restriction because these are nutrient-dense foods but not energy-dense foods.4National Cancer Institute. (2011). NCI Dictionary of Cancer Terms. National Cancer Institute; Cancer.gov. https://www.cancer.gov/publications/dictionaries/cancer-terms/def/nutrient-dense-food
This means that they provide an abundance of nutrients per calorie and very few calories per gram or net weight of the food item.
Then, as you work your way up from Groups 2 to 4, you are supposed to be increasingly mindful of not only your portion sizes but also the frequency at which you are eating these high energy density foods.
Specific guidelines pertain to everyone regarding how much of each food group you can have on the Volumetrics diet.
It is recommended that you have three meals and two snacks per day.
Also central to the Volumetrics diet for weight loss is physical activity and the recommendation to exercise at least 30 minutes every day.
What Are the Health Benefits of the Volumetrics Diet?
Research suggests that the volumetrics diet has benefits based on various associations between the energy density of foods and aspects of health.
Here are some Volumetrics diet plan benefits:
- Supporting weight loss: Eating more low-energy-density foods may help control appetite,5Buckland, N. J., Camidge, D., Croden, F., Lavin, J. H., Stubbs, R. J., Hetherington, M. M., Blundell, J. E., & Finlayson, G. (2018). A Low EnergyDense Diet in the Context of a Weight-Management Program Affects Appetite Control in Overweight and Obese Women. The Journal of Nutrition, 148(5), 798806. https://doi.org/10.1093/jn/nxy041 support weight loss,6Vadiveloo, M., Parker, H., & Raynor, H. (2017). Increasing low-energy-dense foods and decreasing high-energy-dense foods differently influence weight loss trial outcomes. International Journal of Obesity, 42(3), 479486. https://doi.org/10.1038/ijo.2017.303 prevent weight gain,7Stelmach-Mardas, M., Rodacki, T., Dobrowolska-Iwanek, J., Brzozowska, A., Walkowiak, J., Wojtanowska-Krosniak, A., Zagrodzki, P., Bechthold, A., Mardas, M., & Boeing, H. (2016). Link between Food Energy Density and Body Weight Changes in Obese Adults. Nutrients, 8(4), 229. https://doi.org/10.3390/nu8040229 and reduce the risk of obesity.8Rouhani, M. H., Haghighatdoost, F., Surkan, P. J., & Azadbakht, L. (2016). Associations between dietary energy density and obesity: A systematic review and meta-analysis of observational studies. Nutrition, 32(10), 10371047. https://doi.org/10.1016/j.nut.2016.03.017
- Reducing the risk of cardiovascular disease: There is some research to suggest that following a Volumetrics diet plan centering around low energy-dense foods may potentially reduce the risk of cardiovascular disease by improving numerous risk factors, such as decreasing total cholesterol, LDL cholesterol, and fasting blood glucose levels. Following a low-energy-density diet was also found to help prevent weight regain in participants who had lost weight more than a standard calorie restriction diet.9Azadbakht, L., Karimi, G., Haghighatdoost, F., & Esmaillzadeh, A. (2016). Low energy density diet, weight loss maintenance, and risk of cardiovascular disease following a recent weight reduction program: A randomized control trial. Journal of Research in Medical Sciences, 21(1), 32. https://doi.org/10.4103/1735-1995.181992
- Reducing the risk of Type 2 diabetes: A large observational study with 143,204 women found that those whose diet was highest in terms of the average energy density of the foods had a 24% greater risk of developing type 2 diabetes than women who followed a lower-energy-dense diet.10Hingle, M. D., Wertheim, B. C., Neuhouser, M. L., Tinker, L. F., Howard, B. V., Johnson, K., Liu, S., Phillips, L. S., Qi, L., Sarto, G., Turner, T., Waring, M. E., & Thomson, C. A. (2017). Association between Dietary Energy Density and Incident Type 2 Diabetes in the Womens Health Initiative. Journal of the Academy of Nutrition and Dietetics, 117(5), 778-785.e1. https://doi.org/10.1016/j.jand.2016.11.010
- Encourages healthy eating: The foods that are prioritized on the Volumetrics diet are those that are truly the healthiest and nutrient-dense but not calorie-dense, and they are free from added sugars, refined grains, and any sort of processing. The foods in Group 1 are also high-fiber, which have many benefits, such as supporting digestion, increasing satiety, and nourishing the healthy gut bacteria.
- Promotes regular exercise, which is great for weight management and health.11Clark, J. E. (2015). Diet, exercise or diet with exercise: comparing the effectiveness of treatment options for weight-loss and changes in fitness for adults (1865 years old) who are overfat, or obese; systematic review and meta-analysis. Journal of Diabetes & Metabolic Disorders, 14(1). https://doi.org/10.1186/s40200-015-0154-1
- Not overly restrictive: Lastly, another Volumetrics diet benefit is that there are no foods that are technically off-limits or banned. Studies suggest that imposing restrictions on what we eat can cause cravings or can lead to abandoning a diet in the long term. Plus, Group 1 foods are free foods, which gives dieters the freedom to feel like there is always something they can eat that wont derail their weight loss.
Overall, the Volumetrics diet is one of the best diets for weight loss and health for those who enjoy eating or want to feel full without the necessary need for calorie counting.
However, the Volumetrics diet plan isnt necessarily right for everyone.
The lack of structure and rules can make it difficult to lose weight if you arent making smart choices or really going gung-ho on portion sizes, even in the lower food groups.
Additionally, if you suffer from a binge eating disorder or tend to overeat, the Volumetrics diet might be triggering. The best option would be to work with a registered dietitian to see what would be the healthiest diet choice and eating habits for you.
If you are still shopping around for the perfect diet for you, you can check out our guide to the Mediterranean Diet:
