What Is the Volumetrics Diet?

Volumetrics is not a new diet, but it has stood the test of time. Many people use it to lose weight and keep the pounds off for good. The diet is based on the premise that it’s the volume of food eaten, rather than the number of calories consumed, which leads to weight loss. When we eat more food, we experience a sense of satiety or fullness.

Barbara Rolls, Ph.D., is a nutrition and obesity researcher at Penn State University. She developed the Volumetrics diet based on her research and coauthored The Ultimate Volumetrics Diet, published in 1999. Her second book, The Volumetrics Eating Plan, was first published in 2005 and showcases tips, techniques, and recipes.

What Can You Eat?

On the Volumetrics diet, you eat low-calorie foods that fill you up, which helps you lose weight without feeling like you’re on a diet. The plan is designed so that you don't feel hungry or deprived.

You will also learn about "calorie density" on this plan. Foods recommended on the Volumetrics diet have a low energy density, so they are more filling for fewer calories. Foods that you should limit on the Volumetrics diet are energy-dense, meaning even if they have a lot of calories, you need to eat more of them to feel full. 

What You Need to Know

To follow the plan, you will eat low-calorie, high-volume foods that contain either a lot of water or a lot of diet-friendly fiber. Water and fiber both increase the sense of satisfaction or satiety. No food is completely banned on the Volumetrics eating plan. You can enjoy foods that are considered to be calorie-dense, like chocolate, as long as it's a treat and as long as you stay within your daily caloric recommendations.

The recommended lifestyle changes that lead to long-term weight management include keeping an exercise and food journal and planning ahead for social situations that may throw you a curveball, such as parties. They also recommend that you get at least 30 minutes of exercise on most days of the week. In addition, they suggest you weigh in no more than once a week during the weight-loss phase.

The Volumetrics diet divides foods into four categories, based on their calorie density:

Category One

These foods are very low-density, and the diet emphasizes eating a lot of them. Category one foods include fruits and vegetables (except starchy ones), nonfat milk, and broth-based soup.

Category Two

You will eat lots of foods from category two as well, in reasonable portions. These low-density foods include grains, legumes, low-fat meats, and starchy fruits and vegetables.

Category Three

This category's medium-density foods are permitted on the Volumetrics plan, but take care to eat them in moderation (small servings). These are foods that are higher in fat, refined carbohydrates, and/or sugar: Meat, cheese, French fries, bread, ice cream, and so on.

Category Four

High-density category four foods are eaten only occasionally. They are even higher in fats, carbs, and sugars than the category three foods. These include butter, nuts, oil, crackers, cookies, and candy.

Frequent eating is recommended on the Volumetrics diet—three meals and a snack or two, as long as they are following the Volumetrics principles (heavy on category one and two foods).

The Volumetrics books help you learn the calorie density of the foods you want to eat, so you can adjust the amounts accordingly. They provide a food density list for hundreds of foods, plus a technique for figuring out the calorie density of any food using the number of calories and serving size.

The books include a formula for you to determine how many calories to eat each day, meal plans for 1,600 and 2,000 daily calories, and lots of healthy recipes as well.

The book also provides a maintenance plan to follow once you have met your goal weight, or after six months have passed. After you’ve maintained your weight for another six months, you can start the weight-loss plan over again.

Sample Shopping List

The Volumetrics Diet focuses on high volume, lower-calorie foods, with some higher calorie whole foods allowed in smaller quantities. As such, you will be shopping for a large amount of produce. Keep in mind that nothing is truly off-limits with the Volumetrics Diet, so shopping at a large grocery store with a wide variety of foods and fresh produce is best. Since the Volumetrics Diet is flexible in terms of food choices, this is not a definitive shopping list and if following the diet, you may find other foods that work best for you.

• Fresh fruits and vegetables with high water content (apples, tomatoes, cucumber, grapefruit, zucchini)
• Frozen fruits or vegetables (berries, cherries, peas, green beans)
• Whole grains (steel cut oats, brown rice)
• Beans and legumes (black beans, kidney beans, black-eyed peas)
• Low-fat fish (tilapia, cod, sole)
• Lean skinless protein (chicken breast, turkey breast)

Sample Meal Plan

You can eat three meals plus snacks on the Volumetrics Diet. There are different meal plans for the varying calorie levels, which you can determine using the book's formula. You can modify each meal plan to your specific caloric needs. The 1,600-calorie plan, for example, allows for a 400-calorie breakfast, a 500-calorie lunch, a 500-calorie dinner, and a 200-calorie snack. But you can make adjustments. You can also use guidelines in the book to plan your own meals.

Day 1

• Breakfast: Oatmeal with berries, almond milk, and some pumpkin seeds
• Lunch: Garden salad topped with grilled tilapia topped with a squeeze of lemon and drizzle of olive oil
• Dinner: Baked skinless, boneless chicken breast; boiled potatoes; sauteed spinach
• Snack: Low fat cottage cheese with apples and cinnamon

Day 2

• Breakfast: Boiled eggs; steamed asparagus; 1 piece of whole-grain toast
• Lunch: Homemade soup with chickpeas and vegetables; side garden salad
• Dinner: Chicken breast, mushrooms, bell peppers in marinara sauce with black bean noodles
• Snack: Low-fat Greek yogurt with berries

Day 3

• Breakfast: 1 egg plus 3 egg whites scrambled; 1 small whole wheat tortilla; baby spinach; 1/2 ounce of low-fat cheese
• Lunch: Tuna mixed with avocado, cucumber, lettuce on a whole-wheat tortilla
• Dinner: Lean grilled steak; rice pilaf; grilled mushrooms, peppers, and onions
• Snack: Chickpea hummus with carrots, grape tomatoes, and whole-grain pita bread

Pros and Cons

Pros

Nutrition

The Volumetrics plan does not exclude any foods or food groups, but it does emphasize those foods that offer nutrients and fiber without a lot of calories. So it is sensible and will allow you to get all the nutrients you need from food.

Efficacy

Research by Rolls and others shows that eating this way can help people lose weight.

Lifestyle Changes

The plan encourages regular, moderate physical activity, which is a definite plus. Many diets ignore exercise altogether, despite the fact that regular activity is a vital part of a lifestyle that leads to long-term health and permanent weight loss. Additional recommendations, such as keeping a food diary, will also help users adjust to a new lifestyle.

The Volumetrics diet has a lot going for it, but no one way of eating is perfect for everyone.

Cons

Time Consuming

Especially when you are new to Volumetrics, it will take time. You will need to analyze your food choices for density, keep track of what you are eating, count calories, and prepare food.

Lack of Online Support

There are a few Volumetrics apps, but none developed by the book's authors. If you want to rely on an app instead of a book to check a food's density and track your meals, you will not be able to do so easily.

Is the Volumetrics Diet a Healthy Choice for You?

The Volumetrics diet is inclusive and balanced, like other diets that encourage lifestyle change and gradual weight loss. It's not a quick fix but a way of eating that takes some time to learn and adopt.

The food recommendations in the Volumetrics diet are consistent with the eating guidelines promoted by the USDA. The eating plan promotes a healthy, balanced diet of fruits, vegetables, and whole grains and encourages you to limit your saturated fat intake. 

The daily calorie intakes suggested for weight loss on the Volumetrics plan (1,600 for women, 2,000 for men) are fairly sustainable for most people, but the USDA determines your needs should be determined by your activity level, sex, and age. While the book helps you determine a smart calorie range for you, you can also do so using this calculator.

Health Benefits

Large Variety

All foods are included in this diet. It's the amount of them that matters. You have the freedom to eat as much of the lowest-density foods as you like. And you can still eat the highest-density foods, but do so sparingly. The foods you will focus on the most are highly nutritious, making it easier to obtain the recommended amount of vitamins, minerals, fiber, and macronutrients.

Safe and Sustainable

This diet is very safe and is typically sustainable as long as it's followed carefully. It is a gradual change, not a fast way to drop 10 pounds. This is a lifelong way of eating. Once users have lost the desired amount of weight, they switch to a maintenance plan that helps them keep their weight steady.

Effective

Focusing on high-volume foods lessens the chances that you will feel hungry. Since you can eat anything on the Volumetrics Diet, including calorie-dense foods in small portions, you are unlikely to quit the diet due to feeling deprived. Research has found that eating low-calorie dense foods is a highly effective weight loss strategy.

A Word From Verywell

When the caloric guidelines and food recommendations set forth in this plan are followed correctly, this diet is both effective and nutritious. It will not bring major results very quickly but instead leads to a safe, gradual weight loss of about one to two pounds a week. That's ideal for long-term success—and you can continue eating this way for the long term, too.