Healthline diet score: 3.0 out of 5
The Volumetrics Diet is an eating plan designed to promote weight loss by having you fill up on low calorie, nutrient-dense foods.
It’s meant to reduce feelings of hunger by prioritizing foods with a high water content and low calorie density. It also encourages other healthy habits, such as regular exercise and keeping a food journal.
Still, you may wonder whether it’s a good fit for you.
This article provides a comprehensive review of the Volumetrics Diet, including its effectiveness for weight loss.
diet review scorecard
- Overall score: 3.0
- Weight loss: 2.5
- Healthy eating: 3.5
- Sustainability: 3.5
- Whole body health: 3.5
- Nutrition quality: 2.0
- Evidence-based: 3.0
BOTTOM LINE: The Volumetrics Diet emphasizes foods with a low calorie density, which can increase weight loss and improve overall diet quality. However, it restricts some healthy food groups and is time-intensive.
What is the Volumetrics Diet?
The Volumetrics Diet claims to help you feel full while eating fewer calories.
It’s based on a book by nutrition scientist Dr. Barbara Rolls, which provides in-depth guidelines, recipes, and information on how to calculate the calorie density of your favorite foods.
The diet encourages you to eat nutrient-dense foods that are low in calories and high in water, such as fruits, vegetables, and soups. Meanwhile, it limits calorie-dense foods like cookies, candies, nuts, seeds, and oils.
Dr. Rolls asserts that these restrictions help you feel fuller for longer, cut your calorie intake, and promote weight loss.
Unlike other diets, the Volumetrics Diet is intended to foster healthy eating habits and should be viewed as a long-term lifestyle change rather than a short-term solution.
The Volumetrics Diet prioritizes low calorie, nutrient-dense foods with a high water content, which is thought to help keep you feeling full to encourage weight loss.
How it works
The Volumetrics Diet groups foods into four categories based on their calorie density:
- Category 1 (very low calorie density): calorie density of less than 0.6
- Category 2 (low calorie density): calorie density of 0.6–1.5
- Category 3 (medium calorie density): calorie density of 1.6–3.9
- Category 4 (high calorie density): calorie density of 4.0–9.0
Dr. Rolls’s book provides detailed information on how to calculate calorie density. In general, you should divide the number of calories in a particular serving size by its weight in grams. You’ll end up with a figure between 0 and 9.
Foods with a high water content, such as broccoli, typically score very low in calorie density, while desserts and processed foods like dark chocolate usually rank high.
A typical meal on the Volumetrics Diet should mostly comprise foods from Category 1, as well as include foods from Category 2 to help round out your plate. You can eat small amounts of foods from Category 3 and very limited portions from Category 4.
The diet’s standard meal plan provides around 1,400 calories per day but can be adjusted to fit your calorie goals by adding extra snacks or increasing portion sizes.
No foods are completely off-limits on the Volumetrics Diet. In fact, you can include foods with a high calorie density by modifying your portion sizes and adjusting your other meals.
Furthermore, the diet encourages at least 30–60 minutes of exercise each day.
You should keep track of your physical activity and food intake in a journal to monitor your progress and identify areas that may need improvement.
The Volumetrics Diet categorizes foods based on their calorie density, prioritizing those that score very low. It also encourages you to get regular exercise, as well as log your food intake and physical activity.
Does it work for weight loss?
Although few studies have examined the Volumetrics Diet specifically, research suggests that its central tenets aid weight loss.
Promotes low calorie intake
Selecting foods with a low calorie density is particularly effective. Because these foods have a substantial volume but are low in calories, you can eat large servings without significantly increasing your calorie intake (1).
Notably, a review of 13 studies in 3,628 people tied foods with a lower calorie density to increased weight loss. Similarly, an 8-year study in over 50,000 women associated high-calorie-density foods with increased weight gain (2, 3).
Choosing foods with a low calorie density may also help curb cravings and reduce appetite, which could boost weight loss.
In an older study in 39 women, participants ate 56% more calories when served a large portion of a high-calorie-density meal, compared with a smaller, low-calorie-density meal (5).
Encourages regular exercise
Exercise is another important component of the Volumetrics Diet.
The diet recommends getting at least 30–60 minutes of physical activity per day, which may increase weight loss and fat loss by raising your energy expenditure, or the number of calories burned during the day (6, 7).
The Volumetrics Diet encourages regular exercise and emphasizes foods with a low calorie density, which are effective strategies to increase weight loss and reduce hunger and cravings.
Other health benefits
The Volumetrics Diet may offer several other health benefits.
May boost diet quality
By encouraging healthy foods that are low in calories but high in fiber, vitamins, and minerals, the Volumetrics Diet may help increase your intake of key nutrients and protect against nutritional deficiencies.
Limits processed foods
Although the Volumetrics Diet doesn’t completely ban any foods, most processed foods have a high calorie density and should be restricted as part of the plan.
Processed foods are not only typically lacking in essential nutrients like fiber, protein, vitamins, and minerals but also usually higher in calories, fat, sugar, and sodium.
Flexible and sustainable
Unlike most fad diets, the Volumetrics Diet should be viewed as a long-term lifestyle change.
It pushes you to become more aware of your eating habits and food choices, which can help you make healthier dietary decisions by prioritizing foods with a lower calorie density, such as fruits and vegetables.
Additionally, because no foods are banned on the diet, you can enjoy your favorite dishes by making modifications and adjustments to your diet.
This may make the Volumetrics Diet a good fit for people seeking some flexibility and a sustainable eating plan to follow long term.
The Volumetrics Diet limits processed foods and may improve diet quality. It’s also flexible and designed to be maintained long term.
The Volumetrics Diet has a few drawbacks to be aware of.
Time-intensive with few online resources
The diet requires significant time and energy investments, which may make it untenable for some people.
In addition to finding recipes, planning meals, and calculating calorie density, you’re supposed to prepare most of your meals and snacks at home. This may make the diet too restrictive for those with a busy lifestyle, cramped kitchen, or limited access to fresh produce.
Although some support groups and recipes are available, online apps and resources for the diet are somewhat limited.
In fact, you may need to purchase the book by Dr. Rolls to calculate your meals’ calorie density and track your food intake effectively.
Limits healthy fats
The diet also restricts certain foods rich in healthy fats, including nuts, seeds, and oils.
Moreover, many nutritious eating patterns like the Mediterranean diet encourage you to eat these foods.
Places too much emphasis on calories
Given that the Volumetrics Diet is based on calorie density, high calorie foods are limited.
This means that nutritious, high calorie foods like avocados, nut butter, and whole eggs are limited, while processed, low calorie foods like fat-free salad dressing and diet ice cream are allowed due to their low calorie density.
Low calorie foods are often packed with added sugar and other unhealthy ingredients to enhance their taste. Just because something is low in calories doesn’t mean it’s healthy.
The Volumetrics Diet is time-intensive, and online resources are somewhat limited. It also restricts foods high in healthy fats, including nuts, seeds, and oils.
Foods to eat and avoid
Rather than banning any foods entirely, the Volumetrics Diet divides them into four categories based on their calorie density.
Foods in Category 1 have a very low calorie density and should comprise the majority of your diet. They include:
- Fruits: apples, oranges, pears, peaches, bananas, berries, and grapefruit
- Non-starchy vegetables: broccoli, cauliflower, carrots, tomatoes, zucchini, and kale
- Soups: broth-based soups like vegetable soup, chicken soup, minestrone, and lentil soup
- Nonfat dairy: skim milk and nonfat yogurt
- Beverages: water, black coffee, and unsweetened tea
Foods in the second category have a low energy density and can be enjoyed in moderation. They include:
- Whole grains: quinoa, couscous, farro, buckwheat, barley, and brown rice
- Legumes: chickpeas, lentils, black beans, and kidney beans
- Starchy vegetables: potatoes, corn, peas, squash, and parsnips
- Lean proteins: skinless poultry, white fish, and lean cuts of beef or pork
Foods in the third category are considered medium calorie density. While they’re permitted, it’s important to keep an eye on serving sizes. These foods include:
- Meat: fatty fish, poultry with the skin, and high fat cuts of pork and beef
- Refined carbs: white bread, white rice, crackers, and white pasta
- Full fat dairy: whole milk, full fat yogurt, ice cream, and cheese
Foods in the final category are classified as high energy density. These foods contain lots of calories per serving and should be eaten sparingly. They include:
- Nuts: almonds, walnuts, macadamia nuts, pecans, and pistachios
- Seeds: chia seeds, sesame seeds, hemp seeds, and flax seeds
- Oils: butter, vegetable oil, olive oil, margarine, and lard
- Processed foods: cookies, candies, chips, pretzels, and fast food
Foods with a very low calorie density include non-starchy veggies, broth-based soups, and fruits. These should comprise the bulk of your diet. Meanwhile, you should limit your intake of processed foods, nuts, seeds, and oils.
On the Volumetrics Diet, you should eat 3 meals per day, plus 2–3 snacks. Here’s a 3-day sample menu:
- Breakfast: oatmeal with fruit and a glass of skim milk
- Snack: carrots with hummus
- Lunch: grilled chicken with quinoa and asparagus
- Snack: sliced apples and light string cheese
- Dinner: baked cod with spiced vegetable couscous
- Breakfast: nonfat yogurt with strawberries and blueberries
- Snack: a hard-boiled egg with tomato slices
- Lunch: turkey chili with kidney beans and vegetables
- Snack: a fruit salad with melon, kiwi, and strawberries
- Dinner: zucchini boats stuffed with ground beef, tomatoes, bell peppers, and marinara sauce
- Breakfast: scrambled eggs with mushrooms, tomatoes, and onions, plus a slice of whole wheat toast
- Snack: a smoothie with skim milk, banana, and berries
- Lunch: chicken noodle soup with a side salad
- Snack: air-popped popcorn
- Dinner: whole grain pasta with turkey meatballs and sautéed vegetables
The meal plan above provides some simple meal and snack ideas for the Volumetrics Diet.
The bottom line
The Volumetrics Diet prioritizes foods with a low calorie density and high volume. It promotes weight loss by enhancing feelings of fullness while reducing hunger and cravings.
It may also improve your diet quality by increasing your intake of nutrient-dense foods like fruits and vegetables.
However, the Volumetrics Diet also requires substantial time and energy, restricts several healthy foods, and offers limited online resources, which may make it unsuitable for some people.