Volume Eating: Big Plates on Fewer Calories

The short version

• Calorie density is how many calories a food has for its weight, and it strongly shapes how much you eat.
• Foods with lots of water and fiber let you eat bigger portions on fewer calories.
• You still need some protein and fat to stay satisfied and get enough nutrients.

In a sentence

Eat large portions of foods that are low in calories for their size.

How restrictive

Counting needed?

Optional

Quality of evidence

Moderate

Typical cost

Low

Main drawback

Can fall short on protein and fat if you overdo the vegetables

See how this compares with every other diet →

The idea

Your stomach notices the amount of food you eat more than the calories in it. Foods with lots of water and fiber take up space, so you feel fuller on fewer calories. This approach is also known as Volumetrics, after a popular book by nutrition researcher Barbara Rolls.

Here are roughly the same 100 calories in different foods:

Foods to lean on

• Low density (eat plenty): Non-starchy vegetables, most fruit, broth-based soups, salad with light dressing
• Medium density (reasonable portions): Lean protein, beans, whole grains, potatoes, low-fat dairy
• High density (small portions): Cheese, nuts, oils, fried foods, crackers, chips, sweets

Don't cut out the high-density group. Nuts and olive oil are healthy. They just need measuring.

Easy swaps

• Start lunch or dinner with soup or a big salad.
• Double the vegetables in your pasta and use less pasta.
• Add zucchini or cauliflower rice to your regular rice, half and half.
• Add mushrooms or lentils to ground meat in tacos and sauces.
• Have fruit with yogurt instead of granola.
• Make an omelet with one extra egg white and a big pile of spinach and peppers.
• Choose popcorn over chips.

What the evidence says

Trials from Barbara Rolls's lab and others have found that people tend to eat a fairly consistent weight of food, so lower calorie density leads to fewer calories without more hunger. Longer studies suggest it can help with weight loss and keep portions satisfying, and it's consistent with the NIH trial showing that people ate more when offered ultra-processed, calorie-dense food. As with any approach, it depends on you continuing to do it.

Keep it balanced

• Include protein every time. Vegetables alone won't hold you for long.
• Keep some fat. You need it for vitamin absorption and satisfaction. Salad without any dressing or fat is a sad way to live.
• Avoid only low-calorie snacks. Eating 4 cups of cucumbers is fine, but it isn't a meal.
• Increase fiber slowly. Too much too fast can cause gas and bloating. See fiber.

Sources

1. Rolls, Nutrition Bulletin (2017): Dietary energy density, applying behavioural science to weight management
2. NHLBI: Aim for a Healthy Weight
3. Harvard T.H. Chan School of Public Health: Fiber
4. Hall et al., Cell Metabolism (2019): Ultra-processed diets cause excess calorie intake

This guide is general information, not medical advice. Please check with a clinician before making big changes, especially if you have a health condition, take medication, or are pregnant. Read the full disclaimer.