How can a whole foods plant-based diet help you achieve a healthy weight, and maintain it long-term? It comes down to the simple principle of calorie density, and this guide will help you understand it!
When switching from a ‘standard’ diet to one based entirely on whole plant foods, many people are surprised to see the number on the scale gradually drop, despite the fact that they are eating large volumes of filling food. It is well established that weight loss and long-term weight management are benefits commonly associated with whole foods plant-based eating. And while many understand this to be a product of eating less fat, less salt, less junk, and more fiber, few are aware that there is a simple underlying principle that explains it all: calorie density.
What is calorie density, exactly? Calorie density is the concentration of calories found in equal weights of food. To put it simply, if you eat 100 grams of lettuce, you consume fewer calories than if you eat 100 grams of Oreos. While comparisons like this one are quite obvious, there are others that are more subtle. To illustrate the effect of calorie density in our day-to-day lives, let’s look at two examples.
Say your normal daily intake of food looks like this:
Breakfast: Cinnamon raisin bagel with 2 tbsp. cream cheese (375 calories)
Lunch: Mixed salad with 4 oz. grilled skinless chicken + 1 tbsp. parmesan cheese + 3 tbsp. oil-based vinaigrette (480 calories)
Dinner: 1.5 cups cooked white pasta with 2/3 cup beef bolognaise + a mixed green salad with 2 tbsp. oil-based vinaigrette (700 calories)
Snacks: 1 apple + 1 granola bar (235 calories)
TOTAL = 1790 CALORIES
You decide that you want to adopt a whole foods plant-based diet, and you change your meals accordingly. Your day now looks like this:
Breakfast: 1 cup cooked oatmeal with 1 diced apple & 1 tsp. cinnamon & sugar (300 calories)
Lunch: Mixed salad with 4 oz. chickpeas, 2 tbsp. lemon juice + 1 medium baked potato (420 calories)
Dinner: 1.5 cups cooked brown rice with ⅔ cup bean & vegetable chili + a mixed green salad with 2 tbsp. lemon juice (600 calories)
Snacks: 1 apple + 1 baked sweet potato (185 calories)
TOTAL = 1505 CALORIES
So what's happened? You've significantly decreased your daily caloric intake, even though you’re actually consuming a greater volume of food. The result? You feel fuller and more satisfied despite having eaten fewer calories. Better yet, it required no conscious effort on your part to limit calories or control portion sizes (in fact, none of the whole foods plant-based experts recommend counting calories or measuring portions- at all.) This principle is what makes a low energy density diet so easy to follow long term. Calorie-counting and portion control feel restrictive, and often do nothing to satisfy your body's basic hunger drives. This can lead to cycles of bingeing and restricting, which is neither beneficial for your overall health or for long-term weight loss success. Eating a diet that is healthful and abundant, but naturally low in calorie density will allow you the freedom to eat until satisfied, knowing that these foods help your body to accurately gage when it is full.
To further demonstrate this principle, here are the average amounts of calories (per pound) found in common foods & food groups:
Calories per pound
In-tact whole grains & starchy vegetables
(brown rice, quinoa, barley, millet, buckwheat, potatoes, yams, sweet potatoes, etc.)
Legumes (beans, peas, lentils)
|Animal foods (meat, fish, eggs, etc.)
Flour-based whole grain products
(Whole wheat pasta, whole wheat bread)
|Refined flour-based products
|Nuts and Seeds
As you can see, vegetables have the lowest calorie density- an average of 100 calories per pound. These are ideal for adding bulk to your meals, as well as providing ample amounts of vitamins and minerals. However, it’s important to remember that you cannot rely solely on very low energy density foods like fruits and vegetables, as they are unlikely to provide sufficient calories to meet your daily needs.
The bulk of calories in a whole foods plant-based diet should be coming from whole grains, legumes, and starchy vegetables. These foods contain plenty of fiber, minerals and protein, making them both filling and nutritious. (You may consume the same volume of non-starchy vegetables each day, but they will not contribute greatly to your overall caloric intake.) As you can see, whole grains and legumes clock in at 500-600 calories per pound. Compare this to a diet where the ‘mainstays’ are animal products (meat, fish, eggs) and flour-based starches (bread, pasta) which together have an average of 1200 calories per pound. What sort of difference does this make? A difference of 400-700 calories per pound of food. Considering we eat an average of 3-5 pounds of food each day, this can have a tremendous impact when it comes to achieving a healthy weight.
You’ll also notice that oils top the table at 4000 calories per pound. Just one tablespoon of oil contains 120 calories, but only a fraction of the nutrients found in the whole food that it's extracted from. Because a whole foods plant-based diet excludes all free oils (including olive and coconut oils) you can easily and reduce your caloric intake by a significant amount every single day, without even noticing.
(For more information on why oils are not included in the diet, please refer to this article.)
Finally, it’s important to note that even within the confines of a healthy plant-based diet, some foods are clearly better for weight loss and maintenance than others. Those looking to achieve weight loss generally do better when they limit higher density foods like nuts, seeds, avocados, and flour-based products like breads, crackers, dry cereals and pastas. Basing all your meals on intact whole grains, legumes, fruits, starchy vegetables, and an increased volume of non-starchy vegetables has proven to be most effective. Those who maintain a healthy weight or lean figure can generally include small amounts of higher-density plant foods like nuts, seeds, and whole grain flour products, without worry.
Remember, this is not a miracle diet, a fad diet, or a diet designed for rapid weight loss. It’s a healthy eating plan you can adopt for life that will benefit your body, both inside and out. Looking good is just a bonus!
To understand more about calorie density, you can watch this short presentation by Jeff Novick, MS RD.