Blog #49 Andrew Siegel, M.D
Bottom line: Eating too much high caloric-density food has contributed to the obesity epidemic. A diet consisting of low-caloric density foods will allow us to eat more food, but with fewer intake of calories. This will keep us satisfied and limit the intake of excessive calories, promoting the maintenance of a healthy weight and general well being.
Density is defined as mass per unit volume. For example, New Jersey is the densest state in the nation in terms of population, with the highest number of people per square mile. All foods have a property called caloric density (energy density), which is defined as food calories divided by food weight. Weight can be used as a substitute for volume since it is easier and more precise to weigh a food item than measure its volume.
A major factor in high caloric vs. low caloric density is water content. Water serves to increase the volume of a food without adding any calories. Another factor is fat content since fat packs a whopping 9 calories/gram as opposed to carbohydrates and proteins that are 4 calories/gram. Thus, the less fat and more water content a food has, the lower its caloric density and the less amount of calories per unit weight it provides. For example, a given weight of vegetables has a lower caloric density than the same given weight of pizza. Most fruits and vegetables have a very low calorie per weight measure. On the other hand, many meats are high in caloric density.
One reason that we get fat is because we consume too many foods that have a high caloric density. One goal of a healthy eating plan is to eat foods that have a relatively low ratio of calories to weight–this will serve to keep our calorie count under control, yet the weight of the food consumed will keep us satisfied, if not full. Dropping a few pounds simply becomes a matter of avoiding or minimizing high caloric density foods and replacing them with foods with low caloric density. Additionally, combining low caloric density foods with high caloric density foods can lower the overall caloric density of a meal, making it healthier. A classic example is raisins as opposed to grapes. Twenty grapes have the same amount of calories as twenty raisins, but much more volume and weight. It would be easy to hold twenty raisins in your palm and pop them into your mouth; doing the same with the identical number of grapes would be virtually impossible. The difference is the presence of the increased water content of the grapes as opposed to the minimal water content of the dried fruit. The water content of the grapes makes them occupy a much greater volume in your hand as well as in your stomach, which makes them much more satisfying than raisins in terms of quelling hunger as well as thirst. It is difficult to get full on raisins since they are so dense, but easy to do so on grapes because they have so much volume. It is therefore very easy to consume excessive calories munching on a box of raisins, but much more difficult to do so with a bowl full of grapes. The greater volume lends itself to not only feeling satisfied, but also to built-in portion control.
As another example, let us compare fruit juices to whole fruit. It is very easy to drink 12 ounces of orange juice, what in essence amounts to about 170 calories of less-than-healthy fiber-free sugar. To get that kind of caloric load from nature’s whole product—the orange—you would have to eat almost 3 of them. I can’t begin to imagine eating three oranges—the bulk and weight from the fiber is just too filling, plus the work involved in peeling the orange would certainly be a deterrent. Additionally, the orange is a discrete unit that naturally lends itself to a defined volume of consumption, while there is absolutely no such clear-cut unit with the juiced by-product.
Most people eat a more-or-less consistent volume (weight) of food on a daily basis. So, by choosing foods of less caloric density, one will feel fuller on a diet of fewer calories. That is the principle behind a low-density, high-volume diet. This is essentially the same concept behind drinking a glass or two of water before every meal. This will not only quench thirst that can be confused with hunger, but can serve to stimulate the receptors in the stomach that trigger fullness. A low caloric-dense diet achieves the same endpoint by having the water content within the food itself. Water adds weight and volume to foods, but adds no calories.
The same applies to air—it adds volume without calories. When you froth up a smoothie in the blender, air is folded into the concoction, which increases volume without changing the weight or calories, and this extra volume will stimulate the fullness receptors in the stomach.
Calorie density counts of selected foods (Adapted from The Ultimate Volumetrics Diet by Barbara Rolls)
Food / Calorie density
Salad greens 0.2
Lentil soup 0.6
Cooked peas 0.8
Baked potato 0.9
Cooked whole wheat pasta 1.2
Lean broiled ground beef 2.2
Ice cream 2.8
French fries 2.9
Hard pretzels 3.5
Trail mix 4.3
Cooked bacon 5.2
Dark chocolate 5.7
Peanut butter 6.3
Olive oil 8.8
- Beware of caloric-dense foods like dried fruit as it is much easier to overdo caloric consumption: raisins vs. grapes, prunes vs. plums, dried figs vs. whole figs, etc.
- Start meals with soup, salad or cut up fresh fruit—this low-density caloric consumption will fill you up and minimize the chances of over-eating caloric dense entrees
- Drink low caloric density beverages including water, seltzer or herbal teas instead of high caloric density, liquid calories from sodas, sweetened beverages or juices
- Dilute juices with seltzer to decrease their calorie density
- Drink light beer instead of full beers
- Dilute thick soups with water to decrease the caloric density
- Add chopped vegetables to pizza, pasta, casseroles, stews, meat loaf, macaroni and cheese and soups
- Add pureed vegetables to sauces and toppings
- Add extra carrots to carrot cake, extra zucchini to zucchini bread, etc.
- Instead of ice cream as a dessert, have an assortment of fruits and add a small scoop of ice cream as a topping
- Use less caloric-dense toppings on potatoes such as Greek yogurt as an alternative to sour cream
- Use less caloric-dense bases for dips such as Greek yogurt instead of sour cream
- Use less caloric-dense bases for salad dressings such as Greek yogurt instead of mayonnaise
- Eat less caloric-dense snacks such as baked chips instead of fried chips
- An apple is much less calorie dense than a piece of apple pie
- Enjoy natural caloric-dense foods as an alternative to processed caloric-dense foods, e.g., a refrigerated dried fig or two as an alternative to candy for a sweet
Andrew Siegel, M.D.
Author of Promiscuous Eating: Understanding and Ending Our Self-Destructive Relationship with Food
Now available on Amazon Kindle