Last week we discussed energy in food in terms of caloric density. Below are some important reminders as we continue talking about energy in food, particularly regarding calorie absorption.
To put it simply: the weight-loss equation is a matter of balancing the amount of energy coming in with the energy going out. If you have more energy or food coming into your body than going out, you gain weight. If you have more energy going out in terms of exercise than you have coming in as food, you lose weight.
Caloric density refers to the number of Calories in a given weight of food. Foods high in caloric density have a larger number of Calories in a measured weight of food, and foods low in caloric density have fewer calories in the same measured weight of food.
Fat: 9 Calories per gram
Alcohol: 7 Calories per gram
Protein: 4 Calories per gram
Carbohydrate: 4 Calories per gram
Caloric Density Scale
Vegetables: 60-195 calories per pound
Fruit: 140-420 calories per pound
Potatoes, pasta, rice, corn, hot cereals: 320-630 calories per pound
Beans, peas, lentils: 310-780 calories per pound
Breads, bagels, muffins, dried fruit: 920-1,360 calories per pound
Granulated sugar. honey, corn syrup, agave, maple syrup: 1,200 -1,800 calories per pound
Dry cereals, chips, crackers: 1,480-3,200 calories per pound
Nuts and seeds: 2,400-3,200 calories per pound
Oil: 4,000 calories per pound
Think of your stomach as a box that you fill with things. If that box can hold three pounds of food and you fill it with sugar, nuts and seeds, and oil, it can have 9,000 calories in it. If you fill that box with fruits, vegetables, and potatoes, it would be more like 900 calories.
Aside from caloric density, the speed at which food, specifically the sugar in food, is absorbed is also important. One standardized measure of how quickly different foods are metabolized and affect blood sugar is called the glycemic index (GI). The GI measurement seeks to eliminate everything but the precise food being measured. The Academy of Nutrition and Dietetics explains that “the glycemic index doesn’t take into account how much we’re actually consuming. The GI value of a food is determined by giving people a serving of the food (on an empty stomach) that contains 50 grams of carbohydrate minus the fiber, then measuring the effect on their blood glucose levels over the next two hours. A serving of 50 grams of carbohydrate in one sitting may be reasonable for a food such as rice, which has 53 grams of carbs per cup. But for beets, a GI ranking of 64 is a little misleading since beets have just 13 grams of carbs per cup; we would need to consume nearly 4 cups of beets in order to cause that spike in blood sugar levels.” The unrealistic thing about the GI is that it doesn’t reflect how humans eat. Protein, fat, and especially our good friend fiber all serve to reduce the overall GI of a meal. The GI is helpful but imperfect.
Low GI Foods: <55 on the GI Scale
Medium GI Foods: 56-69 on the GI Scale
High GI Foods: >70 on the GI Scale
Detailed glycemic index charts are widely available online.
In contrast to the glycemic index (GI), the glycemic load (GL) “is a formula that corrects for potentially misleading GI by combining portion size and GI into one number. The carbohydrate content of the actual serving is multiplied by the food’s GI, then that number is divided by 100. So for a cup of beets, the GL would be: 13 times 64 = 832 divided by 100 = a GL of 8.3.”
Low GL Foods: <10 on the GL Scale
Medium GL Foods: 11-19 on the GL Scale
High GL Foods: >20 on the GL Scale
Detailed glycemic load charts are widely available online.
Foods that have a low GI but you generally eat more of will have a low GI but a high GL. For example, potato chips have a low GI of 54 and a high GL of 30. Alternatively, foods that have a high GI, but you generally eat less of, have a high GI and a low GL: watermelon has a high GI of 72 and a low GL of 8.
The GI and GL are not perfect systems, but they can both be used to identify foods that are higher in refined carbohydrates and void of fiber. Thinking about food in terms of balancing GI, GL, caloric density, and satisfaction can help you select the proper portions of food that are low in caloric density but provide high levels of satisfaction. The easy way around all of the figuring and counting is to eat the whole foods plant-based diet our bodies were developed to eat. That’s the healthy weight-loss meal plan you don’t have to think about!
Here is the reference for today’s healthy eating tip.
Academy of Nutrition and Dietetics. Food. Nutrition. Dietary Guidelines and MyPlate. What Is the Glycemic Index? https://www.eatright.org/food/nutrition/dietary-guidelines-and-myplate/what-is-glycemic-index (Accessed 6/17/2021).