When I began reading the U.S. News & World Report article, I was pleasantly surprised. The nutritional theories being espoused made perfect sense, even though the sensationalist cover line that initially caught my attention ("Eat more, lose weight") made me skeptical. The take-home message was, in fact, one that I had figured out many years prior: Different foods are vastly different when the energy contained per unit of their volume is considered.
The article revealed information about Pennsylvania State University's Laboratory for the Study of Human Ingestive Behavior, cited as "one of the world's most sophisticated centers for the study of what and how humans eat." The lead researcher at the lab is Barbara Rolls, professor and Guthrie chair in nutrition at the college. Rolls&Mac226; recent investigations have focused on the impact of energy density of foods (the number of calories in a given volume of food) on satiety and weight control.
Through her research, Rolls has observed a number of important hunger and eating-related behaviors that might shed light on why obesity is so prevalent. She realized, for example, that satiety is food specific: People may crave one particular food, even though their hunger has been satisfied after having consumed enough of another. She also observed that humans eat about the same volume of food each day even if there is considerable day-to-day variation in the amount of energy that their choices contain. Consequently, satisfying a similar urge to eat on two separate days might involve the ingestion of a considerably different quantity of calories, depending on the actual choices that are made. People also appear to eat more food when more is available. Rolls has labeled her research "Volumetrics."
How can understanding Volumetrics help us lose body fat? If the amount of energy you ingest depends primarily on the particular food choices you make with volume consumed a lesser consideration, assuming a relatively small day-to-day fluctuation, it's only logical that some lengthy consideration be given before we decide what to put on our plate. This requires knowing how many calories are contained in the foods we eat. If we can figure out how to eat the amount of food that satisfies our quantity-dictated comfort level while ingesting less energy than we expend throughout our day, we're good to go!
Rolls compares the distinction between foods on opposite ends of the energy-density spectrum and those that fall under the good and bad food heading (potato chips versus a baked potato, for example). Obviously, if you are limiting yourself to a certain number of calories for a given meal, opting for the baked potato is advantageous because you can eat a greater quantity and end up more satisfied. But this should come as no surprise: Everyone knows it's a good idea to avoid "junk" foods which are energy-rich and nutrient deficient. But what about foods that don't fall under this heading? In my opinion, considerable thought should go toward differentiating between "good" foods as well.
Just because a food might be considered a good choice when nutrition is the primary concern, it doesn't mean it is the best bet if you're trying to get the most food for the least energy. Rolls recognizes the benefits of pasta which absorbs a considerable amount of water as it cooks compared to Italian bread, which has similar ingredients, but is not as water rich. This lack of water content means you can't eat as much Italian bread if your aim is to ingest a specific number of calories.
But I like to take this comparison one step further. As a carbohydrate advocate, I frequently sing the praises of pasta. It is, however, relatively dense in energy compared to some other complex carbs. So, even though it is what should be considered a healthy food, you can't simply put a similar quantity of it on your plate as you would another good carbohydrate food (baked potatoes, for example) and expect the energy contained in the two portions to be similar. And if you do actually count calories and limit yourself to a specific quantity, you'll realize that if you're hungry after eating a certain amount of calories of pasta, there are other options that would allow you to eat for a longer period of time and leave the table more satisfied.
Rolls has devised a formula to put all of this into perspective. According to Volumetrics, if you check out a food label, keep in mind there are two critical numbers to consider: calories and serving size according to weight. If you divide the calories in one serving by its weight in grams, the quotient represents a numerical quantification of how energy-dense a food is.
Foods like pasta, whose serving-size weight is expressed uncooked, must be adjusted by determining how much the food weighs after preparation. If you get a number greater than two, you might want to reconsider choosing that food, even if it's nutrient-dense and contains little saturated fat or cholesterol, simply because you won't be able to eat as much of it if you're restricting yourself to a particular level of energy ingestion.
Fred Dimenna, a Certified Strength and Conditioning Specialist and lifestyle and Weight Management Consultant is a two-time Natural Mr. United States and a WNBF drug-free professional bodybuilder. Visit him at www.freddimenna.com or email him: firstname.lastname@example.org