By Marie Spano, M.S., R.D., C.S.C.S.
Contributing Editor
It’s no secret that America is on a mission to lose weight. According to 2005 to 2006 statistics from Centers for Disease Control and Prevention, Atlanta, more than one-third of American adults are obese. Although the bottom line often boils down to the calorie-balance equation—eating too many calories and not getting enough physical activity—there are certain macronutrients and food components that are more filling than others, satiating the appetite so people eat less throughout the day.
“The issue of weight management is a significant concern for many people, so controlling hunger can be an appealing message to consumers,” says Laura Gottschalk, vice president, U.S. manufacturing and ingredient marketing, Dairy Management Inc.™ (DMI), Rosemont, IL.
Though the low-carb, high-protein diet craze has come and gone, protein still stands out as a key macronutrient in the war against weight loss. “While the value of protein to promote satiety is not a new discovery, it is receiving much more interest as consumers, governments and researchers seek solutions to the growing global crisis around obesity,” says Michele Fite, vice president, global strategy and marketing and specialty business, Solae, St. Louis. “High-quality protein—e.g., milk, eggs, lean meat and soy protein—as research supports, is playing a key role in new food-product development to help deliver these solutions. We see a strong demand for soy protein to be incorporated into more of a variety of food applications, including bars, nutritional drinks, cereals, breads, and bakery products.”
The power of protein
Both animal and human studies show that consuming protein, as compared to carbohydrate and fat, promotes stronger feelings of satiety and suppresses food intake at the next meal. In humans, visual analogue scales (which use a scale to measure how hungry a person is) and food intake are often used to measure satiety. In addition, changes in hormone levels that affect appetite can provide a closer look at how the three macronutrients impact satiety and hunger. Cholecystokinin (CCK) is an intestinal hormone that is released after a meal and signals satiety. Increased levels of peptide YY (PYY) signal satiety, and ghrelin levels increase when we are hungry. In addition to altering our feelings of satiety, protein-rich meals stimulate CCK and inhibit ghrelin, providing a biological explanation for how protein works to influence satiety.