The turkey, and the days’ worth of leftovers, enjoyed during the Thanksgiving holiday are all but forgotten by now, but research continues to remind us of the role of protein in health. In fact, the 2010 Dietary Guidelines Advisory Committee Report devoted an entire chapter to protein for the first time since the reports began being published in 1995. Protein is also featured prominently on the United States Department of Agriculture’s (USDA) new food icon, MyPlate, which replaced MyPyramid as the government’s primary icon to describe food guidance and choices. These efforts, among others, continue to raise public awareness of protein’s role as a vital macronutrient and its role in optimal health throughout the lifecycle. Protein may pack more of a punch than previously thought.
Recommendations and Research
The Institute of Medicine has established the Recommended Dietary Allowance (RDA) for protein at 0.8 g/kg body weight for adults ages 19 and older—or about 54 grams of high quality protein per day for a 150 lb. adult, regardless of gender. Dietary protein recommendations have traditionally been based on the goal of preventing deficiency, as opposed to promoting optimal health. However, research suggests that higher protein intakes may be beneficial for various health outcomes, such as weight management, maintaining muscle mass, preventing osteoporosis, and reducing the risk of cardiovascular disease.
Perceptions of Protein
In general, consumers’ positively associate protein with benefits to health, but knowledge of proteins’ benefit, beyond helping to build muscle, is limited. IFIC Foundation’s 2011 Food & Health Survey found that almost two-thirds of Americans agree that protein helps build muscle, yet only four in ten agree that protein helps people feel full. Only one in three agree that high-protein diets can help with weight loss.
What more is there to know?
There is much more known about how protein contributes to overall health than just building muscle. Take satiety for example. Satiety is the feeling of being satisfied with the type and amount of food eaten. To reach or maintain a healthy weight, it’s important to feel satisfied with the amount of calories required for that weight. Research suggests that snacks and/or meals with increased protein may increase satiety, which can aid in consuming the appropriate amount of calories per day for desired weight.
Another example of protein’s positive impact on health is its role in body composition—the amount of lean tissue (muscle) as compared to fat tissue. Generally speaking, when a pound of body weight is lost it includes about 75 percent fat mass and 25 percent muscle. However, several studies have suggested that high-protein diets may increase the percentage of body fat lost, while sparing lean muscle mass. Because muscle burns more calories than fat, increasing muscle to fat ratio can help burn more calories overall.
Protein research continues to evolve and reveal the importance of consuming protein. Although Americans have traditionally made the connection between protein and health, they have attempted to consume the majority of their protein from the dinner plate. To maximize protein’s unique contributions to health, intake should be evenly distributed across all plates (breakfast, lunch, and dinner), rather than seeking a large amount from only one. No clear conclusions have been made, but preliminary evidence in the elderly population suggests that eating about 30g of protein at a meal helps maximize muscle protein synthesis (assuming adequate total calorie intake and normal kidney function). Such a strategy may be helpful in adding protein (and satisfaction) to the diet, optimizing health, and staying within calorie needs.