Protein currently enjoys a high profile in consumer food preferences, but the best dietary choice is to eat a balanced diet, according to Glenn Gaesser, PhD, director, Healthy Lifestyles Research Center, and professor, Arizona State University, Tempe. In this exclusive Baking & Snack Q&A, this expert describes the place of protein and carbohydrates in providing energy for daily living and for exercise and sports. Dr. Gaesser is a spokesman for the Grain Foods Foundation.
Baking & Snack: Given that conventional baked foods (bread and rolls) generally contain around 10% protein, how do they fit into today’s market where consumers have gone protein crazy?
Glenn Gaesser: The current US Dietary Guidelines suggest that adults should consume between 10 to 35% of total calories as protein. So baked foods, at around 10%, are in that range, albeit the low end. But Americans also consume a lot of foods (e.g., meat, eggs, dairy products) that are much higher in protein. On a balanced diet, this will ensure that protein needs are being met. Excessive protein intake is unwarranted.
How does the protein in grain-based foods stack up in Protein Efficiency Ratio (PER)?
The protein efficiency ratio (PER) is less for grain products compared to protein-rich sources such as dairy and most meat products. However, if a person consumes a balanced, mixed diet that includes sufficient quantities of protein-rich foods (e.g., dairy, eggs, meat), the PER of an individual food, or food group, is not that important. The major value of grains (particularly whole grains) is not the protein but rather all the minerals, vitamins, fiber and phytochemicals in grains that are not obtained in the traditional protein-rich foods.
Diabetes educators recommend balancing carbohydrate intake by eating protein at the same meal. Would it be effective, therefore, to raise the protein level of carbohydrate-rich grain-based foods?
I doubt it. Balancing carbohydrate intake with more protein at the same meal can very easily be done by including a food that is high in protein at the same meal. Raising the protein level of grains might help, but it might not be worth the effort. Additionally, by including a variety of foods from different food groups, a person is better positioned to meet his/her micronutrient needs.
As an expert in sports nutrition, how do you see the carbohydrate vs. protein debate? Might it also be approached as a carbohydrate-protein collaboration?
Carbohydrates are essential for exercise and sports that require a vigorous effort. Low-carbohydrate, high-protein diets can provide adequate energy for activities of daily living and for exercise and sports that require only light-to-moderate intensity effort, but carbohydrates are essential for optimal performance in high-intensity exercise and endurance sports that require sustained, near maximal efforts. In fact, high-protein diets have been shown to impair high-intensity exercise performance due to excessive acid build-up in the blood, which reduces exercise tolerance.