Protein Source on Plasma Amino Acid Concentrations

The 2015-2020 Dietary Guidelines for Americans stipulates how much Protein Foods should be consumed per day and per week as part of a Healthy U.S.-Style Eating Pattern. The predominant protein sources include lean meats, poultry, and eggs, however, nuts, seeds, and soy products are also included. Ounce-equivalents (oz-eq) are used as a standard unit of measure to compare animal to non-animal protein sources. One oz-eq of lean meat (1 oz) is equal to 0.5 oz of nuts (1 oz-eq), 0.25 cups (1 oz-eq) of beans, and one whole egg (1 oz-eq). One limitation of this unit of measure is that the protein quantity and quality of the foods are not considered. For example, 1 oz-eq of pork loin contains ~7 g of dietary protein whereas 1 oz-eq of almonds contains 3 g of protein. Consequently, consuming an oz-eq portion of protein foods from different sources could have different effects on the anabolic response to feeding. The purpose of this study is to assess the effect of consuming ounce equivalent portions of fresh pork versus nuts, beans, and eggs on essential amino acid substrate availability for protein anabolism. While it would seem intuitive that this research would show that higher protein intakes from pork and egg will lead to higher plasma essential amino acid responses, this research is paramount to addressing the shortcoming of using oz-eq to achieve the Dietary Guidelines for Americans recommendations for Protein Foods. This research will serve as an important resource for future Dietary Guidelines Advisory Committees to reevaluate the appropriateness of equating animal- and plant-based Protein Foods on the current ounce-equivalent basis.

Inclusion criteria

• Male or female
• Age 25-39
• BMI 25-35 kg∙m-2
• Weight stable (± 4.5 kg) 3 months pre-study
• Not acutely ill
• Not diabetic
• Not pregnant or lactating
• Not currently (or within 3 months pre-study) following a vigorous exercise regimen
• Non-smoking
• Willing to consume study foods and travel to testing facilities.