Project Committee on Protein Pre-proposal Request for Research: How Changes in Ad Libitum Dietary Protein Affect Nutrient Adequacy and Diet Quality

1 December 2017


There is accumulating evidence that protein intakes above the Recommended Dietary Allowance (RDA) may reduce chronic disease risk (e.g., obesity, osteoporosis, sarcopenia) and improve quality of life in older adults. (1) Several mechanisms have been proposed whereby protein may support these benefits, one of which is the presence of essential nutrients in protein-containing foods. (2) It is known that both animal- and plant-based proteins contribute unique nutrients, several of which are under consumed by a large proportion of the population (i.e., nutrients of concern). Modeling studies have shown that dietary protein intakes above the RDA are more likely to meet the target for these nutrients and others, importantly at more modest energy intakes. 2 In addition, certain population subgroups are being encouraged to decrease protein intakes (e.g., adolescent boys and adult men). (3) In a recent study, participants with type 2 diabetes selected a lower quality diet when advised to avoid eggs at breakfast as part of an intervention study. (4) Specifically, intakes of refined grains increased at the expense of protein foods. Whether similar findings would be observed when examining displacement of protein-containing foods in general warrants further study. This study aims to evaluate overall diet quality under freeliving conditions in the context of a higher protein versus a normal protein ad libitum diet.

1Phillips SM, Chevalier S, Leidy HJ. Protein "requirements" beyond the RDA: implications for optimizing health. Appl Physiol Nutr Metab. 2016;41:565-72.
2Phillips SM, Fulgoni VL, Heaney RP, et al. Commonly consumed protein foods contribute to nutrient intake, diet quality, and nutrient adequacy. Am J Clin Nutr. 2015;101(Suppl):1346S-52S.
3U.S. Department of Health and Human Services and U.S. Department of Agriculture. 2015–2020 Dietary Guidelines for Americans. 8th Edition. December 2015.
4Njike VY, Annam R, Costales VC, Yarandi N, Katz DL. Which foods are displaced in the diets of adults with type 2 diabetes with the inclusion of eggs in their diets? A randomized, controlled, crossover trial. BMJ Open Diabetes Res Care. 2017;5(1):e000411.

Determine the impact of dietary protein displacement on nutrient adequacy and diet quality.

Analyze dietary data from intervention studies in which ad libitum higher-protein diets were compared to ad libitum normal-protein diets under free-living conditions.

Study Hypotheses

  1. Adult subjects increasing protein intake improve nutrient adequacy (or vice versa for studies in which the intervention decreased protein intake).

  1. Adult subjects substantially increasing protein intake improve overall diet quality (or vice versa for studies in which the intervention decreased protein intake), based on a validated healthy eating index. Analysis should include a breakdown of the index components (e.g., food groups) in order to explain the underlying basis for a change in overall diet quality.

Additional Considerations and Clarifications

  • Pre-proposals should be clear about the generalizability of proposed analysis to the general North American public, choice of eating index, and primary aim of the original intervention (e.g., weight loss, muscle retention/building- ).

  • Secondary analysis can be proposed for recently completed, on-going and starting-up prospective intervention Dietary intake or the background diet should reflect current eating patterns?

  • Special populations, like vegetarians, morbidly obese with BMI 35+, or people managing a disease like heart disease or diabetes, would not reflect the general population and therefore will not be considered.

  • However, study interventions could include weight management, glycemic response, cardiovascular risk, bone, body composition, physical performance, and other health outcomes testing self-selected added or reduced protein in the diet.

Pre-Proposal Submission due January 30, 2018

The Committee requests that applicants respond to each of the questions below in no more than 2 pages total (minimum 11 point font, single space). Top proposals meeting the criteria will be invited to submit a project proposal. Contents of the pre-proposal are described here briefly. A template for pre-proposals is provided for convenience on the template indicated above, but is not required.

Overview: Describe in 2-3 sentences your approach.

Hypothesis statements (primary and secondary)

Data to be used: Describe the data you plan to use noting the key strengths relative to your specific hypothesis and addressing how you will manage limitations.

If you are able to combine data from multiple intervention studies to improve generalizability, be sure to note that.

Describe how subject demographics relate to the general public, years in which data were collected, dietary intake assessment method, dietary intervention, degree to which protein intake was changed during the intervention, compliance measures, and the primary intervention outcome aim (e.g., weight management).

Outcomes: State the specific outcomes to be reported, including how protein intake and change will be expressed, specific nutrients to be reported, how nutrient adequacy will be measured, and the healthy eating criteria and measure to be used.

Budget and Timeline: Acknowledge with a rough budget range projection that the research would be completed for less than US $25,000 (inclusive of all costs including overhead which is capped at 10%) and within one year after an agreement is signed, including submission of the manuscript for publication and posting supporting data as appropriate. ILSI NA policy requires data be made accessible and research published. Ideally, a project would be funded that combines results from more than one intervention to increase generalizability and return on research investment costs. In this case, budgets can be itemized separately for co-investigators in the proposal as long as the total budget is within the limit. Two or more small grants may also be feasible.

Pre-Proposal Submit and Review Process
Submit pre-proposals by email to Barbara Lyle, PhD at with a copy to Angela Roberts ( by end of day January 30, 2018.

A working group of ILSI NA staff and protein committee members, which is comprised of industry, government, and academic scientists, will review pre-proposals and invite PI’s with pre-proposals most clearly aligned to submit a full proposal. Key deciding factors will be: 1) relevance to current general healthy population, 2) effective intervention leading to increased/decreased protein intake, 3) quality dietary intake data, and 4) high potential to be accomplished within budget and on time.

About ILSI and ILSI North America
The International Life Sciences Institute (ILSI): Founded in 1978, the International Life Sciences Institute (ILSI) is a nonprofit, worldwide foundation that seeks to improve the well-being of the general public through the advancement of science in the areas of nutrition, food safety, toxicology, risk assessment, and the environment by bringing together scientists from academia, government, and industry.

Headquartered in Washington, DC, ILSI accomplishes this work through its worldwide network of fourteen branches, its Research Foundation (ILSI Research Foundation) and ILSI Health and Environmental Sciences Institute (ILSI HESI), which has a global, rather than regional, focus.

ILSI North America: ILSI North America is a nonprofit organization based in Washington, D.C., that provides a forum for academic, government, and industry scientists to identify important issues in nutrition and food safety. Through its programs, ILSI North America contributes to improve scientific understanding of those issues for the benefit of the general public. For more information on ILSI North America’s areas of interest, projects, staff, and a copy of the Annual Report, please visit:

ILSI North America Project Committee on Protein: This Committee seeks to further the scientific understanding of the optimal distribution of protein intake in dietary patterns for different population subgroups; this will include examination of the health benefits and risks associated with various protein intakes and the timing of their intake to achieve health benefits. To learn more about the Committee, please visit:

ILSI NA Pre-Proposal

How Changes in Ad Libitum Dietary Protein Affect Nutrient Adequacy and Diet Quality

(2 page maximum, single space, 11 font minimum)


Lead Investigator
Overview of approach (1-3 sentences)

Hypothesis statements


Data to be used (See pre-proposal request for details)

Outcomes (State specific outcomes to be reported):

  • Protein intake and change will be expressed by
  • Specific nutrients to be reported include
  • Nutrient adequacy will be measured by
  • Diet quality criteria and measure to be used are

Budget and Timeline
Estimated upper limit to costs inclusive of all direct and indirect costs including free access publication fees =

Estimated maximum length of time from agreement to submitted manuscript for publication =

Funding Source
Indicate funding source for the intervention studies to be used in this project and additional funds that would be used to support this project.

Name Affiliation (Institution and department) Disclose potential conflicts of interest (2013+)