Building Out a Plant-Forward Diet

Authors: Ali Schultheis, Dr. Andrew Thorne-Lyman, Dr. Pablo Monsivais, Dr. Kate Schneider, Dr. Namrata Sanjeevi and Dr. Martine Perrigue

Throughout this Soil to Society series, we’ve discussed the grant’s goal of breeding varieties of wheat, barley, quinoa, buckwheat, lentils, and peas that are more nutritious and making new, desirable foods with them. Now what about the “Society” side of Soil to Society? The Population Nutrition and Social Science team is answering society-level questions by exploring consumption behaviors, their implications for human nutrition, and identifying strategies to get Americans to eat more of the adapted target crops.

The 2020-2025 Dietary Guidelines for Americans stress the need to incorporate a diversity of whole, plant-based foods in modern diets. Currently, more than 80% of Americans do not meet the recommended servings of legumes, which include dried peas and lentils, and more than 97% do not meet the whole grain recommendation, which ranges from three to five servings of whole grains per day for adults.

But why meet the recommendations? Incorporating more whole grains improves the intake of fiber and micronutrients, which alter the gut microbiome and are hypothesized to lead to positive health outcomes (Mayta-Apaza et al 2018, ALJahdali et al 2017, O’Keefe et al 2015). This theory will be further explored by the Human Health and Nutrition Team. Peas and lentils also contribute to this fiber intake and are healthy, affordable, and sustainable sources of protein.

How do whole grains and legumes feature in the American diet?

Using data from the National Health and Nutrition Examination Survey (NHANES), project researchers are evaluating consumption patterns of the study’s target crops by different social and demographic groups. They are also estimating the potential nutritional impacts of increasing whole grain and legume-based foods in the diet using modeling approaches. Their analysis addresses the following questions:

1. How do whole grains and legumes contribute to nutrient intake, dietary diversity, and overall dietary quality in the American diet?
2. And how can whole grains and legumes impact dietary quality if used to replace less nutritious foods in the diet?

Researchers are examining differences in dietary patterns, including diet quality, protein intake, and consumption of vegetarian diet, between consumers and non-consumers of target crops. The research also involves identifying the eating occasion, individual foods, and food sources of each of our target crops. Then, they conduct three simulation studies to explore the potential impacts of replacing less-healthful foods with whole grains and legumes; creating scenarios in which cooked whole grains replace refined grains and assessing the impact of selectively replacing meat products with legumes and legume-based foods. Finally, they conduct statistical analysis to characterize the intake of whole grains and evaluating overall dietary quality to determine whether the substitution models result in substantive change in nutrient intake or dietary quality.

How much money do Americans spend on these foods?

There are many variables to consider when analyzing consumer behavior, notably important of which is the price of the product. The second phase of work conducted by the Population Nutrition and Social Science team looks at:

1. How do households allocate food expenditures on whole grain food products?
2. And how do household food expenditures reveal consumer valuation of whole grain-based foods?

The first question is explored by measuring food spending among US households, stratified by sociodemographic characteristics, food assistance participation, and geographic region. Next, they develop economic models to estimate how consumers make trade-offs between nutritional and non-nutritional characteristics such as ingredient, fiber, plant-based content, convenience, and nutrient profile of the purchased product. Using data from the USDA Economic Research Service and Food Nutrition Service Initial Food Acquisition and Purchase Survey and the IRI household-based scanner data, project researchers develop models to identify important determinants of consumer demand for whole grain-based foods.

Are Americans willing to pay for whole grains and legumes? What could encourage more consumption?

To develop effective approaches that can help spur the dietary changes outlined in the US dietary guidelines, it is important to better understand how different populations throughout the US perceive the benefits and challenges associated with purchasing, preparing, and consuming products containing whole grains and pulses and their motivations related to dietary change. With this in mind, the Population Nutrition and Social Science team is conducting a national survey, choice experiment, and qualitative study. They will use discrete choice experiments, a method that asks survey participants to choose between two foods (see figure below) to better understand the relative importance of nutritional considerations, health-related attributes, environmental sustainability, taste and cultural preferences, ease of food preparation, and other factors in decision-making. Qualitative research will follow to explore consumer choices in greater detail.

Do people like these foods?

Without a consumer preference for these foods, there is little chance for adoption. In a human clinical trial project researchers recruit participants and test intake, acceptance, compliance, and health outcomes using prepared, heat-and-serve whole grains and legumes processed using MAPS and MATS technologies utilized by the Food Science Team.

Utilizing the information developed by the preceding Soil and Cropping Systems, Plant Breeding, and Food Science teams, the Population Nutrition and Social Science team is working to understand what motivates consumers to purchase and consume certain food products, and how our grant can create products and strategies to integrate them into US diets.

Soil to Society

The Soil to Society grant is funded through the U.S. Department of Agriculture’s National Institute of Food and Agriculture’s Sustainable Agricultural Systems (SAS) program. The SAS Soil to Society project involves over 20 researchers from Washington State University and Johns Hopkins University and evaluators from Kansas State University to improve the soil quality where these crops are grown, develop more nutritional varieties and products that can be brought to market, and evaluate the impact of these foods on human health. By bringing together soil scientists, plant breeders, food scientists, and health researchers, the Soil to Society grant crosses disciplines to develop holistic agricultural management strategies and healthy, affordable food products to meet the needs of diverse individuals and communities.

This article is part of a series on the Soil to Society project. This series explores the work of each project team, highlighting the different areas of collaboration across disciplines that work this project toward its common goal of creating a healthier food system and human population. Articles in this series are released monthly- mark your calendars for Tuesday, October 24th so you don’t miss the next one.

References:

Mayta-Apaza AC, Pottgen E, De Bodt J, et al. Impact of tart cherries polyphenols on the human gut microbiota and phenolic metabolites in vitro and in vivo. J Nutr Biochem. 2018;59. doi:10.1016/j.jnutbio.2018.04.001

ALJahdali N, Gadonna-Widehem P, Delayre-Orthez C, et al. Repeated Oral Exposure to N-Carboxymethyllysine, a Maillard Reaction Product, Alleviates Gut Microbiota Dysbiosis in Colitic Mice. Dig Dis Sci. 2017;62(12). Doi:10.1007/s10620-017-4767-8

O’Keefe SJD, Li JV, Lahti L, et al. Fat, fibre and cancer risk in African Americans and rural Africans. Nat Commun. 2015;6. doi:10.1038/ncomms7342