Project : USDA ARS

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Research Project: Dietary and Physical Activity Guidance for Weight Loss and Maintenance

Location: Healthy Body Weight Research

2022 Annual Report

Objectives
Objective 1: Determine the efficacy of a DGA-style diet combined with DGA-recommended exercise, as well as individual differences on alterations of physiological and psychological factors associated with successful weight loss and maintenance. Sub-objective 1A: Determine whether consumption of the DGA weight loss diet will produce a greater reduction in CLGI than weight loss when reducing calories with the Western diet. Sub-objective 1B: Determine whether consumption of the eucaloric DGA diet will produce a greater reduction in CLGI than the eucaloric Western diet. Sub-objective 1C: Determine whether executive function training will reduce impulsive responses to, valuation of, and attention for energy-dense foods. Sub-objective 1D: Determine whether executive function training will result in greater weight loss maintenance over 6 months than usual follow-up care. Objective 2: Test individual differences in the efficacy of dietary intake patterns and exercise to promote healthy metabolic and ingestive behavioral responses. Sub-objective 2A: Determine the independent and synergetic effects of diet and PAGA-recommended amounts of physical activity on metabolic flexibility. Sub-objective 2B: Determine the association between dopamine (DA) release as measured by electroretinography (ERG) and food reinforcement. Objective 3: Determine the relationships among exercise, dietary intake, inflammation, fitness, and behavior motivation. Objective 4: Determine the role of fat mass, fat-free mass, resting metabolism (RMR), and cellular signals on behavior motivation and appetite control.

Approach
The Dietary Guidelines for Americans (DGA), which include the Physical Activity Guidelines for Americans (PAGA), is the primary U.S. government resource for weight control. We propose that chronic, low-grade inflammation (CLGI) limits weight control by acting upon physiological and behavioral factors that moderate weight control. Diet and exercise reduce CLGI and provide weight control, but no one has investigated the efficacy of the DGA and PAGA to reduce CLGI, whether reduced CLGI promotes greater weight control, and the moderating roles of physiological and behavioral factors on the association of reduced CLGI with weight control. This study will test DGA- and PAGA-induced changes in CLGI and weight control. We will also determine the relation of change in CLGI with changes in novel putative physiological (metabolic rate, cell signaling molecules) and behavioral (food and exercise reinforcement, executive function) factors on the association of reduced CLGI that moderate weight control efficacy. To accomplish this, we will conduct a 9-month trial in 224 obese adults; a 3-month controlled feeding trial with four dietary treatment arms; 1) DGA with weight loss, 2) Western diet with weight loss, 3) DGA diet weight maintenance, 4) Western diet weight maintenance. Each dietary arm will have PAGA-recommended exercise and non-exercise arms. Post-trial is a 6-month weight maintenance period with participants randomized into executive function training intervention or control. The results will inform the DGA and PAGA; thereby helping clinicians, public health workers, and policymakers to improve the health of Americans.

Progress Report
Objectives 1 – 4: ARS scientists in Grand Forks, North Dakota, are determining, for the first time, the health and behavioral responses of consuming a diet that meets the Dietary Guidelines for Americans and engaging in physical activity that meets the Physical Activity Guidelines for Americans. The clinical study protocol was developed, and Institutional Review Board approval was obtained. Due to COVID19, recruiting for the study was halted. In consultation and approval from the office of Human Nutrition National Program 107, we have developed an online executive function training paradigm to promote fruit and vegetable consumption and decrease consumption of high sugar/high fat foods to be conducted in fiscal year (FY) 23-24. This project involves the development of an online executive function training program to alter attitudes and perceptions of consuming fruits, vegetables, and high fat/high sugar energy-dense foods. We will test the efficacy of the executive function training program titled ‘EFfect-food choices’ to improve attitudes, perceptions, and consumption of fruits and vegetables while concurrently decreasing consumption high fat/high sugar energy-dense foods. The protocol will be submitted for Institutional Review Board review and approval Fall 2022. In consultation and an approval from the office of Human Nutrition National Program 107, it was determined that in person human clinical studies that was designed for a full five-year period will be revised and conducted during the next Project Plan cycle. In alignment with National Program 107, Component 1: Linking Agricultural Practices and Beneficial Health Outcomes, ARS scientist in Grand Forks, North Dakota, are participating in the ARS Grand Synergies project ‘Beef Systems Grand Challenge’ to evaluate how breed, environment, and management practices impact the nutritional quality of beef. We have received 805 beef samples and are currently processing the samples for analyses of fatty acid and amino acid content. This research will benefit beef producers and consumers and contribute to our understanding of the role of beef cattle production on beef’s nutritional quality. In alignment with Objective 1, ARS scientists in Grand Forks, North Dakota, are testing the efficacy of two patterns of daily protein intake to promote healthy changes in body composition and dietary adherence during weight loss in overweight and obese women of childbearing age. For one group, daily protein is evenly distributed among breakfast, lunch, and dinner (30 g at each meal). For the other group, dietary protein distribution represents a typical protein eating pattern in which the majority of protein is consumed with the evening meal (10g at breakfast, 15g at lunch, 65g at dinner). To date, 34 participants have completed the study and recruitment has begun for the remaining 12 participants needed to complete the study. Preliminary results show that evenly distributing dietary protein throughout the day results in women being more satisfied with their dietary food choices and improves eating behaviors that support better adherence to a weight loss diet. These preliminary results indicate that eating 30g of protein at each meal is advantageous to women when trying to lose weight. In alignment with Objective 1, ARS scientists in Grand Forks, North Dakota, in collaboration with investigators from the Dairy Checkoff Program, are using data from the National Health and Nutrition Examination Survey to assess differences in dairy food intake among Americans by age and by ethnicity and how intake aligns with recommendations from the 2020 Dietary Guidelines for Americans. In alignment with Objective 1, ARS scientists in Grand Forks, North Dakota, are determining the feasibility of obtaining all essential nutrients from vegan diets and from a range of vegetarian diets (ovo-vegetarian, lacto-vegetarian, pescatarian) adapted from the Healthy Vegetarian Eating Pattern from the 2020 Dietary Guidelines for Americans during pregnancy and during lactation. In alignment with Objective 2, ARS scientists in Grand Forks, North Dakota, are investigating the effects of two patterns of daily protein intake on energy metabolism and fat oxidation in healthy weight individuals. For one group, daily protein is evenly distributed among breakfast, lunch, and dinner (30 g at each meal). For the other group, dietary protein distribution represents a typical protein eating pattern in which the majority of protein is consumed with the evening meal (10g at breakfast, 15g at lunch, 65g at dinner). To date, 18 participants have completed the study and recruitment has begun for the remaining 2 participants needed to complete the study. Preliminary results show that consuming a large high-protein meal in the evening promotes greater fat oxidation and energy metabolism compared to multiple moderate protein and energy containing meals. In alignment with Objective 3, ARS scientists in Grand Forks, North Dakota, completed an internet-based clinical study investigating how information source (control—no source, USDA, fictitious hospital, or fictitious social media) impacts perceptions of diet information. Greater than 500 participants completed an online survey in which they were presented a flyer containing dietary guidance, health, and information about consuming pulses. They then answered questions regarding their perceptions of the flyer’s accuracy, how trustworthy and reliable the source was, their interest in learning more, and their likelihood of following the dietary guidance. The USDA and hospital sources were perceived as more accurate, trustworthy, reliable, and more desirable to learn more from relative to control and social media. There were no differences in likelihood of following guidance depending on source. Overall, these findings suggest that trust in the source of information does not influence perceived likelihood of following dietary recommendations for pulses. In alignment with Objective 3, ARS scientists in Grand Forks, North Dakota, in collaboration with investigators from five Universities across the United States identified the factors that help create “Positive Deviants”—rural communities with greater physical activity than their peers. Stakeholder interviews, intercept interviews, and on-site observations revealed that Human and Organizational Capital differed between the high-physical activity and low-physical activity Counties; manifesting as Social, Built, Financial, and Political Capital differences and a possible “spiraling-up” or cyclical effect through increasing physical activity and health (Human Capital), highlighting a potential causal model for future study. Multi-organizational physical activity coalitions may hold promise for rural physical activity by influencing Human and Organizational Capital in the short term and the other forms of capital in the long term. In alignment with Objective 4, ARS scientists in Grand Forks, North Dakota, are determining the differences in release of signaling molecules from fat cells (adipokines) and muscle cells (myokines) in exercise-trained and untrained adults following low- and high-intensity exercise. The clinical trial was developed, Institutional Review Board approval obtained, and the study initiated with two participants completing the required treatments before being halted due to the COVID-19 pandemic. The research restarted June 2022 and eight participants have been enrolled. This research will aid in determining how exercise-induced myokine and adipokine secretion influences the chronic low-grade inflammation that promotes cardiovascular and other diseases. In alignment with Objective 4, ARS scientists in Grand Forks, North Dakota, are also determining the differences in release of signaling molecules from fat cells (adipokines) and muscle cells (myokines) before and after six weeks of exercise training. The concentration of these signaling molecules will be tested for their associations with the pre-to-post exercise training change in discomfort felt during exercise and the motivating value of exercise. Samples from a previous study are being sent to a commercial laboratory for analysis.

Accomplishments
1. Eating vegetables improves diet quality and increases happiness. Recent evidence suggests that in addition to all the known health benefits eating more vegetables may exert a positive effect on how happy a person feels. Still, getting people to eat the recommended amount of vegetables is difficult. As such, it is important to understand what happens to a person’s diet and happiness when they eat more vegetables. ARS scientists in Grand Forks, North Dakota, tested how the provision of the amount and types of vegetables recommended by the Dietary Guidelines for Americans (DGA) changed the diet of overweight and obese adults and if eating more vegetables exerted a positive effect on how happy they felt. Scientists found that increasing the amount of vegetables in the diet decreased how much grains, protein foods, saturated fats, and added sugars were consumed. Some of the foods reported being displaced by the vegetables were snack foods, bread, and soda. As such, diet quality and the energy density of the diet improved. In addition, eating the provided vegetables every day increased feelings of happiness. This finding was independent of how happy of a person felt at the beginning of the study. These findings suggest that adhering to DGA vegetable guidance may help promote a more healthful diet and psychological well-being.

2. Defining healthy dairy-free vegetarian or vegan diets. The 2020 Dietary Guidelines for Americans (DGA) describes a healthy vegetarian diet. But the DGA does not say how vegans and vegetarians who do not eat dairy can have a healthy diet. An ARS scientist in Grand Forks, North Dakota, tested different versions of the DGA vegetarian diet. One of these versions replaced dairy with soy milk and soy yogurt. The vegan version also replaced dairy with soy. It also replaced eggs with beans, nuts/seeds, and soy products. These new vegetarian patterns provided enough nutrients for most Americans. However, there was not enough zinc for males who are over 50 years of age. The vegetarian pattern in the 2020 DGA can be adapted for dairy-free vegetarian and vegan diets and still meet nutrition recommendations for most healthy adults.

3. Active videogames to promote traditional active play. Physical activity is important for overall health of children and helps to set a lifetime habit. Still most children are not active enough to gain these benefits. So, it is important to understand how to increase children’s motivation to be more active. ARS scientist in Grand Forks, North Dakota, tested whether repeated exposures of fun physical activity (Active videogames (AVG)) would increase physical activity reinforcement of children. Ideally, AVG play would transition to non-screen-based active play such as traditional active play (TAP). AVG play increased the reinforcing value of AVG compared to sedentary videogame (SVG) and to TAP. This research is the first demonstration of increasing physical activity reinforcement in children and is important to nutrition scientists, physical activity scientists, health professionals, and the American consumer.

4. Positive deviants for physical activity. Rural U.S. communities experience health disparities, including a lower prevalence of physical activity (PA). ARS scientists in Grand Forks, North Dakota, in collaboration with investigators from five Universities across the United States identified the factors that help create “Positive Deviants”—rural communities with greater physical activity than their peers. Stakeholder interviews, intercept interviews, and on-site observations revealed that Human and Organizational Capital differed between the high-physical activity and low-physical activity Counties; manifesting as Social, Built, Financial, and Political Capital differences and a possible “spiraling-up” effect through increasing physical activity and health (Human Capital), highlighting a potential causal model for future study. Multi-organizational physical activity coalitions may hold promise for rural physical activity by influencing Human and Organizational Capital in the short term and the other forms of capital in the long term. This research is important to rural health practitioners, physical activity scientists, health professionals, and the American consumer.

U.S. DEPARTMENT OF AGRICULTURE

Healthy Body Weight Research: Grand Forks, ND