Location: Healthy Body Weight Research
2017 Annual Report
Objectives
Objective 1: Identify psychological and physiological processes and factors that influence the motivation to exercise and to eat.
Objective 1A. Determine whether incentive sensitization for physical activity is dependent on the dose and the pattern/intensity of physical activity.
Objective 1B. Determine whether the level of negative energy balance influences the magnitude of alterations in food reinforcement.
Objective 2: Determine whether the relative reinforcing value of vegetables or fruits can be increased through repeated exposure.
Objective 3: Determine the effect of meal macronutrient composition on energy metabolism and substrate utilization and satiety.
Objective 3A: Compare the effects of high- vs. low-protein breakfasts as components of two patterns of daily protein intake (even distribution of protein across all meals vs. a skewed distribution with most protein consumed at the evening meal) on energy metabolism, substrate oxidation, satiety and the reinforcing value of high-sugar, after-meal snack foods.
Objective 3B: Determine the effects of consuming a sugar-sweetened beverage as part of low- (55% CHO, 15% PRO, 30% FAT) or high-protein (40% CHO, 30% PRO, 30% FAT) meals on energy metabolism and substrate oxidation, and satiety and RRV of high-sugar, after-meal snacks.
Approach
Achieving and maintaining healthy body weight underlies many critical aspects of health. The immediate choices people make about their foods and physical activities have cumulative effects that affect body weight and, ultimately, health. Yet, the motivational bases of those choices remain poorly understood; as are ways those choices may be moved towards healthier alternatives. This knowledge is needed for the development of new and effective tools to promote behavioral choices that support healthy body weight. This project addresses these needs by investigating how to increase the reinforcing value of physical activity, and ways to increase the reinforcing value of vegetables and fruits. It also will evaluate the motivating potential of providing real-time feedback on subject energy balance based on an analysis of breath. This project will yield empirical evidence that will inform dietary and physical activity guidelines and programs, and tools that can be used by workers in the health and fitness industries to help individuals make healthy choices regarding physical activity, diet, and maintenance of a healthy body weight.
Progress Report
Objective 1A.1 (Determine whether incentive sensitization for physical activity is dependent on the dose of physical activity, Objective 1A) completed subject recruitment (additional 18 subjects for a total of 108 subjects), data collection, data processing, and data analyses; wrote a paper and submitted it for peer-review. All subjects were asked to exercise train for 6 weeks to determine whether repeated exposures to exercise increased their motivation to be exercise. Subjects completed an extensive set of outcome measures at baseline, 6 weeks, and at a 12 week follow-up visit.
Objective 1A.2 (Determine whether incentive sensitization for physical activity is dependent on the pattern/intensity of physical activity, Objective 1A) developed and refined the study protocol and exercise testing and training procedures and obtained Institutional Review Board (IRB) approval; pilot tested the protocol, commenced recruitment and began the human study.
Objective 2A (Determine whether the reinforcing value of vegetables can be increased by incentive sensitization): This randomized, controlled trial will determine whether repeated exposure to Dietary Guidelines recommended amounts of vegetables will increase the reinforcing value of vegetables more than amounts currently consumed. To date, 59 participants have completed the 16-week protocol and another 18 are currently enrolled.
Objective 2B (Determine whether the reinforcing value of fruits can be increased by incentive sensitization): The human study protocol was developed and IRB approval obtained. The study will commence human subject recruitment in the fall of 2017.
Objective 3A: Data collection has begun for study 3a (Determine the effects of high- and low-protein breakfasts as components of two patterns of daily protein intake (even distribution of protein across all meals vs. a skewed distribution with most protein consumed at the evening meal) on energy metabolism, substrate oxidation and the RRV of high-sugar snack foods). Recruitment was slow to start but has significantly picked up since then. To date, one subject has completed all study procedures, 4 have completed the first half, and 1 has been scheduled to start the end of July.
Subordinate studies for Milestone 1 include:
1) Completion of a study to understand why some individuals lose more weight with exercise training than others. This study determined whether there are physiological (i.e., hormonal) and behavioral (increases in the motivation to eat, reductions in the motivation to be active, usual physical activity, usual energy intake) mechanisms that explain why some people compensate (respond) to the energy expended during exercise by eating more or being less active throughout the day resulting in no or little weight change. The study found that people expending 600 kcal/day, 5 days per week for 12 weeks in exercise had the same compensation as those expending 300 kcal/day in exercise. Thus, those expending 600 kcal/day lost weight and fat while those expending 300 kcal/day did not lose weight or fat. All 30 subjects have completed the study (18 subjects were enrolled and completed the study in FY 2017). A paper has been written and submitted for peer review.
2) A second sibling study is determining whether reducing the amount of added sugar in the diet to the level encouraged in the Dietary Guidelines for Americans increases a person’s motivation to eat sugar. Reducing some behaviors below its baseline rate can make them more motivating we are testing whether this psychobiological response (increased motivation) may be one barrier for Americans to make initial and sustained healthy behavior changes aligned with the Dietary Guidelines. 30 subjects have completed the study, but approximately another 10 obese subjects need to be recruited in FY2018. A complete, yet draft version, of the paper has been written and reviewed by all coauthors.
3) A third sibling study determined the role of the motivating aspect (i.e., attractiveness) of exercise and the liking of exercise on usual participation of exercise. We assessed 90 participants motivating value and liking of resistance and aerobic exercise, the ability to tolerate discomfort, and usual participation in these modes of exercise. Two papers were written and accepted for publication in FY17.
4) A fourth sibling study for Milestone 1 is determining whether playing active videogames increases the attractiveness of physically active play for children. Fifty participants are needed; to date 20 have finished the study and 20 participants are active in the study.
Subordinate studies for Milestone 2 include:
1) Determining the dose-response relationship between vegetable intake and skin and blood carotenoid concentrations. If it is found that skin carotenoids are responsive to changes in small amounts of vegetables consumed, it will represent a quantum change in the way that dietary interventions to increase vegetable intake are evaluated. To date, IRB approval has been obtained and this study will begin in FY17.
Subordinate studies for Milestone 3 include:
1) Testing the degree of caloric restriction required to detect a noticeable shift the in breath 13C:12C (d13C) and how much variation in breath d13C is caused by dietary fluctuations in 13C under hypo- and hyper-caloric conditions.
2) Testing the efficacy of two patterns of daily protein intake (32 en% from beef) to promote healthy changes in body composition and dietary adherence during weight loss. Subordinate study 1 - all subjects have completed the study protocol and the data are being analyzed. Subordinate study 2 - the human study protocol is developed and IRB approval has been obtained, recruitment will begin August 2017. These works extend Objective 3: Use breath analyses to determine the effect of meal macronutrient composition on energy metabolism and substrate utilization and satiety.
Accomplishments
1. Demonstrated that the motivating value of exercise is a good predictor of who will meet the physical activity guidelines detailed in the Dietary Guidelines for Americans. Most Americans do not participate in enough physical activity to meet the physical activity guidelines and therefore do not receive all of the health benefits of engaging in physical activity. ARS researchers in Grand Forks, North Dakota demonstrated for the first time that people who have greater motivation for aerobic or resistance exercise and a greater tolerance for the discomfort perceived during exercise are more likely to meet the Physical Activity Guidelines for Americans. It also showed that a greater tolerance for the discomfort perceived during exercise predicts a greater motivating value of exercise. This work will guide future research in how to increase the motivating value of exercise and help them to meet the physical activity goals detailed in the Dietary Guidelines for Americans.
2. Demonstrated that the motivating value of exercise and liking of exercise are not the same thing. Most Americans do not participate in enough physical activity to meet the physical activity guidelines and therefore do not receive all of the health benefits of engaging in physical activity. ARS researchers in Grand Forks, North Dakota demonstrated for the first time that a basic property for engaging in other reinforcing behaviors such as taking drugs of abuse, gambling, and food addiction also holds for exercise; that is, that the motivating value, but not the liking, of resistance training and aerobic exercise predicts the usual level of adults’ participation in those activities. This study demonstrates that exercise is reinforcing in humans. This work will guide future research in how to increase the motivating value of exercise and help them to meet the physical activity goals detailed in the Dietary Guidelines for Americans.
3. Demonstrated that the motivating value of exercise can be increased. Most Americans do not participate in enough physical activity to meet the physical activity guidelines and therefore do not receive all of the health benefits of engaging in physical activity. ARS researchers in Grand Forks, North Dakota demonstrated, for the first time, that aerobic exercise training for 6 weeks increased the motivating value of exercise in some adults. Increasing the motivating value of exercise should help people to develop exercise as a habit and help them to them to meet the physical activity goals detailed in the Dietary Guidelines for Americans.
4. Demonstrated why some people lose weight with exercise and some do not. One reason that exercise may not be highly motivating to people is that it does not produce the amount of weight loss that they expected it would. ARS researchers in Grand Forks, North Dakota demonstrated why some individuals lose more weight with exercise training than others. This study demonstrated that people who expended 600 kcal/day, 5 days per week for 12 weeks in exercise ate the same number of additional calories as those people who expending 300 kcal/day in exercise. Thus, those expending 600 kcal/day lost weight and fat while those expending 300 kcal/day did not lose weight or fat. This work shows that people can lose weight and fat with exercise, but that they have to expend more than 1500 calories/week and probably closer to 3000 calories/ week exercising to have meaningful changes in weight.
5. Demonstrated that drinking a sugar-sweetened beverage with a meal markedly reduces metabolic efficiency. Caloric beverages account for more than 50% of all added sugars in the U.S. diet; however, it is not known how the inclusion of a sugar-sweetened drink changes how the body used the nutrients from the meal. ARS researchers in Grand Forks, North Dakota tested metabolic responses to the inclusion of sugar-sweetened drink with meals containing 15% or 30% protein. Drinking a sugar-sweetened drink with a meal significantly decreases fat utilization and diet-induced thermogenesis. And when the sugar-sweetened drink is paired with a protein-rich meal it further decreased fat utilization and diet-induced thermogenesis by more than 40%. These data highlight the impact consuming a sugar-sweetened drink can have on energy balance and fat utilization. One implication of the results is that the body’s reduced metabolic efficiency after drinking a sugar-sweetened beverage can lead to a greater tendency to make and store fat. These findings provide further insight into the potential role of sugar-sweetened drinks in the etiology of obesity.
Review Publications
Scherr, R.E., Laugero, K.D., Graham, D.J., Cunningham, B.T., Jahns, L.A., Lora, K.R., Reicks, M., Mobley, A.R. 2017. Innovative techniques for evaluating behavioral nutrition interventions. Advances in Nutrition. 8:113-25.
Jahns, L.A., Conrad, Z.S., Johnson, L., Scheett, A., Raatz, S.K. 2017. Diet quality is lower and energy intake higher on weekends compared to weekdays in midlife women: A one-year cohort study. Journal of the Academy of Nutrition and Dietetics. doi:10.1016/j.jand.2017.01.012.
Casperson, S.L., Johnson, L., Roemmich, J.N. 2017. The relative reinforcing value of sweet versus savory snack foods after consumption of sugar- or non-nutritive-sweetened beverages. Appetite. doi:10.1016/j.appet.2017.01.028.
Conrad, Z.S., Karlsen, M., Chui, K., Jahns, L.A. 2017. Diet quality on meatless days: National Health and Nutrition Examination Survey (NHANES), 2007-2012. Public Health Nutrition. doi:10.1017/S136898001700026X.
Conrad, Z.S., Johnson, L.K., Roemmich, J.N., Jaun, W., Jahns, L.A. 2017. Time trends and patterns of reported egg consumption in the U.S. by sociodemographic characteristics. Nutrients. 9(4):333.
Salvy, S., Feda, D.M., Epstein, L.H., Roemmich, J.N. 2016. Friends and social contexts as unshared environments: A discordant sibling analysis of obesity- and health-related behaviors in young adolescents. International Journal of Obesity. doi:10.1038/ijo.2016.213.
Flack, K.D., Johnson, L., Roemmich, J.N. 2017. Aerobic and resistance exercise reinforcement and discomfort tolerance predict meeting activity guidelines. Physiology and Behavior. 170:32-36.
Xie, L., Zhang, K., Rasmussen, D., Wang, J., Wu, D., Roemmich, J.N., Bundy, A.N., Johnson, W., Larson, K.J. 2017. Effects of prenatal low protein and postnatal high fat diets on visceral adipose tissue macrophage phenotypes and IL-6 expression in Sprague Dawley rat offspring. Journal of Nutrition. doi: 10.1371/journal.pone.0169581.
Salvy, S., Feda, D.M., Epstein, L.H., Roemmich, J.N. 2017. The social context moderates the relationships between neighborhood safety and adolescents’ physical activities. Preventive Medicine Reports. 6:355-360.
Raatz, S.K., Conrad, Z.S., Johnson, L., Picklo, M.J., Jahns, L.A. 2017. Relationship of the reported intakes of fat and fatty acids to body weight in US adults. Nutrients. doi:10.3390/nu9050438.
Kranz, S., Dodd, K.D., Juan, W.D., Johnson, L.K., Jahns, L.A. 2017. Whole grains contribute a small proportion of dietary fiber to the U.S. diet: National Health and Nutrition Examination Survey (NHANES) 2003-2010. Nutrients. doi:10.3390/nu9020153.
Jahns, L.A., Johnson, L.K., Scheet, A.J., Stote, K.S., Raatz, S.K., Subar, A.F., Tande, D. 2016. Measures of diet quality across calendar and holiday seasons among midlife women: A one-year longitudinal study using the automated self-administered 24-hour dietary recall. Journal of the Academy of Nutrition and Dietetics. 116(12):1961-1969. doi:10.1016/j.jand.2016.07.013.
Dekrey, E.E., Roemmich, J.N., Larson, K.J. 2016. Maternal low protein diet leads to placental angiogenic compensation via dysregulated M1/M2 macrophages and TNFa expression in Sprague-Dawley rats. Journal of Reproductive Immunology. 118:9-17.
Nguyen, L.M., Scherr, R.E., Dharmar, M., Ermakov, I.V., Gellerman, W., Jahns, L.A., Keen, C.L., Steinberg, F.M., Young, H.M., Zidenberg-Cherr, S. 2017. Using skin carotenoids to assess dietary changes in students after one academic year of participating in the shaping healthy choices program. Journal of Nutrition Education and Behavior. 49(1):73-78.e1.
Casperson, S.L., Hall, C.B., Roemmich, J.N. 2017. Postprandial energy metabolism and substrate oxidation in response to the inclusion of a sugar- or non-nutritive sweetened beverage with meals differing in protein content. Biomed Central (BMC) Nutrition. 3:49.
Casperson, S.L., Roemmich, J.N. 2017. Impact of dietary protein and gender on food reinforcement. Nutrients. doi:10.3390/nu9090957.
