Human Energy and Body Weight Regulation Core

National Institute Of Diabetes And Digestive And Kidney Diseases

Investigators

Linked publications, trials & patents

Abstract

The Core continues to be a part of the Metabolic Clinical Research Unit (MCRU), which was established at NIH in 2007 under the first NIH Strategic Plan for Obesity Research (http://www.obesityresearch.nih.gov/strategic-plan). It is design to conduct research to identify potential causes and evaluate treatments of obesity. Currently 1/3 of the adult US population is obese and another 1/3 are overweight. Obesity is a major cause of diabetes, cardiovascular disease, and some cancers, yet our understanding of obesity physiology is rudimentary. The obesity epidemic has continued unabatedthe need for rigorous and properly controlled metabolic research is even more important. At the NIH, much of the Intramural clinical research is conducted on the MCRU that consists of the 5SW-N (inpatient) unit, 5SW-S (day hospital), and 7SW-S whole room calorimetry suites, which includes a special room with a DXA body composition scanner, and Bod Pod, an exercise testing room, portable activity measurements, and highlighted by the three customized whole-room indirect calorimeters (respiratory chambers) as the key components of the Core function. Due to the COVID-19 global pandemic that significantly impacted the MCRU, our census and services rendered were negatively impacted: energy expenditure by respiratory chambers (48), resting energy expenditure by metabolic carts (66), graded-exercise test (0 due to aerosolizing risks), experimental food behavior tests (15), and body composition (60 DXA). The Core continues to support 21 clinical protocols and protocols from 14 different IC's of the NIH. Research highlights in FY21: 1. We are supporting a major NIH Clinical Center study on the chronic adaptation and response to exercise trial (COVID-CARE https://clinicaltrials.gov/ct2/show/NCT04595773) initialized in Oct 2020. The primary objective of the trial is to study if participation in a rehabilitation exercise program can help people recovering from COVID-19. Eventually 80 adults ages 18-80 with confirmed SARS-CoV2 infection with clinical symptoms will be studied. This randomized controlled trial will determine whether aerobic exercise training has a beneficial effect on physical function, health-related quality of life, free-living physical activity and sleep quality among survivors of COVID-19 (our primary responsibility). Participants will be randomized to either an aerobic exercise training and education (AET+) group or a control education only group (CON) for 10 weeks. Assessments for physical function, self-reported health outcomes for quality of life (QOL), free-living physical activity and sleep quality will be measured at baseline and following the 10-week intervention period. Participants in the CON group will then crossover and perform AET after the 10-week follow-up visit. All participants will be monitored for one year to capture free-living physical activity, sleep quality and health-related QOL outcomes over time. It is hypothesized that following 10 weeks, physical function, health-related QOL, free-living physical activity and sleep quality will show greater improvement with AET+. To date, we have enrolled 18 participants, completed 5, and following 12. We have another COVID-19 related to chronic fatigue study designed and planned to start in early FY22. 2. We published several papers in FY 21 on the changes of sleep and physical activity patterns and their associations with mental and physical health parameters in Icelandic adolescents at 15 and 17 years of age, all stemming from a long-term collaboration project with a team of researchers at the University of Iceland. We found an alarming percentage of these adolescents did not have sufficient sleep during most school nights (averaging about 6 hours/night), which were associated with poorer school performances and memory and attention. Together, these findings support the idea that both sufficient amount of sleep, physical activity, and perhaps regular schedules are important for the health of adolescents. 3. We supported two important studies lead by Dr. Kevin Hall. In a paper published in Cell Metabolism, we investigated whether ultra-processed foods affect energy intake in 20 weight-stable adults. We randomized them to either ultra-processed or unprocessed diets for 2 weeks immediately followed by the alternate diet for 2 weeks, all matched for presented calories, energy density, macronutrients, sugar, sodium, and fiber. Energy intake was greater during the ultra-processed diet (508 106 kcal/day; p = 0.0001), with increased consumption of carbohydrate (280 54 kcal/day; p < 0.0001) and fat (230 53 kcal/day; p = 0.0004). Thus, limiting consumption of ultra-processed foods may be an effective strategy for obesity prevention and treatment. In another paper published in Nature Medicine, we randomized healthy overweight subjects to consume ad libitum either a minimally processed, plant-based, low-fat diet (10.3% fat, 75.2% carbohydrate) with high glycemic load (85g1,000kcal1) or a minimally processed, animal-based, ketogenic, low-carbohydrate diet (75.8% fat, 10.0% carbohydrate) with low glycemic load (6g/1,000kcal) for 2 weeks followed immediately by the alternate diet for 2 weeks. We found that the low-fat diet led to 68973kcal/day less energy intake than the low-carbohydrate diet over 2 weeks (p<0.0001) and 54468kcal/day less over the final week (p<0.0001). Thus, we concluded that the predictions of the carbohydrateinsulin model were inconsistent with our observations. 4. We installed a 3D laser-guided body surface scanner to our body composition lab during FY21. The goal of using this non-invasive scanner is to accurately measure body surface area (BSA) in human subjects rather than relying on simple prediction models using weight, height, and sex parameters which were developed over 60-70 years ago. We are planning a new natural history protocol to examine the agreement between measured BSA and BSA estimated by previously established prediction equations in both healthy children and adults, those with recent changes in weight, and those with various forms of disease. We then plan to compare laser measured BSA with body composition and energy expenditure parameters.