Darcy Johannsen, PhD, RDAssistant Professor - Research
John S McIlhenny Skeletal Muscle Physiology
EDUCATIONSouth Dakota State University, Brookings, SD, B.S., 1996, Nutrition and Dietetics
Hurley Medical Center, Flint, MI, 1997, Dietetic Internship
South Dakota State University, Brookings, SD, M.S., 2001, Nutrition
Iowa State University, Ames, IA, Ph.D., 2006, Nutritional Sciences
RESEARCH INTERESTSDr. Johannsen’s research focuses on how dietary manipulations affect clinical outcomes including insulin sensitivity, fat deposition, and energy expenditure. In particular, she is interested in how calorie and macronutrient intake influence cellular energy flux and subsequently, lipid deposition and insulin signaling. Areas of active research include the response of skeletal muscle mitochondria to high fat overfeeding and the influence on weight gain and metabolism. Future projects will investigate whether high protein, low carbohydrate diets can reduce liver fat content and improve metabolic profile in elderly individuals and adults with abdominal obesity.
SELECTED PUBLICATIONSJohannsen DL, Johannsen NM, Specker BL. Influence of parent’s eating behaviors and child-feeding practices on children’s weight status. Obesity 14: 431-43 (2006).
Rubenbauer JR, Johannsen DL, Baier SM, Litchfield R, Flakoll PJ. The use of a hand-held calorimetry unit to estimate energy expenditure during different physiological conditions. J Parenter and Enteral Nutr 30: 246-50 (2006).
Johannsen DL, Redman LM, Ravussin E. The role of physical activity in maintaining a reduced weight. Current Atherosclerosis Reports 9: 463-71 (2007).
Johannsen DL, Welk GJ, Sharp RL, Flakoll PJ. Differences in daily energy expenditure in lean and obese women: The role of posture allocation. Obesity 16: 34-39 (2008).
Johannsen DL, DeLany JP, Frisard MI, Welsch MA, Rowley CK, Fang X, Jazwinski SM, Ravussin E. Physical activity in aging: comparison among young, aged, and nonagenarian individuals. J Appl Physiol 105: 495-501 (2008).
Johannsen DL and Ravussin E. Spontaneous physical activity: relationship between fidgeting and body weight control. Curr Opin Endocrinol Diabetes Obes 15: 409-15 (2008).
Baier S, Johannsen D, Abumrad N, Rathmacher JA, Nissen S, Flakoll P. Year-long changes in protein metabolism in elderly men and women supplemented with a nutrition cocktail of beta-hydroxy-beta-methylbutyrate (HMB), L-arginine, and L-lysine. J Parenter Enteral Nutr. 33: 71-82 (2009).
Johannsen DL, Calabro MA, Stewart J, Franke W, Rood JC, Welk GJ. Accuracy of armband monitors for measuring daily energy expenditure in healthy adults. Med Sci Sports Exerc. 42(11):2134-2140 (2010).
Johannsen DL and Ravussin E. The role of mitochondria in health and disease. Curr Opin Pharmacol 9: 780-86 (2009).
Johannsen DL and Ravussin E. Obesity in the elderly: is faulty metabolism to blame? Aging Health 6(2):159-167 (2010).
Johannsen DL and Ravussin E. Can increased muscle ROS scavenging keep older animals young and metabolically fit? Cell Metab. 12(6):557-558 (2010) (Commentary).
Johannsen DL, Conley KE, Bajpeyi S, Punyanitya M, Gallagher D, Zhang Z, Covington J, Smith SR, Ravussin E. Ectopic lipid accumulation and reduced glucose tolerance in elderly adults are accompanied by altered skeletal muscle mitochondrial activity. J Clin Endocrinol Metab. 97(1):242-250 (2012).
Tam CS, Sparks LM, Johannsen DL, Church TS, Ravussin E. Low macrophage accumulation in skeletal muscle of obese type 2 diabetics and elderly subjects. Obesity 20(7):1530-1533 (2012).
Johannsen DL*, Knuth ND*, Huizenga R, Rood JC, Ravussin E, Hall KD. Metabolic slowing with massive weight loss despite preservation of fat-free mass. J Clin Endocrinol Metab. 97(7):2489-96 (2012).
Johannsen DL, Galgani JE, Johannsen NM, Zhang Z, Covington J and Eric Ravussin. Effect of short-term thyroxine administration on energy metabolism and mitochondrial efficiency in humans. PLoS One 7(7):e40837(2012)
Peterson CM, Johannsen DL, Ravussin E. Skeletal muscle mitochondria and aging: A review. J Aging Res.194821. Epub 2012 Jul 19
Gupta AK, Ravussin E, Johannsen DL, Stull AJ, Cefalu WT and Johnson WD. Endothelial dysfunction: An early cardiovascular risk marker in asymptomatic obese individuals with prediabetes. Br J Med Med Res. 2012 May 30;2(3):413-423.