Obesity, and the health complications associated with this epidemic continues to negatively affect the lives of American young people.  In particular, the increased prevalence of obesity is accompanied by an increase in type 2 diabetes, which is now one of the most common chronic diseases among children and adolescents.  One of the primary obesity contributors includes the food-centric environment containing easy access to highly palatable, energy dense, but nutrient-poor foods which leads to overeating and weight gain - particularly in young people.  Thus, it is essential to develop successful strategies that target weight and glycemic control to reverse the obesity epidemic and prevent or delay serious health complications.

​Substantial evidence exists supporting the consumption of increased dietary protein to prevent and/or treat obesity through improvements in weight management and glycemic control.  The effectiveness of these diets may be due, in part, to modulations in energy metabolism, appetite, and energy intake.  Thus, my research group examines the effects of protein quantity, quality, and timing of consumption on the physiological (i.e., energy-sensing) and hedonic (i.e., reward-driven) signals that modulate appetite, satiety, and food motivation in overweight/obese young people.  More recently, we have begun to extend these findings to include key health outcomes such as weight management, glycemic control, and cardio-metabolic health.

Our primary nutrition emphasis areas attempt to answer the following questions:  1) Is there an optimal amount of protein (i.e., a protein threshold)/eating occasion required to achieve satiety and improve food intake regulation; 2) Does protein quality (animal vs. plant proteins) influence satiety and are there specific amino acids that serve as nutrient-triggers; and 3) Does increased dietary protein at breakfast lead to improved weight management through improved satiety, reduced food cravings, and improved glycemic control?  We have recently become interested in the connection between breakfast consumption, circadian rhythms, and sleep behavior.

To answer these questions we have developed and/or incorporate the following procedures within our human clinical studies:  repeated blood sampling of the gut-derived appetite and satiety hormones and plasma amino acid analyses; food-cue stimulated functional magnetic resonance imaging (fMRI) brain scans, iPod appetite apps, all-you-can-eat snack packouts, DXA, continuous glucose monitoring, actigraphy (with sleep assessments), post-prandial energy expenditure, etc.

​This body of research provides novel, relevant, and practical evidence supporting the consumption of increased, high quality protein, particularly at breakfast, as a key dietary strategy for improvements in appetite, satiety, glycemic control, and weight management in young people.  The knowledge gained from these studies will determine mechanisms by which a protein-rich breakfast may play a role in the treatment of obesity and prevention of type 2 diabetes in young people.

Liu Y, Tooze JA, Zhang Y, Leidy HJ, Bailey R, Wright B, Ma M, Stluka S, Remley DT, McCormack LA, Franzen-Castle L, Henne R, Mehrle D, Moore L, Eicher-Miller HA Breakfast consumption is positively associated with usual nutrient intakes among food pantry clients living in rural communities.  J Nutrition, 2019 Nov 9. pii: nxz258. doi: 10.1093/jn/nxz258. [Epub ahead of print]

Douglas SM, Byers AW, and Leidy HJ. Habitual breakfast patterns do not influence appetite and satiety responses to normal vs. high-protein breakfasts in overweight adolescents. Nutrients; 11; 1223; doi:  10.3390/nu11061223; 2019

Douglas SM and Leidy HJ.  Novel Methodological Considerations Regarding the Use of Visual Analog Scale (VAS) Appetite Questionnaires in Tightly Controlled Feeding Trials.  Curr Dev Nutr, https://doi.org/10.1093/cdn/nzz061; 2019

Gwin JA and Leidy HJ; Breakfast consumption augments appetite, eating behavior, and exploratory markers of sleep quality compared to skipping breakfast in healthy young adults; Curr Dev Nutr, Nov; 2(11), 2018

Sharafi M, Leidy, HJ, Wilson M, Alamdari N, Glynn EL.  Effect of a high-protein, high-fiber beverage preload on subjective appetite ratings and subsequent ad Libitum energy intake in overweight men and women: A randomized, double-blind placebo-controlled crossover study.  Curr Dev Nut, Jun 23; 2(6), 2018

Bolster D, Rahn M, Kamil A, Toth L, Leidy HJ, Blaze M, Nunez M, Guo E, Wang J, Harkness L. Consuming lower-protein nutrition bars with added leucine elicits postprandial changes in appetite sensations in healthy women.  J Nutrition, Apr 20   https://doi.org/10.1093/jn/nxy023, 2018

Gwin JA and Leidy HJ. A review of the evidence surrounding the effects of breakfast consumption on mechanisms of weight management; Review; Advances in Nutrition, Sep 10. doi: 10.1093/advances/nmy047; 2018

Gwin JA, Maki KC, Alwattar AY, Leidy HJ.  Examination of protein quantity and protein distribution across the day on ad libitum carbohydrate and fat intake in overweight women. Curr Dev Nutr; Oct; 1(12):e001933, 2017

Gwin JA, Maki KC, Leidy HJ.  Increased protein consumption during the day from an energy-restricted diet augments satiety but does not reduce daily fat or carbohydrate intake on a free-living test day in overweight women.  J Nutrition; Dec; 147(12); 2338-2346; 2017

Leidy HJ, Gwin JA, Roenfeldt CA, Zino AZ, Shafer RS; Evaluating the intervention-based evidence surrounding the causal role of breakfast on markers of weight management, with specific focus on breakfast composition and size; Advances in Nutrition, May; 7; 563S-575S; 2016

Phillips S, Chevalier S, Leidy HJ; Protein ‘requirements’ beyond the RDA:  implications for optimizing health; Applied Physiology, Nutrition, and Metabolism, May; 41(5); 565-72; 2016

Dhillon J, Craig BA, Leidy HJ, Amankwaah AF, Anguah KO, Jacobs AG, Jones BL, Jones J, Keeler CL, Keller CE, McCrory MA, Rivera RL, Slebodnik M, Mattes RD, Tucker RM; The effects of increased protein intake on fullness: a meta-analysis and its limitations. J Acad Nutr Diet; Jun;116(6):968-83; 2016

Leidy, HJ, Clifton PM, Astrup A, Wycherley TP, Westerterp-Plantenga MS, Luscombe-Marsh ND, Woods SC, Mattes RD.  The Role of Protein in Weight Loss and Maintenance; Symposium Proceedings; American Journal of Clinical Nutrition; Jun; 101 (6):  1320S-1329S, 2015

Leidy HJ, Hoertel JA, Douglas SM, Higgins KA, Shafer RS  A high-protein breakfast prevents body fat gain, through reductions in daily intake and hunger, in “Breakfast Skipping’ adolescents; Obesity; Sept; 23(9):  1761-4; 2015

Bauer LB, Reynolds LJ, Douglas SM, Kearney ML, Hoertel HA, Shafer RS, Thyfault JP, Leidy HJ A pilot study examining the effects of consuming a high-protein vs. normal-protein breakfast on free-living glycemic control in overweight/obese ‘breakfast skipping’ adolescents; International Journal of Obesity; Sept; 39(9):  1421-4; 2015

Leidy HJ, Todd CB, Zino AZ, Immel JE, Mukherjea R, Shafer RS, Ortinau LC, Braun M Consuming high-protein soy snacks affects appetite control, satiety, and diet quality in young people and influences select aspects of mood and cognition; Journal of Nutrition, Jul; 145(7):  1614-22; 2015

Douglas SM, Lasley TR, HJ Leidy  Consuming beef vs. soy protein has little effect on appetite, satiety, and food intake in healthy adults; Journal of Nutrition; May; 145(5):  1010-6; 2015

Alwattar AY, Thyfault JP, Leidy HJ.  The effect of breakfast type and frequency of consumption on glycemic response in overweight/obese late adolescent girls. European Journal of Clinical Nutrition; Aug; 69(8):  885-90; 2015

Rains TM, Leidy HJ, Sanoshy, KR, Lawless A, Maki KC  A Randomized, Controlled, Crossover Trial to Assess the Acute Appetitive and Metabolic Effects of Sausage and Egg-based Convenience Breakfast Meals in Overweight Premenopausal Women. Nutrition Journal; Feb; 14(17); 2015

Park YM, Heden T, Liu Y, Nyhoff L, Thyfault JP, Leidy HJ, and Kanaley J. A high-protein breakfast induces greater insulin and glucose-dependent insulinotripic peptide responses to a subsequent lunch meal in individuals with Type 2 diabetes; Journal of Nutrition; Mar; 145 (3), 452-458, 2015

Reynolds LJ, Credeur DP, Holwerda SW, Leidy HJ, Fadel PJ, and Thyfault JP.  Acute inactivity impairs glycemic control but not blood flow to glucose ingestion.  Medicine and Science in Sports and Exercise; May; 47(5), 1087-94, 2015

Hoertel HA, Will MJ, and Leidy HJ.  A randomized crossover, pilot study examining the effects of a normal protein vs. high protein breakfast on food cravings and reward signals in overweight/obese "breakfast skipping," late-adolescent girls.  Nutrition Journal; Aug; 13(80); 2014

Oberlin DJ, Mikus CR, Kearney ML, Hinton PS, Manrique C, Leidy HJ, Kanaley JA, Rector RS, Thyfault JP.  One bout of exercise alters free-living postprandial glycemia in Type 2 Diabetes.  Medicine and Science in Sports and Exercise; 46(2):  232-238; 2014

Leidy, HJ. Increased dietary protein as a dietary strategy to prevent and/or treat obesity.  Invited Review; Missouri Medical Review;  Jan-Feb; 111 (1):  54-8; 2014

Paddon-Jones, D and Leidy HJ. Protein and muscle in older persons; Invited Review. Current Opinion in Clinical Nutrition and Metabolic Care; 17:  5-11; 2014

Leidy, HJ.  The Benefits of Breakfast Consumption to Combat Obesity and Diabetes in Young People. Invited Review;  American Journal of Lifestyle Medicine; 7(2); 98-104; 2013 

Tang M, Leidy HJ, Campbell WW. Regional, but not total, body composition changes in overweight and obese adults consuming a higher-protein, energy-restricted diet are sex specific.  Nutrition Research; Aug; 33(8): 629-35; 2013

Leidy HJ, Ortinau LC, Douglas SM, Hoertel HA.  Beneficial effects of a protein-rich breakfast on the appetitive, hormonal, and neural signals controlling energy intake regulation to combat obesity in late-adolescent females.  American Journal of Clinical Nutrition; 97(4):  677-88; 2013

 Tang M, Armstrong CLH, Leidy HJ, Campbell WW.  Normal vs. high-protein weight loss diets in men:  effects on body composition and indices of metabolic syndrome.  Obesity, Mar; 21(3): E204-10; 2013

Douglas SM, Ortinau LC, Hoertel HA, Leidy HJ.  Low, moderate, or high protein yogurt snacks on appetite control and subsequent eating in healthy women.  Appetite; Jan; 60; 117-122; 2013

Leidy, HJ. Evidence supporting a diet rich in protein to improve appetite control, satiety, and weight management across the lifespan.  Proceedings Paper of the 65th Annual Reciprocal Meat Conference; American Meat Association; 2012

Scheid JL, De Souza MJ, Leidy HJ, Williams.  Ghrelin but not Peptide YY is related to change in body weight and energy availability. Medicine and Science in Sports and Exercise; Nov; 43(11):  2063-2071; 2011

Leidy HJ, Lepping RJ, Savage CR, Harris CT.  Neural responses to visual food stimuli after normal vs. higher protein breakfast in breakfast-skipping teens-a pilot fMRI study.  Obesity; Oct; 19(10):  2019-2025; 2011

Apolzan JW, Leidy HJ, Mattes RD, Campbell WW.  Effects of food form on food intake and postprandial appetite sensations, glucose and endocrine responses, and energy expenditure in resistance trained vs. sedentary older adults  British Journal of Nutrition; Oct; 106(7):  1107-1116; 2011

Leidy HJ, Bales-Voelker LI, Harris CT.  A protein-rich beverage consumed as a breakfast meal leads to weaker appetitive and dietary responses v. a protein-rich solid breakfast meal in adolescents.  British Journal Obesity; Jul; 106(1):  37-41; 2011

Conley TB, Apolzan JA, Leidy HJ, Greaves KA, Lim E, and Campbell WW.  Effect of food form on postprandial plasma amino acid concentrations in older adults.  British Journal of Nutrition; 106(2):  203-207; 2011

Leidy HJ, Tang M, Armstrong CLH, Martin CB, and Campbell WW.  The effects of consuming frequent, higher protein meals on appetite and satiety during weight loss in overweight/obese men.  Obesity; 19 (4):  818-824; 2011

Laan DJ, Leidy HJ, Lim E, Campbell WW.  Effects and reproducibility of aerobic and resistance exercise on appetite and energy intake in young physically active adults.   Applied Physiology, Nutrition, and Metabolism; 35:  842-847; 2010

Leidy HJ, Armstrong CLH, Tang M, Mattes RD, and Campbell WW.  The influence of higher protein intake and greater eating frequency on appetite control in overweight and obese men.  Obesity;  Sep; 18(9):  1725-1732; 2010

Leidy HJ & Racki EM.  The addition of a protein-rich breakfast and its effects on acute appetite control and food intake in `breakfast-skipping' adolescents.  International Journal of Obesity;  Jul; 34(7):  1125-1133; 2010

Leidy HJ, Apolzan JW, Mattes RD, and Campbell WW.  Food form and portion size affect postprandial appetite sensations and hormonal responses in healthy, nonobese, older adults.  Obesity; Feb; 18(2):  293-299; 2010

Leidy HJ & Campbell WW.  Symposium:  Eating frequency, snacking, and breakfast skipping: do they matter for energy regulation?  The effect of eating frequency on appetite control and food intake:  brief synopsis of controlled feeding studies.  Journal of Nutrition ;141(1):  154-157; 2010

Leidy HJ, Bossingham MJ, Carnell NS, Mattes RD, and Campbell WW.  Increased dietary protein consumed at breakfast leads to an immediate and sustained feeling of fullness during energy restriction compared to other meal times.  British Journal of Nutrition; 101:798-803; 2009

Leidy HJ, Carnell NS, Mattes RD, Campbell WW.  Higher protein intake preserves lean mass & satiety with weight loss in pre-obese & obese women.  Obesity; 15:421-429; 2007

Leidy HJ, Mattes RD, Campbell WW.  Effects of acute & chronic protein intake on metabolism, appetite & ghrelin during weight loss. Obesity;  15:1215-25; 2007

Tieken SM, Leidy HJ, Stull AJ, Mattes RD, Schuster RA, Campbell WW.  Effects of solid vs. liquid meal-replacement products of similar energy content on hunger, satiety, and appetite-regulating hormones in older adults.  Hormone and Metabolic Research;  39:389-94; 2007

Leidy HJ, Dougherty KA, Frye BR, Duke KM, and Williams NI.  Twenty-four-hour ghrelin is elevated after calorie restriction and exercise training in non-obese women.  Obesity;  15:446-455; 2007

Campbell WW and Leidy HJ. Dietary protein and resistance training effects on muscle and body composition in older persons.  Review.  Journal of the American College of Nutrition; 26:  696S-703S; 2007

Leidy HJ and Williams NI. Meal energy content is related to features of meal-related ghrelin profiles across a typical day of eating in non-obese premenopausal women. Hormone and Metabolic Research;  38:317-322; 2006

Leidy HJ, Gardner JK, Frye BR,  Snook ML, Schuchert MK, Richard EL, Williams NI.  Circulating Ghrelin is Sensitive to Changes in Body Weight during a Diet and Exercise Program in Normal Weight Young Women.  Journal of Clinical Endocrinology and Metabolism:  Special Thematic Issue; 89:2659-2664; 2004

https://www.conagranutrition.com/webinars/exploring-benefits-increased-protein-consumption

https://drive.google.com/file/d/1_NOPdAfevlU79kMysJekbnReIB3y0VbZ/view

https://www.youtube.com/watch?v=x2phzDFyeJc&t=1680s