Dr Julia Zakrzewski-Fruer

Senior Lecturer in Health, Nutrition and Exercise

Julia Zakrzewski-Fruer

After gaining an undergraduate degree in Sport and Exercise Science from Loughborough University (2004-2007), I completed an MSc by Research at the University of Gloucestershire (2007-2008) and a PhD at Loughborough University (2008-2011).

My PhD focused on the effect of manipulations in exercise and breakfast on metabolism in overweight and non-overweight young people (children and adolescents).

I then worked as a Research Officer at the University of Bath, where I managed the UK site for the International Study of Childhood Obesity, Lifestyle and the Environment (ISCOLE). Subsequently, I was appointed as a Lecturer at the University of Bedfordshire in 2013 to research and teach in the areas of exercise, nutrition and health.

My primary research interests focus on how manipulations in exercise and nutrition can improve health and prevent obesity in young people (children and adolescents). This research has included studies on exercise metabolism, breakfast consumption, glycaemic index, glycaemic control, insulin insensitivity and energy balance.

I am currently working on numerous projects investigating the effect of breakfast consumption on components of energy balance and cardiometabolic health in children and adolescents.

I also collaborate with an international team of experts on ISCOLE to examine associations between breakfast consumption, physical activity and childhood obesity in children from 12 countries across the world.


  • PhD, Exercise, Nutrition and Health – Loughborough University
  • MSc by Research – Exercise Physiology in Overweight Children - University of Gloucestershire
  • BSc (Hons), Sport and Exercise Science – Loughborough University

Teaching Expertise

  • Physical activity, nutrition and health
  • Exercise physiology
  • Undergraduate and postgraduate courses
  • Dissertation supervision

Research Interests

  • Physical activity and cardiometabolic health in children and adolescents
  • Glycaemic control and insulin sensitivity
  • Breakfast consumption versus omission
  • Exercise metabolism and substrate oxidation
  • Energy balance, exercise and appetite
  • Childhood obesity

Research Projects

  • How does breakfast consumption versus omission affect free-living physical activity and cardiometabolic health in adolescents?
  • Measuring glycaemic control and insulin sensitivity in adolescents – impact of exercise and nutrition manipulations
  • Exercise and appetite


  • Zakrzewski-Fruer JK, Horsfall RN, Cottrill DC, Hough J. Acute exposure to a hot ambient temperature reduces energy intake but does not affect gut hormones in men during rest. Br J Nutr. 2020 22;1-25. doi: 10.1017/S0007114520002792.
  • Hough J, Esh C, Mackie P, Stensel DJ, Zakrzewski-Fruer JK. Daily running exercise may induce incomplete energy intake compensation: a 7-day crossover trial. Appl Physiol Nutr Metab. 2020;45(4):446-449.
  • Maylor BD, Zakrzewski-Fruer JK, Stensel DJ, Orton CJ, Bailey DP. Effects of Frequency and Duration of Interrupting Sitting on Cardiometabolic Risk Markers. Int J Sports Med. 2019;40(13):818-824.
  • Zakrzewski-Fruer JK, Gillison FB, Katzmarzyk PT, Mire EF, Broyles ST, Champagne CM, Chaput JP, Denstel KD, Fogelholm M, Hu G, Lambert EV, Maher C, Maia J, Olds T, Onywera V, Sarmiento OL, Tremblay MS, Tudor-Locke C, Standage M; ISCOLE Research Group. Association between breakfast frequency and physical activity and sedentary time: a cross-sectional study in children from 12 countries. BMC Public Health. 2019;19(1):222.
  • Bailey DP, Orton CJ, Maylor BD, Zakrzewski-Fruer JK. Cardiometabolic Response to a single high-intensity interval exercise session versus breaking up sedentary time with fragmented high-intensity interval exercise. Int J Sports Med. 2019;40(3):165-170.
  • Maylor BD, Zakrzewski-Fruer JK, Orton CJ, Bailey DP. Beneficial postprandial lipaemic effects of interrupting sedentary time with high-intensity physical activity versus a continuous moderate-intensity physical activity bout: A randomised crossover trial. J Sci Med Sport. 2018;21(12):1250-1255.
  • Maylor BD, Edwardson CL, Zakrzewski-Fruer JK, Champion RB, Bailey DP. Efficacy of a multi-component intervention to reduce workplace sitting time in office workers: a cluster randomized controlled trial. J Occup Environ Med. 2018;60(9):787-795.
  • Tolfrey K, Zakrzewski-Fruer JK, Thackray AE. Metabolism and Exercise During Youth-The Year That Was 2017. Pediatr Exerc Sci. 2018;30(1):38-41
  • Zakrzewski-Fruer JK, Wells EK, Crawford NSG, Afeef SMO, Tolfrey K. Physical activity duration but not energy expenditure differs between daily compared with intermittent breakfast consumption in adolescent girls: a randomized crossover trial. J Nutr. 2018; 148(2):236–244.
  • Zakrzewski-Fruer JK, Plekhanova T, Mandila D, Lekatis Y, Tolfrey K. Effect of breakfast omission and consumption on energy intake and physical activity in adolescent girls: a randomised controlled trial. Br J Nutr. 2017; 118(5):392-400.
  • Gillison F, Standage M, Cumming S, Zakrzewski-Fruer J, Rouse P, Katzmarzyk PT. Does parental support moderate the effect of children’s motivation and self-efficacy on physical activity and sedentary behaviour? Psychol Sport Exerc. 2017;32:153-161.
  • Bailey DP, Maylor BD, Orton CJ, Zakrzewski-Fruer JK. Effects of breaking up prolonged sitting following low and high glycaemic index breakfast consumption on glucose and insulin concentrations. Eur J Appl Physiol. 2017;117(7):1299-1307.
  • Tolfrey K, Zakrzewski-Fruer JK, Smallcombe J. Metabolism and exercise during youth. Pediatr Exerc Sci. 2017;29(1):39-44.
  • Zakrzewski JK, Tolfrey K. Carbohydrate needs of the young athlete. In: Sport Nutrition Needs for Child and Adolescent Athletes (edited by C. Kirksick). Boca Raton, FL, USA: Taylor & Francis: CRC Press; 2016, pp 35-58.
  • Zakrzewski JK, Gillison FB, Cumming S, Church TS, Katzmarzyk PT, Broyles ST, Champagne CM, Chaput JP, Dentro KN, Fogelholm M, Hu G, Kuriyan R, Kurpad AV, Lambert EV, Maher C, Maia J, Matsudo V, Mire EF, Olds T, Onywera V, Sarmiento OL, Tremblay MS,Tudor-Locke C, Zhao P, Standage M for the ISCOLE Research Group. Associations between breakfast frequency and adiposity indicators in children from 12 countries. Int J Obes. 2015;5:S80-S88.
  • Potter CR, Zakrzewski JK, Draper SB, Unnithan VB. The oxygen uptake kinetic response to moderate intensity exercise in overweight and non-overweight children. Int J Obes (Lond). 2013;37(1):101-6.
  • Tolfrey K, Zakrzewski JK. Invited review: Breakfast, glycaemic index and health in young people. Journal of Sport and Health Science. 2012;1(3):149-159.
  • Zakrzewski JK, Tolfrey K. Acute effect of Fatmax exercise on the metabolism in overweight and non-overweight girls. Med Sci Sports Exerc. 2012;44(9):1698-705.
  • Tolfrey K, Cooper SB, Zakrzewski JK, Nevill ME. Breakfast, metabolism, health and cognitive function. In: Reviews in Pediatric Exercise Science (edited by M. Duncan). New York: Nova Publishers Inc; 2012.
  • Zakrzewski JK, Stevenson EJ, Tolfrey K. Effect of breakfast glycaemic index on metabolic responses during rest and exercise in overweight and non-overweight adolescent girls. Eur J Clin Nutr. 2012;66(4):436-42.
  • Zakrzewski JK, Tolfrey K. Comparison of fat oxidation over a range of intensities during treadmill and cycling exercise in children. Eur J Appl Physiol. 2012;112(1):163-71.
  • Zakrzewski JK, Tolfrey K. Exercise protocols to estimate Fatmax and maximal fat oxidation in children. Pediatr Exerc Sci. 2011;23(1):122-35.
  • Zakrzewski JK, Tolfrey K. Fatmax in children and adolescents: A review. Eur J of Sport Sci. 2011;11(1):1-18.

Selected Awards and Professional Activities

Funding Awards

  • British Nutrition Foundation Pump Priming Awards (2018), Jones R and Zakrzewski-Fruer JK, ‘Acute impact of breakfast consumption and omission on glycaemia and insulinaemia in adolescent girls’. £4796 awarded. (Co-applicant).
  • Nutrition Society Summer Studentships (2018), Zakrzewski-Fruer JK, ‘The effects of breakfast consumption and breakfast omission on free-living physical activity energy expenditure and energy intake in adolescent girls classified as habitual breakfast skippers’. £2500 awarded. (Supervisor).
  • Society for Endocrinology Summer Studentships Projects (2016), Zakrzewski-Fruer JK, 'Interaction between environmental temperature and appetite regulation'. £2850 awarded. (Supervisor).
  • British Academy/Leverhulme Small Research Grants (2015-2017), Zakrzewski-Fruer JK and Tolfrey K, 'Interaction of breakfast consumption with daily energy expenditure in adolescent girls'. £9990 awarded. (Principal Investigator).
  • University of Bedfordshire Teaching and Learning Projects (2014-2015), Zakrzewski-Fruer JK and Bailey D, ‘Utilisation of dietary analysis software to develop an authentic problem-based learning environment to enhance student learning'. £2838 awarded. (Principal Investigator).
  • Tanita Healthy Weight Community Trust Grant (2011-2012), Tolfrey K and Zakrzewski-Fruer JK, ‘Effect of exercise energy expenditure on subsequent energy Intake in overweight and non-overweight children'. £8400 awarded. (Co-applicant).
  • Tanita Healthy Weight Community Trust Grant (2009-2010), Tolfrey K and Zakrzewski-Fruer JK, ‘Effect of breakfast glycaemic index on fat oxidation during subsequent low to moderate exercise’. £7000 awarded. (Co-applicant).

External Roles

  • Collaborator on the International Study of Childhood Obesity, Lifestyle and the Environment (ISCOLE), Pennington Biomedical Research Center, Louisiana, US.

Postgraduate Research Students

If you have funding to complete a PhD studentship or MSc by Research, I would welcome applications from anyone interested in the following areas of research:

  • How does breakfast consumption versus omission affect physical activity and cardiometabolic health outcomes (e.g., glycaemic control) in children and adolescents?
  • Exercise substrate metabolism in children and adolescents (e.g., maximal fat oxidation and Fatmax)
  • Paediatric overweight and obesity, glycaemic control and insulin sensitivity

Contact Details

E: julia.fruer@beds.ac.uk
T: +44 (0)1234 793410 (ext. 4410)


School of Sport Science and Physical Activity
Faculty of Education and Sport
Bedford campus
Polhill Avenue
MK41 9EA

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