Dr Alex Johnstone - Appetite across the lifecourse
Research Focus
Scottish Government funded work
A major goal in the battle with obesity in the general population is to develop strategies that produce a sustainable weight loss with a dietary and/or behavioural intervention. Increasing attention is being focused on diet composition in both weight control and metabolic health outcomes.
Sustainable food reformulation for enhanced satiety - Protein, fat and carbohydrate not only have different energy densities (fat has more than double the energy density per gram of protein or carbohydrate), but also have different effects on satiety, in the order protein>carbohydrate>fat. As a consequence, the combination in dietary fat of high energy density and low satiety may lead to over-consumption of calories, whereas diets with a higher protein content can enhance satiety and lead to weight loss. Elevated dietary protein, indisputably the most satiating macronutrient, reduces energy intake and generates weight loss. The potential benefit of reformulating food to reduce energy dense (fat) content whilst simultaneously building in enhanced satiety properties is clear, provided this dual benefit can be achieved with a sustainable formulation. The sustainability and affordability of the potential dietary reformulation will be a key consideration in order to generate effective options for the general population.
EU Funded Projects
NeuroFAST is a project funded by the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement n° 245009. This project examines the Integrated Neurobiology of Food Intake, Addiction and Stress
This multidisciplinary project will explore the neurobiology of addiction and eating behaviour and the complex socio-psychological forces that can lead to its dysregulation. These forces include dietary components (e.g. highly palatable foods and alcohol), some of which may have addictive properties, but also cultural and social pressures and cognitive-affective factors (perceived stress and stress regulation, anxiety and depression), and family-genetic influences on these. The project will provide new data from human studies that is needed to inform health policy initiatives, underpinned by mechanistic research to establish a solid scientific basis for this advice.
Full4health is a project funded by the European Union Seventh Framework Programme (FP7/2011-2016) under grant agreement n° 266408
This project will examine relationships with food and satiety signalling in across the age groups, from children to the elderly, with physiological and psychological measures related to and influencing food choice.
Satin – is a project funded by the European Union Seventh Framework Programme (FP7/2011-2016) under grant agreement n° 289800 to examine Satiety Innovation. This project will examine novel food ingredients on appetite control, with links with the food industry.
Communications
Alex has produced two briefing notes for Marks & Spencer on the Simply Fuller Longer range diet trial.
Briefing Note 1 pdf
Briefing Note 2 pdf
Scotland: The Land of Food and Drink.
Alex comments on the role of scientists from ‘Farm to Fork’ approach to food.
Alex participated in a joint symposium with Marks and Spencer at the Nutrition Society summer meeting pdf
Alex recently won the staff prize in the Blue Skies competition view pdf
Marks & Spencers have recently launched a new range of calorie controlled meals based on Alex’s published research on protein-enriched diets and the impact on satiety. Find out more here…..and read the press release here.
Policy Documents
Alex is an author on a recently commissioned report for the World Wildlife Fund on sustainability of current and future healthy eating diets. Download a pdf of the document here
Research Grants
NEUROFAST - NeuroFAST is a project funded by the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement n° 245009.
Full4Health – Full4Health is a project funded by the European Union Seventh Framework Programme (FP7/2011-2016) under grant agreement n° 266408.
Policy Briefings
Latest Publications
Walker AW, Ince J, Duncan SH, Webster LM, Holtrop G, Ze X, Brown D, Stares MD, Scott P, Bergerat A, Louis P, McIntosh F, Johnstone AM, Lobley GE, Parkhill J, Flint HJ. Dominant and diet-responsive groups of bacteria within the human colonic microbiota.. ISME J. 2011 Feb;5(2):220-30.
Siervo M, Faber P, Gibney ER, Lobley GE, Elia M, Stubbs RJ, Johnstone AM. Use of the cellular model of body composition to describe changes in body water compartments after total fasting, very low calorie diet and low calorie diet in obese men .Int J Obes (Lond). 2010 May;34(5):908-18.
Fyfe, C.L., Stewart, J., Murison, S.D., Jackson, D.M., Rance, K., Speakman, J.R., Horgan, G.W., Johnstone, A.M. Evaluating energy intake measurement in free-living subjects: when to record and for how long? Public Health Nutrition, 13 (2) February 2010 pp. 172-180
Johnstone AM, Horgan GW, Murison SD, Bremner DM, Lobley GE. Effects of a high-protein ketogenic diet on hunger, appetite, and weight loss in obese men feeding ad libitum. Am J Clin Nutr. 2008 Jan;87(1):44-55.
Johnstone, A.M. High-protein diets for appetite control and weight loss - the 'holy grail' of dieting? British Journal of Nutrition, 101 (12) June 2009 pp. 1729-1730
Gratz, S., Duncan, S.H., Richardson, A.J., Johnstone, A.M., Lobley, G.E., Flint, H.J., Wallace, R.J. High Protein Diets Impact on Microbial Metabolites and Toxicity in the Human Large Intestine. Microbial Ecology, 57 (3) April 2009 pp. 572-573.
Whybrow, S., Hughes, D.A., Ritz, P., Johnstone, A.M., Horgan, G.W., King, N., Blundell, J.E., Stubbs, R.J. The effect of an incremental increase in exercise on appetite, eating behaviour and energy balance in lean men and women feeding ad libitum. British Journal of Nutrition, 100 (5), November 2008 pp. 1109-1115
Speakman, J.R., Rance, K.A., Johnstone, A.M. Polymorphisms of the FTO Gene Are Associated With Variation in Energy Intake, but not Energy Expenditure. Obesity, 16 (8) August 2008. pp. 1961-1965.