Dr Alex Johnstone

Dr_Alex_Johnstone

Dr Alex Johnstone

Appetite across the lifecourse

A major goal in the battle against obesity in Scotland is to develop strategies that result in weight loss which can be sustained. This may be achieved with either a change in diet or a change in behaviour.

Increasing attention is now being focused on how the composition of the diet can affect weight control and I am interested how protein, from both plants and animals, can signal that you 'feel full'. I am currently running human volunteer studies to assess the impact of diets on the body and the mind and to investigate how different meals and drinks affect our appetite and health and wellbeing.

The research that we are doing can be used in the food industry to develop new products as well as helping to inform policymakers and health practitioners.


View Alex speaking about her recent REF2015 impact case study . Marks & Spencer (M&S) plc developed the Fuller Longer food range with expert input from University scientists. Dr Alexandra Johnstone, based at the Rowett Institute of Nutrition and Health, led this food industry collaboration.


Alex is the Lead for a free online course: Health and Nutrition MOOC


FHIS Science Bytes - Dr. Alex Johnstone video

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.

Research team


Dr Madalina Neacsu
- Research Fellow
Claire Fyfe
– Research Assistant

William Buosi
– PhD Student

Health impacts of sustainable ingredient selection in the food and drink industry

The Scottish food and drink industry faces many challenges, but one of the main concerns relates to food security. Climate change, increased fuel costs, and changing demographics all add to this uncertainty. However, the industry still needs to be able to provide affordable, acceptable and nutritious food. This programme is examining how well Scottish sourced plant proteins can contribute to the human diet in terms of nutritional value and physiological effect. The focus of this work is on replacing or augmenting traditional sources of protein in normal, healthy, balanced diets read more.


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.

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.


  • López-Nicolás, R., Marzorati, M., Scarabottolo, L., Halford, JCG., Johnstone, AM., Frontela-Saseta, C., Sanmartín, AM., Ros-Berruezo, G. & Harrold, JA. (2016). 'Satiety Innovations: Food Products to Assist Consumers with Weight Loss, Evidence on the Role of Satiety in Healthy Eating: Overview and In Vitro Approximation'. Current Obesity Reports, vol 5, no. 1, pp. 97-105.
    [Online] DOI: 10.1007/s13679-016-0196-9
  • Mercer, JG., Johnstone, A. & Halford, JCG. (2015). 'Approaches to influencing food choice across the age groups: from children to the elderly'. Proceedings of the Nutrition Society, vol 74, no. 02, pp. 149-157.
    [Online] DOI: 10.1017/S0029665114001712
  • Lobley, G., Holtrop, G., Horgan, G., Bremner, DM., Fyfe, CL. & Johnstone, A. (2015). 'Responses in gut hormones and hunger to diets with either high protein or a mixture of protein plus free amino acids supplied under weight-loss conditions'. British Journal of Nutrition, vol 113, no. 8, pp. 1254-1270.
    [Online] DOI: 10.1017/S0007114515000069
  • Siervo, M., Faber, P., Lara, J., Gibney, ER., Milne, E., Ritz, P., Lobley, GE., Elia, M., Stubbs, RJ. & Johnstone, AM. (2015). 'Imposed rate and extent of weight loss in obese men and adaptive changes in resting and total energy expenditure'. Metabolism, vol 64, no. 8, pp. 896-904.
    [Online] DOI: 10.1016/j.metabol.2015.03.011
  • Buosi, W., Bremner, DM., Horgan, G., Fyfe, CL. & Johnstone, A. (2015). 'Effect of High-Protein Breakfast Meals on Within-Day Appetite and Food Intake in Healthy Men and Women'. Food and Nutrition Sciences, vol 6, no. 3, pp. 386-390.
    [Online] DOI: 10.4236/fns.2015.63039
  • Lobley, GE., Johnstone, AM., Fyfe, C., Horgan, GW., Holtrop, G., Bremner, DM., Broom, I., Schweiger, L. & Welch, A. (2014). 'Glucose uptake by the brain on chronic high-protein weight-loss diets with either moderate or low amounts of carbohydrate'. British Journal of Nutrition, vol 111, no. 4, pp. 586-597.
    [Online] DOI: 10.1017/S0007114513002900
    [Online] AURA: BJN_2013_019620RR_revised_final_refs_no_figs.docx
    [Online] AURA: BJN_2013_019620_Figure_1.docx
    [Online] AURA: BJN_2013_019620_Figure_2.docx

Research briefs for the Knowledge Scotland web site

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.

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

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. 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.

Sustainable Diets for Scotland - A food and drink policy document by Dr Alex Johnstone pdf