Alan's early work at LSHTM focused on nutrition in older age, and he conducted a series of randomised controlled trials to determine the effectiveness of nutrition interventions for the maintenance of health and function in later life.

Since 2009, Alan's research has explored the interactions between the environment, agriculture, nutrition and health. In 2010, Alan was part of the inter-disciplinary team that set up the Leverhulme Centre for Integrative Research on Agriculture and Health (LCIRAH) that conducts inter-sectoral research linking agriculture with health in low and middle income country settings. Between 2012 and 2018, Alan led the intervention research pillar of the DFID-funded research consortium Leveraging Agriculture for Nutrition in South Asia (LANSA).

Alan now leads the Sustainable and Healthy Food Systems (SHEFS) research programme funded by the Wellcome Trust Our Planet, Our Health priority area, that specifically links the environment, food system and health with a focus on India, South Africa and the UK.  Alan works with an exciting team of researchers with expertise in epidemiological and mathematical modelling, soil and agricultural science, environmental assessment, climate science, nutrition and health.