Sex differences in association between sleep loss and energy metabolism; implications for lifestyle modifications (Ref: SF20/SER/MCIVER)

The incidence of reduced sleep in the UK is increasing. A report from the Sleep Council has shown that despite a recommendation of 7-9 hours of sleep per night, 74% of individuals sleep less than 7 hours (The Sleep Council, 2017). Insufficient sleep has gained attention as a potential contributor to the obesity epidemic, as the rise in the prevalence of obesity has paralleled a decline in sleep duration in Western society (Patel, 2009; Hruby and Hu, 2015). Recent studies have also suggested heterogeneity exists between men and women in how sleep duration influences behavioural and cardiometabolic risk factors (Makarem and Aggarwal, 2017). However, little research has been conducted investigating subsequent appetite regulation and metabolic markers directly between male and females, and whether meal timing also plays a significant role in appetite control and weight management.
There are inconsistencies within the current literature on whether sex differences exist in association with sleep loss for appetite control and weight gain, with some studies suggesting a significant increase in weight gain following sleep loss (5 h) in both sexes, whilst others suggest this is more pronounced in females (Lopez-Garcia et al., 2008; Patel, 2009) and others in males (Sayon-Orea et al., 2013; Watanabe et al., 2010). It is difficult to draw accurate conclusions due to the methodology differences between studies and significant differences in populations recruited, thus, difficult to compare between studies. In both men and women, short sleep affects some of the mediators of appetite control by lowering concentrations of leptin and increasing concentrations of ghrelin (Taheri et al., 2004; Spiegel et al., 2004), resulting in greater hunger and appetite, but why in some studies it is more apparent in males or females remains unclear. In addition to having an effect on energy intake, sleep may also affect energy expenditure, as it was also proposed that a reduced duration in sleep would cause daytime sleepiness, which would, in turn, lead to less physical activity (St-Onge et al., 2016; Makarem and Aggarwal, 2017).
Furthermore, sex differences in association between insufficient sleep and energy metabolism are apparent. The mechanisms underlying gender differences in these associations are not known. Therefore, aim of the proposed project is to explore these differences.

Eligibility and How to Apply:
Please note eligibility requirement:
• Academic excellence of the proposed student i.e. 2:1 (or equivalent GPA from non-UK universities [preference for 1st class honours]); or a Masters (preference for Merit or above); or APEL evidence of substantial practitioner achievement.
• Appropriate IELTS score, if required.
• Applicants cannot apply for this funding if currently engaged in Doctoral study at Northumbria or elsewhere.

For further details of how to apply, entry requirements and the application form, see
https://www.northumbria.ac.uk/research/postgraduate-research-degrees/how-to-apply/

Please note: Applications that do not include a research proposal of approximately 1,000 words (not a copy of the advert), or that do not include the advert reference (e.g., SF20/…) will not be considered.
Deadline for applications: Open
Start Date: October 2020 or March 2021
Northumbria University takes pride in, and values, the quality and diversity of our staff. We welcome applications from all members of the community. The University holds an Athena SWAN Bronze award in recognition of our commitment to improving employment practices for the advancement of gender equality.

for enquiries, contact Dr Victoria McIver ([Email Address Removed]) or Dr Ian Walshe ([Email Address Removed])