Your sleep the night before.

Previous day physical activity.

What you eat for breakfast.

Blood glucose response to breakfast.

Nutritional factors linked to energy intake Numerous studies have demonstrated that total and partial sleep deprivation impairs postprandial handling of glucose, lipids and also alters appetite regulation, favouring increased energy intake (e.g., Donga et al., 2010; Gonnissen et al., 2013; Wang et al., 2016; Sweeney et al., 2017, Davies et al., 2014; Chuaet al., 2015, Broussard & Brady, 2010; Bellet al., 2013; Nesset al., 2019, Mullington et al., 2003; Pejovic et al., 2010, Spiegel et al., 2004; Schmid et al., 2008).

Blood glucose responses A later sleep midpoint, largely driven by going to bed earlier rather than waking up later is associated with improved blood glucose responses (Tsereteli et al. 2021).

Alertness By going to bed earlier and increasing sleep duration & quality you may improve your return to full alertness in the morning (free of sleepiness) and overall health.

Long-term metabolic and mental health It has been shown that six to eight hours of sleep, as well as less fragmented sleep, correlates with better long-term metabolic and mental health (e.g. Zhu et al. 2021). Swanson et al. 2023 indicate that having a sleep midpoint outside of 2:00-4:00 AM significantly correlated with depressive symptoms.

Cardiovascular diseases Gupta et al. 2021, Yan et al. 2021 and others have shown that sleep duration and efficiency is associated with cardiovascular risk mortality, 10-year Atherosclerotic Cardiovascular Disease (ASCVD) risk. Full et al. 2023 have found that compared with participants with more regular sleep timing participants with irregular sleep timing were more likely to have high coronary artery calcium burden.

Type 2 Diabetes Possible U shaped relationship for sleep midpoint and T2D risk (Early OR: 1.13 [1.04–1.22] and Late OR: 1.14 [1.03–1.26]). Sleep midpoint outside of 2:00-4:00 AM was significantly associated with depressive symptoms (β = 0.88, 95% CI = 0.06, 1.70). Later sleep midpoint is associated with increased stress and worse mental wellbeing (B = -1.243, SE 0.315, β = -0.220).

Hypertension Highly irregular sleep duration routines have been associated with a 9 to 15% increase in hypertension risk. Scott et al. 2022 reported that a 38-minute increase in sleep midpoint irregularity increased hypertension risk by 11%.