Chronotype: Implications for Epidemiologic Studies on Chrono-Nutrition and Cardiometabolic Health

Abstract

Chrono-nutrition is an emerging research field in nutritional epidemiology that encompasses 3 dimensions of eating behavior: timing, frequency, and regularity. To date, few studies have investigated how an individual's circadian typology, i.e., one's chronotype, affects the association between chrono-nutrition and cardiometabolic health. This review sets the directions for future research by providing a narrative overview of recent epidemiologic research on chronotype, its determinants, and its association with dietary intake and cardiometabolic health. Limited research was found on the association between chronotype and dietary intake in infants, children, and older adults. Moreover, most of the evidence in adolescents and adults was restricted to cross-sectional surveys with few longitudinal cohorts simultaneously collecting data on chronotype and dietary intake. There was a gap in the research concerning the association between chronotype and the 3 dimensions of chrono-nutrition. Whether chronotype modifies the association between diet and cardiometabolic health outcomes remains to be elucidated. In conclusion, further research is required to understand the interplay between chronotype, chrono-nutrition, and cardiometabolic health outcomes.

Is Abdominal Fat Distribution Associated with Chronotype in Adults Independently of Lifestyle Factors?

“…In this scenario, chrononutrition is an emerging research field [15]: timing, frequency, and regularity of daily life and relative fasting-feeding cycles seem to play a significant role in the relationship between diet and cardiometabolic health [31]. Multiple oscillators distributed throughout the body along with a central pacemaker located within the suprachiasmatic nucleus of the hypothalamus coordinating the whole structure are the main components constituting the mammalian circadian system [32].…”

“…Among the risk factors of abdominal obesity, chronotype and circadian rhythms are emerging [15]. The interindividual differences observed in the natural propensity of behavioural manifestation relative to light-dark cycle are captured by a biological construct referred to as chronotype [16].…”

“…Factors determining an individual's chronotype are very complex, i.e., including both internal (e.g., cortisol, melatonin, and clock gene expression) and environmental (e.g., light-darkness cycle, seasons, cultural influences, social habits, urban lifestyle) factors [14,15]. Mounting literature suggests that the mismatch between light-dark cycle and social life, typical of E-Types, represents a risk factor for obesity and related cardiometabolic diseases [17,18].…”

“…In this perspective, it is possible to interpret the higher rates of sleep-related problems observed in E-types as a result of a daily social programme imposing a rhythm which is markedly misaligned with the biological one [19]. E-Types are mostly younger male adults, and they tend to have health-impairing behaviours [15,20], such as a lower adherence to a balanced diet, sedentary activity, smoking, and poorer sleep patterns, with respect to M-Types, [11,14,15], showing altered body composition and higher prevalence of metabolic disorders [12,13].…”

The Circadian Syndrome: is the Metabolic Syndrome and much more!

“…Herein we discuss research findings relating to the proposed Circadian Syndrome risk components and comorbidities (Table 2). Hypertension Lack of nocturnal decline in blood pressure [30,62] High blood pressure [22] Lipids Disrupted lipid homeostasis [69,70] Obesity Disrupted diurnal rhythms in the white adipose tissue transcriptome [73] Obesity [22] Blood glucose levels Disrupted daily rhythms in blood glucose levels and glucose intolerance [17,21,75] Disrupted daily rhythms in blood glucose levels and glucose intolerance [22] Fatty liver Disrupted triglyceride accumulation, inflammation, oxidative stress and mitochondrial dysfunction [29] Depression Circadian disruption increases the incidences of depression [86,87] Circadian disruption increases the incidences of depression [22,83,84,[105][106][107][108][109][110] Sleep disturbances Circadian disturbances result in sleep loss and mistimed sleep [56,97] Proposing a Circadian Syndrome: Cardiovascular-related components Circadian oscillations have been reported for both physiological CVD regulation including heart rate and blood pressure [57], for cardiac disorders including arrythmias [58,59], and there is circadian variation in frequency of onset of myocardial infarction and sudden cardiac death [19,60].…”