Crosstalk between circadian rhythms, sleep and eating habits to improve public health

Lifestyle changes in the past few decades have resulted in irregularity in sleep and meal timings. People are taking less sleep and resorting more to unhealthy food and eating habits. These factors are the most important health determinants. Sleep, food choices and eating habits are closely associated with each other. Thus, the crosstalk between circadian rhythms, sleep, and food needs urgent attention and discussion for better health management. Various research studies indicate that a healthy trend in sleep augments the regularity in meal timings and good eating habits. Healthy food and eating habits, in turn, boost sleep quality. Deterioration in the quality of anyone adversely affects the other. Several health disorders like obesity, diabetes, cancer, cardiovascular problems, and low immunity can be linked to these disturbances. The present review considers several previous studies to point out the inter-relationship between sleep and eating habits and the various health disorders arising from poor attention. Poor sleep promotes the tendency to eat junk food or eat at odd times, such as snacking late at night, leading to weight gain and other health problems. Junk food and unhealthy eating habits cause sleep disturbances. This inter-relationship of sleep and food preferences is important as it can have important treatment implications for health disorders arising due to these modifiable behavioural factors. Circadian alignment, improvements in sleep timings, and healthy eating habits have positive effects on other health behaviours as well. 

Short term effects of restricted food availability and peripheral leptin injections in redheaded bunting, Emberiza bruniceps

Migratory birds need continued food supply and efficient metabolic machinery to meet high energy demands of the magnanimous feat of flight. Two questions are important i.e. as to 1) how a bird adapts to a temporary food constrain on a daily basis, and 2) how peripheral leptin, an anorectic hormone, impacted feeding and migratory behaviour in buntings? The aim of this study was to induce a non-photoperiodic tweak in the physiology of redheaded buntings through exogenous leptin administration and study its effect on their food intake and migratory behaviour. Groups of male redheaded buntings, Emberiza bruniceps (n=17) were transferred from short (8L: 16D) to long (16L: 8D) days and presented with food only either for first (morning food presence, MFP) or second (evening food presence, EFP) half of the 16h lighted phase, while control group received food ad libitum. Total daily food intake (FI) did not differ significantly between the MFP, EFP and controls, but hourly FI in MFP and EFP indicated increased activity differences based on time of food availability and bird’s tendency to cache food/ recompense for food scarcity during migration. In another experiment, a chemical tweak in bird’s FI was induced by peripheral administration of leptin, to add to current understanding of transition in buntings’ metabolic efficiency during high energy demanding migratory journey. Exogenous leptin appeared to safeguard cadaveric effect of exogenous injection in migrating buntings through promoting blood cholesterol and reduced liver fibrosis. Food restriction in the morning was better responded by buntings than that in evening. Therefore, migratory buntings exhibited diurnal variation in response to food scarcity

Daily and seasonal activity patterns in blackheaded munia

504-509To test the circadian clock characteristics, activity behaviour of male blackheaded munia was recorded. Two experiments were performed. In experiment 1A, activity of munia was recorded under long days, LD (14L: 10D); and short days, SD (10L: 14D). Locomotor activity of two groups of munia exposed to equinox (12L: 12D) daylength followed by transfer of one group each to continuous dimlight (DD) and continuous bright light (LL) was recorded in experiment 1B. Experiment 2 aimed to describe seasonal trend in daily pattern of activity/rest cycle under natural illumination conditions (NDL). Hourly activity during daytime was more under SD than under LD. Munia did not exhibit bimodality in daily activity pattern; activity during morning, M (2h) was more than evening, E. A free-running activity rhythm was recorded in munia under DD; the same was arrhythmic under LL. The seasonal pattern in daily activity profiles under NDL corresponds to the seasonal changes in daylength. Daylength regulates daily and seasonal activity patterns in blackheaded munia

Disruption in daily eating-fasting and activity-rest cycles in Indian adolescents attending school.

A lifestyle with erratic eating patterns and habits predisposes youngsters to obesity. Through a two-phase feasibility study among Indian students living in the Delhi area, we longitudinally examined the following: (1) the daily eating-fasting cycles of students (N = 34) in school and college using smartphones as they transition from high school (aged 13-15 years; nIX = 13) to higher secondary school (HSSS; 16-18 years; nXII = 9) to their first year (FY) of college (18-19 years; nFC = 12); and (2) daily activity-rest cycles and light-dark exposure of 31 higher secondary school students (HSSS) using actigraphy. In phase 1, students' food data were analyzed for temporal details of eating events and observable differences in diet composition, such as an energy-dense diet (fast food (FF)), as confounding factors of circadian health. Overall, the mean eating duration in high school, higher secondary and FY college students ranged from 14.1 to 16.2h. HSSS exhibited the shortest night fasting. Although FY college students exhibited the highest fast food percentage (FF%), a positive correlation between body mass index (BMI) and FF% was observed only among HSSS. Furthermore, the body weight of HSSS was significantly higher, indicating that FF, untimely eating and reduced night fasting were important obesity-associated factors in adolescents. Reduced night fasting duration was also related to shorter sleep in HSSS. Therefore, food data were supplemented with wrist actigraphy, i.e., activity-rest data, in HSSS. Actigraphy externally validated the increased obesogenic consequences of deregulated eating rhythms in HSSS. CamNtech motion watches were used to assess the relationship between disturbed activity cycles of HSSS and other circadian clock-related rhythms, such as sleep. Less than 50% of Indian HSSS slept 6 hours or more per night. Seven of 31 students remained awake throughout the night, during which they had more than 20% of their daily light exposure. Three nonparametric circadian rhythm analysis (NPCRA) variables revealed circadian disruption of activity in HSSS. The present study suggests that inappropriate timing and quality of food and sleep disturbances are important determinants of circadian disruptions in adolescents attending school

A camera-phone based study reveals erratic eating pattern and disrupted daily eating-fasting cycle among adults in India.

The daily rhythm of feeding-fasting and meal-timing are emerging as important determinants of health. Circadian rhythm research in animal models and retrospective analyses of human nutrition data have shown that reduced length of overnight fasting or increased late night eating increases risk for metabolic diseases including obesity and diabetes. However, the daily rhythm in eating pattern in humans is rarely measured. Traditional methods to collect nutrition information through food diary and food log pay little attention to the timing of eating which may also change from day to day. We adopted a novel cell-phone based approach to longitudinally record all events of food and beverage intake in adults. In a feasibility study daily food-eating patterns of 93 healthy individuals were recorded for 21 days using camera phones. Analysis of the daily eating patterns of these individuals indicates deviation from conventional assumption that people eat three meals-a-day within a 12 h interval. We found that eating events are widespread throughout the day, with 30% consumed in evening and late night hours. There was little difference in eating pattern between weekdays and weekends. In this cohort more than 50% of people spread their caloric intake events over 15 h or longer. One decile of the cohort who were spouses of shift-workers or had flexible work schedule spread their caloric intake over 20 h. Although the nutrition quality and diversity of food consumed is different between South-East Asian and Western countries, such overall disruption of daily eating-fasting rhythm is similar. Therefore, in view of hypothesis that disrupted daily eating pattern may contribute to the global increase in metabolic diseases and modification of daily eating pattern is a potential modifiable behavior to contain these diseases, monitoring eating pattern is an important aspect of lifestyle

Circadian synchronization determines critical day length for seasonal responses

A photoperiodic species initiates fat deposition (in migrants) and gonadal recrudescence in response to a specific duration of natural daylight, called critical day length (CD), when light extends in the inductive phase of the endogenous circadian rhythm of photoinducibility (CRP). The molecular basis of species-specificCD, determined by the entrainment of the CRP, has been poorly understood. To investigate this, we measured expression levels of genes implicated in the photoperiod-induced changes in reproduction (EYA3, TSH beta, DIO2, DIO3, GNRH and GNIH) and metabolism (SIRT1, HMGCR, FASN and PPAR alpha) in photosensitive redheaded buntings subjected to light–dark cycles of varying period lengths (T-photocycles). Buntings were exposed to six T22, T24 or T26 photocycles, with 1 h additional light at night falling at different phases of the entrained CRP (T2211L = 6L:4D:1L:11D; T2411L = 6L:4D:1L:13D,T2412L = 6L:5D:1L:12D, T2413L = 6L:6D:1L:11D; T2612L = 6L:5D:1L:14D). Photoinduction at genetic and phenotypic levels in T2412L and T2413L, not T2411L, groups confirmed CD being close to 12 h in buntings under T24. Compared to T24, exposure to T22 advanced CD by 1 h, as evidenced by photoinduction in the T2211L, not T226L, group. Similarly, CD appeared to be delayed under T26, with no photoinduction in the T2612L group. Further, to show that induction of response under a T-photocycle was because of the interaction of inductive phase of the CRP with 1 h during the dark period in each cycle, not with the 6 h main light periods falling 2 h earlier each successive 24 h day in a T22 paradigm, a group of buntings was exposed to 6L:16D (T226L), to which they did not respond. The mRNA expression of genes, particularly TSH beta, DIO2, DIO3 and PPAR alpha, was significantly correlated with changes in reproductive and metabolic phenotypes. These results suggest CRP-entrainment based genetic regulation of the CD, and extend the idea that synchronization with environment is a critical measure in a seasonal species for its temporal adaptation in the wild

Eating duration for majority of individuals is longer than 12h.

<p>(A) Eating duration of 94 participants arranged with increasing time of last meal. (B) Frequency distribution of eating duration in 30min bins and cumulative percentage shows ~60% of the study cohort eat for 15 h or longer.</p

Daily eating pattern is highly erratic at individual level.

<p>(A) Scatter plot of all non-water events collected from 94 healthy subjects, where each vertical array is color coded for time-stamped ingestion events from each subject over 21 days. The subjects are arranged from left to right with increasing portion of 24 h day where they ingested food or beverages. (B) Frequency distribution of all non-water ingestion events as percentage of total number of events binned in hourly interval shows very low intake at cohort level during midnight-5am and three peaks approximately corresponding to the conventional breakfast, lunch and dinner. However, at individual level, the day to day variations in eating pattern blurs these pattern both among (C) subjects who eat during a shorter time interval or those (D) who spread their ingestion events throughout a 24 h period. Subjects in C and D are subsets of data shown in (A). Each column in Fig 2a,c,d represents data from individual subject.</p

A simple camera phone based method to collect human nutrition information.

<p>(A) Schematic of the study to collect eating pattern data for 3 weeks. (B) Work flow for data collection, download and annotation. Reminders were sent to the user’s preferred phones at random time of the day. Although the user could potentially review collected data, it did not affect their body weight at baseline and after 3 weeks of data collection as seen in individual body weights (C) and (D) in median body weight (±max/min range, paired t-test p>0.05).</p