Dietary taste patterns and diet quality of female nurses around the night shift.

PURPOSE: Night shift workers are at risk of making poor food choices: e.g. sleep deprivation may lead to higher food intake with innate preferred tastes, such as sweet, savoury and fatty foods. Therefore, better insight in dietary taste patterns of night shift workers may improve the understanding of their food choices. METHODS: This observational study assessed dietary taste patterns of 120 female night shift working nurses and compared them to 307 women of a reference population. Dietary intake, assessed with 24-h dietary recalls, was combined with a taste intensity database, including taste profiles of 557 foods. The contribution to the daily intake of 6 taste clusters was assessed: fat, neutral, sweet/fat, sweet/sour, salt/umami/fat and bitter. RESULTS: During night shifts, nurses consumed a significantly higher energy percentage (en%) of 'neutral' (5.9 en%), 'sweet/sour' (8.1 en%) and 'sweet/fat' (6.5 en%) tasting foods and a lower en% of 'fat' (- 17.1 en%) and 'bitter' (- 2.1 en%) tasting foods than outside the night shift. They consumed a larger en% from foods with a 'sweet/sour' (1.9 en%) taste and a lower en% from foods with a 'bitter' (- 2.1 en%) taste than the reference population, irrespective of age, BMI and smoking status. A higher en% and gram% of 'fat' tasting foods and a higher gram% 'fat/salt/umami' tasting foods were associated with lower diet quality. CONCLUSION: Our results only partly support our hypothesis that nurses would select foods with more innate taste preferences. In addition, fat and savoury tasting foods were negatively associated with their diet quality.

The Effect of Meal Glycemic Index and Meal Frequency on Glycemic Control and Variability in Female Nurses Working Night Shifts: A Two-Arm Randomized Cross-Over Trial.

BACKGROUND: Night shift workers are exposed to circadian disruption, which contributes to impaired glucose tolerance. Although fasting during the night shift improves glucose homeostasis, adhering to this dietary strategy may be challenging. OBJECTIVES: This study evaluated the effect of fasting compared with the consumption of meals with different combinations of glycemic index (GI, low or high) and frequency (1 or 3 times) during the night shift on continuous glucose monitoring metrics. METHODS: A 2-arm randomized cross-over trial was conducted on female nurses working night shifts. In each of those arms, the participants were either provided with no meal (fasted), low GI, or high-GI meal during the night shift with a meal frequency according to which arm they were randomly allocated to, either 1-MEAL or 3-MEAL. Outcome variables were glycemic control and variability (GC and GV) metrics during the night shift (21:30-7:00), in the morning after the night shift (07:00-13:00), and in the 24 h period (18:00-18:00). RESULTS: Compared to no meal, the consumption of 1 high-GI meal increased all GV metrics not only during the night shifts but also in the morning, for instance, as observed in the coefficient of variation (ß = 0.03 mmol/L; 95% CI: 0.01, 0.05), and GV percentage (ß = 4.13; 95% CI: 2.07, 6.18). The consumption of 1 or 3 low GI meals did not raise GC or GV metrics except for continuous overall net glycemic action during the night shifts after consuming 3 low GI meals. When controlling for GI, night shift meal frequency did not affect any metrics in any timeframe. CONCLUSIONS: High meal GI but not higher meal frequency during the night shift increased GC and GV in female night shift workers. Results for 1 low-GI meal during the night shift were not different from a glucose profile after no meal. This trial was registered at trialsearch.who.int as NL8715.

Macronutrient intake and alertness during night shifts - the time interval matters.

Background: Working night shifts is associated with higher safety risks due to shift work-related fatigue. Nutrition, especially certain (macro) nutrient compositions, has been suggested to reduce fatigue, however, results of studies are contradictory. This could be explained by differences in the time interval investigated between the consumption of a meal and measurement of cognitive performance. Therefore, this observational study investigated the association between macronutrient intake and objective alertness at different time intervals during the night shift in nurses. Methods: 128 nurses, aged 20-61 years, completed an alertness test (Psychomotor Vigilance Task) during the night shift and a 24-h dietary recall after the night shift. This was repeated three times, always on the first night shift in a night shift series. The associations between macronutrient intake 0 to 1, 1 to 2, and 2 to 3 h before the PVT with alertness during the night shift were analyzed through Linear Mixed Models. The basic model was adjusted for age and gender and the adjusted model additionally for BMI, start time of PVT and energy and caffeine intake during the relevant time interval. Results: Protein intake was not associated with objective alertness levels, while fat and carbohydrates intake had opposite associations with objective alertness levels over similar time intervals. Fat intake up to 1 h prior to the PVT was borderline associated with a longer median reaction time (RT) (ß = 9.00 ms/10 g fat, 95% CI: -0.21, 18.20), while a higher carbohydrate intake up to 1 h prior to the PVT was borderline associated with shorter median RTs (ß = -3.89, 95% CI: -7.85, 0.06). A higher fat intake 2 to 3 h prior to the PVT was associated with less lapses (log transformed ß = -0.16; 95% CI: -0.31, -0.02), while a higher carbohydrate intake 2 to 3 h prior to the PVT was associated with more lapses (ß = 0.06, 95% CI: 0.01, 0.12). Conclusion: Our results contribute to understanding the association between macronutrient intake, as part of a mixed meal, and alertness levels. Conflicting results from previous studies may probably be due to time differences between macronutrient intake and alertness testing.

Development and evaluation of a diet quality screener to assess adherence to the Dutch food-based dietary guidelines.

The Eetscore FFQ was developed to score the Dutch Healthy Diet index 2015 (DHD2015-index) representing the Dutch food-based dietary guidelines of 2015. This paper describes the development of the Eetscore FFQ, a short screener assessing diet quality, examines associations between diet quality and participants' characteristics, and evaluates the relative validity and reproducibility of the Eetscore FFQ in a cross-sectional study with Dutch adults. The study sample consisted of 751 participants, aged 19-91 years, recruited from the EetMeetWeet research panel. The mean DHD2015-index score based on the Eetscore FFQ of the total sample was 111 (sd 17·5) out of a maximum score of 160 points and was significantly higher in women than in men, positively associated with age and education level, and inversely associated with BMI. The Kendall's tau-b coefficient of the DHD2015-index between the Eetscore FFQ and the full-length FFQ (on average 1·7-month interval, n 565) was 0·51 (95 % CI 0·47, 0·55), indicating an acceptable ranking ability. The intraclass correlation coefficient between DHD2015-index scores derived from two repeated Eetscore FFQ (on average 3·8-month interval, n 343) was 0·91 (95 % CI 0·89, 0·93) suggesting a very good reproducibility. In conclusion, the Eetscore FFQ was considered acceptable in ranking participants according to their diet quality compared with the full-length FFQ and showed good to excellent reproducibility.

The association between eating frequency with alertness and gastrointestinal complaints in nurses during the night shift.

We investigated the association of the number of eating occasions and energy intake with alertness and gastrointestinal (GI) complaints in nurses during their night shift. During this observational study we collected data on anthropometrics and demographics, eating frequency, energy intake, alertness and GI complaints in 118 healthy female nurses, aged 20 to 61 years. Nurses completed an alertness test (psychomotor vigilance task) during the night shift and a 24-hr dietary recall and a questionnaire about GI complaints after the night shift. This was repeated three times, always on the first night shift in a night shift series. The number of eating occasions during the night shift was negatively associated with reaction times (ß = -4.81 ms, 95% confidence interval [CI] -9.14 to -0.48; p = .030), and number of lapses (ß = -0.04, 95% CI -0.07 to -0.00; p = .030). However, the number of eating occasions was not associated with subjective alertness and GI complaints. Energy intake during the night shift was not associated with objective or subjective alertness or with GI complaints. These associations were independent of caffeine intake, age, body mass index and dependence among the repeated measurements. The present study showed that eating frequency was positively associated with objectively measured alertness levels in female nurses during the night shift. The results need to be confirmed in an intervention study, where also timing, size and composition of the meal will be taken into account. In practice, optimising nutritional guidelines on these aspects could lead to faster responses, less (medical) errors, and a better wellbeing of night shift workers.

Human spatial memory implicitly prioritizes high-calorie foods.

All species face the important adaptive problem of efficiently locating high-quality nutritional resources. We explored whether human spatial cognition is enhanced for high-calorie foods, in a large multisensory experiment that covertly tested the location memory of people who navigated a maze-like food setting. We found that individuals incidentally learned and more accurately recalled locations of high-calorie foods - regardless of explicit hedonic valuations or personal familiarity with foods. In addition, the high-calorie bias in human spatial memory already became evident within a limited sensory environment, where solely odor information was available. These results suggest that human minds continue to house a cognitive system optimized for energy-efficient foraging within erratic food habitats of the past, and highlight the often underestimated capabilities of the human olfactory sense.

Development and evaluation of the Dutch Healthy Diet index 2015.

OBJECTIVE: To update the Dutch Healthy Diet index, a measure of diet quality, to reflect adherence to the Dutch dietary guidelines 2015 and to evaluate against participants' characteristics and nutrient intakes with the score based on 24 h recall (24 hR) data and FFQ data. DESIGN: The Dutch Healthy Diet index 2015 (DHD15-index) consists of fifteen components representing the fifteen food-based Dutch dietary guidelines of 2015. Per component the score ranges between 0 and 10, resulting in a total score between 0 (no adherence) and 150 (complete adherence). SETTING: Wageningen area, the Netherlands, 2011-2013. SUBJECTS: Data of 885 men and women, aged 20-70 years, participating in the longitudinal NQplus study, who filled out two 24 hR and one FFQ, were used. RESULTS: Mean (sd) score of the DHD15-index was 68·7 (16·1) for men and 79·4 (16·0) for women. Significant inverse trends were found between the DHD15-index and BMI, smoking, and intakes of energy, total fat and saturated fat. Positive trends were seen across sex-specific quintiles of the DHD15-index score with energy-adjusted micronutrient intakes. Mean DHD15-index score of the FFQ data was 15·5 points higher compared with 24 hR data, with a correlation coefficient of 0·56 between the scores. Observed trends of the DHD15-index based on FFQ with participant characteristics, macronutrient and energy-adjusted micronutrient intakes were similar to those with the DHD15-index based on 24 hR. CONCLUSIONS: The DHD15-index score assesses adherence to the Dutch dietary guidelines 2015 and indicates diet quality. The DHD15-index score can be based on 24 hR data and on FFQ data.