Effect of consuming a late-night high-protein/moderate-carbohydrate vs. low-protein/high-carbohydrate meal by night workers on their food perceptions later during the day: a randomized crossover study.

It is typical of night workers to consume a large dinner meal before their work shift, even though this practice may increase the risk for metabolic disorders. Night workers usually eat at night to socialize with colleagues as well as to stay alert and to avoid upset stomach during the night shift. However, little is known if and how the composition of the nighttime meal by night shift workers influences their food perceptions and eating behavior later during the day. The aim of this study was to analyze the effect of a high-protein/moderate-carbohydrate (HP/MCHO) meal vs. low-protein/high-carbohydrate (LP/HCHO) meal eaten at night by night-shift workers on their food consumption and perceptions later during the day. Fourteen male night shift workers were followed-up for 7 days for their eating and sleep habits. Then, participants underwent two isocaloric dietary events - one event a HP/MCHO meal containing 45% carbohydrate, 35% protein, and 20% fat and the other event a LP/HCHO meal containing 65% carbohydrate, 15% protein, and 20% fat, with a 6-day washout period between them - at 01:00 h during their night shift. Thereafter throughout the day, participants filled a food register of all the food consumed and perceptions, including hunger before meals, enjoyment of meals, and satiety. Generalized estimating equation analyses were used to examine the effect of both conditions on food consumption and food perceptions. Appetite for salty food snacks was greater after the HP/MCHO condition than after the LP/HCHO condition (p = .041). During the day following consumption of the nighttime HP/MCHO vs. LP/HCHO meal, there was higher percentage of carbohydrate consumption during lunch and a lower percentage of fat consumption during dinner (48.14% vs. 36.98% and 27.34% vs. 40.39%, respectively). These findings suggest the composition in terms of carbohydrates, protein, and fats of the meal consumed for the night shift by night workers may affect later during the day both food consumption and perceptions.

Vulnerabilidade de adolescentes em pesquisa e prática clínica / Vulnerability of adolescents in clinical research and practice / La vulnerabilidad de los adolescentes en la investigación y en la práctica clínica

Resumo Os adolescentes são considerados grupo vulnerável e exposto a diferentes ameaças à saúde, tornando-se necessária a discussão sobre aspectos éticos relacionados a sua participação em pesquisa e prática clínica. Por meio de revisão integrativa de literatura foram selecionados estudos que abordaram aspectos bioéticos relacionados à vulnerabilidade de adolescentes nos últimos quinze anos. Nove artigos atenderam aos critérios pré-estabelecidos para o estudo e foram agrupados em três categorias: 1) trabalhos que pontuaram a compreensão psicológica e cognitiva do adolescente ao participar de pesquisa científica; 2) estudos que enfatizaram aspectos relacionados a decisões médicas; e 3) estudos que abordaram a temática da sexualidade na adolescência. Após análise dos estudos selecionados, verificou-se que não é possível chegar a consenso válido para todas as situações que envolvem adolescentes em pesquisa e prática clínica.

Abstract Adolescents are considered vulnerable and exposed to different threats to health group, making it necessary discussion about ethical aspects related to their participation in research and clinical practice. The employed methodology was an integrative literature review and it was selected studies that approached the subject "bioethical matters related to vulnerability of adolescents" within the last fifteen years. Nine articles included the pre-established criteria to the study, grouped into three categories: 1) works that mentioned the psychological-cognitive comprehension of adolescent to participate in scientific research; 2) works emphasizing aspects related to medical decisions; and 3) studies approaching the issue of sexuality in adolescence. The analysis of selected studies found out it is not possible to reach a valid consensus to all situations involving adolescents in research and clinical practice.

Resumen Los adolescentes son considerados como grupo vulnerable y expuesto a diferentes amenazas en el ámbito de la salud, por lo cual es necesario que exista un debate sobre los aspectos éticos relacionados con su participación en la investigación y en la práctica clínica. Por medio de una revisión integradora de la literatura, se seleccionaron estudios que abordaban aspectos bioéticos relacionados con la vulnerabilidad de los adolescentes en los últimos quince años. Nueve artículos contemplaban los criterios preestablecidos para el estudio y se agruparon en tres categorías: 1) trabajos que contemplaban la comprensión psicológica y cognitiva del adolescente al participar en la investigación científica; 2) estudios que enfatizaban los aspectos relacionados con las decisiones médicas; y 3) estudios que abordaban la sexualidad en la adolescencia. Después del análisis de los estudios seleccionados, se verificó que no es posible llegar a un consenso válido para todas las situaciones que involucran adolescentes en la investigación y en la práctica clínica.

Social Jetlag Among Night Workers is Negatively Associated with the Frequency of Moderate or Vigorous Physical Activity and with Energy Expenditure Related to Physical Activity.

This cross-sectional study analyzed the association between physical activity (PA) and social jetlag (SJL) among shift workers. We evaluated 423 employees, aged between 18 and 60 years, who worked in a poultry-processing company in Brazil. Physical activity levels (PAL) were determined by the short form of the International Physical Activity Questionnaire (IPAQ-SF). SJL was calculated as the absolute difference between the time of mid-sleep on work and free days. The percentage of workers insufficiently active was high on all shifts, with no significant differences between the 3 shifts. The amount of time spent in sedentary behavior on workdays did not differ between shifts. Among night-shift workers, negative associations were observed between SJL and 1) the duration and weekly energy expenditure while walking; 2) the frequency of moderate and vigorous PA; and 3) the total energy expenditure related to PA. Even though PAL did not differ among workers on different shifts, we found a high prevalence of subjects who were insufficiently active or too sedentary among all groups. Also, SJL was negatively associated with PA in night-shift workers. These results suggest that PA should be encouraged among shift workers and that SJL may be an important factor in reducing PA in this cohort.

The association between anxiety, hunger, the enjoyment of eating foods and the satiety after food intake in individuals working a night shift compared with after taking a nocturnal sleep: A prospective and observational study.

Subjective responses to meals are altered by shortened sleep time and anxiety state, but this effect has been poorly studied in shift workers - who act as a typical model concerning sleep restriction and present high levels of anxiety. The objective of this study was to compare subjective perceptions of meals and the levels of anxiety in the same subjects after working night shifts and after taking a nocturnal sleep, and to investigate associations between the responses to meals and the levels of anxiety under these two conditions. The study evaluated 34 male permanent night-shift workers who worked a 12-h shift followed by a 36-h rest period. Evaluations included: sleep pattern (on three days after working night shifts and after sleeping at night); hunger, enjoyment of eating foods and satiety after a meal (evaluated by visual analogue scales on three non-consecutive days after working night shifts and after nocturnal sleeps); and state of anxiety (on a day after working a night shift and a day after a nocturnal sleep). In the days following a night shift, workers had higher mean hunger scores before lunch and higher anxiety scores than when they had slept at night (p = 0.007 and 0.001, respectively). Linear regression indicated that, after a night shift, anxiety scores were negatively associated with hunger before breakfast (p = 0.04) and lunch (p = 0.03), the enjoyment of eating foods (p = 0.03) and the number of meals eaten during the course of the 24 h (p = 0.03). It is concluded that night shifts increase mean hunger and anxiety scores. Anxiety levels seem to interfere with the responses associated with food consumption.

Whey protein improves HDL/non-HDL ratio and body weight gain in rats subjected to the resistance exercise

The aim of this study was to evaluate the effects of resistance exercise, such as weight-lifting (WL) on the biochemical parameters of lipid metabolism and cardiovascular disease risk in the rats fed casein (control) or whey protein (WP) diets. Thirty-two male Fisher rats were randomly assigned to sedentary or exercise-trained groups and were fed control or WP diets. The WL program consisted of inducing the animals to perform the sets of jumps with weights attached to the chest. After seven weeks, arteriovenous blood samples were collected for analysis. The WL or WP ingestion were able to improve the lipid profile, reducing the TC and non-HDL cholesterol concentrations, but only WP treatment significantly increased the serum HDL concentrations, thereby also affecting the TC/HDL and HDL/non-HDL ratios. However, WL plus WP was more effective in improving the HDL/non-HDL ratio than the exercise or WP ingestion alone and the body weight gain than exercise without WP ingestion.