Modern lifestyles, particularly shift work, have changed the daily
rhythms of life, but is this a cost to health? What preventative
measures for employers and employees can be taken?
Shift work and its effects on health
Approximately one in five workers in Europe is employed on a shift
work basis.
1
Shift work comprises work patterns that do not follow the
conventional 8hour daytime working period, including night shifts,
rotating shift work, and/or irregular working hours.
2
Compared to
individuals who work standard hours, shift workers may be at higher
risk of a wide range of conditions such as obesity, type 2 diabetes,
cardiovascular disease, digestive problems, sleep disorders, depression,
and vitamin D deficiency (lack of exposure to sunlight).
3–6
For example,
night shift work is estimated to increase coronary heart disease risk by
40%.
5
How might shift work cause these negative health effects?
Disrupted metabolism
Some of these health issues may in part be related to the lifestyle and
irregular eating patterns due to shift work, but may also reflect deeper metabolic disturbances.
6
Working at night essentially
goes against the body’s circadian rhythm, also known as the “body clock”, a set of distinct physiological fluctuations throughout
the 24hour day linked to sunlight and temperature.
4
A recent study shows that prolonged sleep restriction and circadian
disruption alter metabolism, decreases resting metabolic rate (basal energy use), increases blood glucose (sugar) levels
(inadequate insulin response after a meal), and thus increases the risk of obesity and diabetes.
7
Additionally psychosocial
stress and physical inactivity may contribute to a disrupted metabolism.
4
Eating behaviour of shift workers
Shift working can affect energy distribution over the course of the day. Shift workers tend to snack more frequently instead of
having full meals, but overall this does not appear to impact total energy intake. Few studies adequately assess nutrient
intakes and the impact of timing of intake.
4
Factors that may influence food consumption include disruption of meal time
routines with family and friends, eating alone, and the quality of food and dining facilities. In addition, time for food
consumption is seldom prioritised and can be constrained by staffing levels and shift schedules.
4,6
More research is required to elucidate the relationship between disruption of the circadian clock, lifestyle and metabolic
conditions experienced by shift workers.
3
This will be addressed by a new EUfunded project, EuRhythDia, on the effect of
lifestyle interventions (diet, exercise, light exposure and melatonin intake).
8
It is difficult to make dietary recommendations for shift workers, but possible to identify broad guiding principles for employees
and employers to promote healthier lifestyles, in addition to general healthy eating and fatigue management guidelines.
Food and drink choices during shifts and inbetween shifts:
l
Workplaces should develop a nutrition strategy that ensures that healthy choices of foods and beverages are offered in
a relaxed eating environment.
l
Shift schedules should be designed to give employees adequate time between shifts to allow them to maintain a healthy
lifestyle – to have regular meal times, exercise and sleeping patterns.
4
l
Shift workers should stick as closely as possible to a normal dayandnight pattern of food intake. Avoid eating, or at
least restrict energy intake, between midnight and 6 am, and attempt to eat at the beginning and end of the shift.
4
For
example, afternoon workers should have their main meal in the middle of the day, rather than middle of their shift.
Night workers should eat their main meal before their shift starts, at regular dinnertime.
9
Eating breakfast before day
sleep will help to avoid wakening due to hunger. However, it is advisable for this meal to be small, a large meal (1–2
hours before sleep) could cause difficulty in falling asleep.
4
l
Drink fluids, regularly, to help prevent dehydration which can increase tiredness.
l
Stimulants such as caffeine can remain in the body for a few hours after consumption and may increase alertness, and
therefore interfere with sleeping. If shift workers feel that they require caffeine during the shift, aim to have this at the
start, and switch to noncaffeinated drinks as the shift progresses. Avoid alcohol as a means of getting to sleep.
9
References
1. Eurofound (2012). Fifth European Working Conditions Survey, Publications Office of the European Union, Luxembourg.
2. Eberly R & Feldman H. (2010). Obesity and shift work in the general population. Internet J Allied Health Sci Prac 8(3).
3. Antunes LC et al. (2010). Obesity and shift work: chronobiological aspects. Nutr Res Rev 23:155–168.
4. Lowden A et al. (2010). Eating and shift work – effects on habits, metabolism and performance. Scand J Work Health 36
(2):150–162.
5. Thomas C & Power C. (2010). Shift work and risk factors for cardiovascular disease: a study at age 45 years in the
1958 British birth cohort. Eur J Epidemiol 25(5):305–14.
6. Atkinson G et al. (2008). Exercise, energy balance and the shift worker. Sports Med 38(8):671–685.
7. Buxton OM et al. (2012). Adverse metabolic consequences in humans of prolonged sleep restriction combined with
Shift work: implications for health and nutrition
circadian disruption. Sci Transl Med 4(129):129ra43.
8. EU project EuRhythDia:
9. Dietitians of Canada (2010). Fact Sheet – Are there special nutritional considerations for shift workers? Canadian Health
Network:
http://gov.ns.ca/psc/pdf/employeeCentre/healthyWorkplace/healthyEating/03_16_ShiftWork.pdf
2
New research suggests that the food preferences of young children could be related
to their risk of becoming obese later in life. Parents and caregivers can influence
young children’s food preferences, and here we discuss strategies that may be
helpful and those which may be counterproductive.
Obesity – genetic and environmental
Obesity is a complex condition influenced by both genetic and environmental factors. For
adults it is classified as a body mass index (BMI) of ≥30 kg/m
2
, while overweight is 25–29.9
kg/m
2
. For children, overweight and obesity is defined using growth charts and adjusted BMI
cutoff points. Currently in Europe, one in five children is overweight or obese.
1
These
children have an increased risk of developing chronic diseases such as heart disease and
diabetes.
Genes define the propensity to become overweight, and diet and physical activity can
determine to what extent that propensity becomes a reality. In addition, behaviours are
influenced by the environment. Past research has analysed women’s diets during pregnancy
and the differences between feeding practices in relation to the risk of obesity.
2
Environmental interventions to prevent obesity in children have also been implemented but
mostly at schools.
New research sheds light on the diet of young children and how caregivers (parents) might be directly or indirectly influencing their children’s
food preferences at home, which in turn affect energy intake. The age range of focus is from the time solid foods are introduced until children
enter primary school (around age five or six). Researchers hypothesise that there is an association between children’s food preferences at
these ages and their risk of obesity. Eating habits developed when young influence lifelong eating behaviours.
3
Parents can strongly influence
children’s food choices because they have increased control over children’s actions at this age, and outside influences (school, peers) are
usually minimal. Once children begin school, most have already developed their food preferences (likes and dislikes) so achieving behaviour
change is more difficult. Parents’ positive influences are vital for establishing healthy lifestyle behaviours in their children.
3
Preferences in infancy
Infants have innate preferences towards certain taste qualities and dislikes of other tastes.
2
Infants prefer sweettasting foods and reject bitter
foods such as certain vegetables. This reflects an evolutionary response that was historically useful because the sweet taste signalled sources
of energy (calories), while bitter tastes signalled foods that might be toxic. Some researchers believe that infants begin to accept bitter tastes
around the age of 14–180 days.
4
As children grow up, they may refuse foods and become picky about certain foods. A reluctance to try new foods is called neophobia.
3
Neophobia seems to be minimal around six months of age, so infants may be more willing to try new foods at this age.
4
A commonly rejected
category of foods is vegetables, for which there appears to be a universal dislike, readily leading to uneaten healthy nutrients. It presents many
challenges for parents, and they respond in a variety of ways. Some give their children what they want to pacify them. Others restrict highly
palatable foods, pressure to eat fruits and vegetables, provide rewards for eating nutritious foods, or do nothing at all. Recent research
provides answers as to why young children act this way towards food and how parents can best respond to encourage healthy eating habits that
will last into adulthood. Parental actions that seem intuitive – restricting less nutritious foods, pressuring to eat nutrientrich foods, or rewarding
for good behaviours – might actually be counterproductive and lead to unhealthy habits, which might lead to obesity for children later in life.
5
Restriction and pressure
Sometimes parents restrict highly palatable (and often energy dense) foods from their children’s diets hoping children choose healthful
alternatives, but this often has the opposite effect. Restricting a tasty food from children usually increases their desire for it. In addition, some
studies have found that children with restrictive parents were more likely to be overweight later in life.
3
Restriction can also lead children to eat
when they are not hungry. This in turn could inhibit the ability to selfregulate – to learn to pay attention to one’s own physical and internal cues
of hunger and satiety. In contrast, a moderate amount of restriction could be beneficial. Children whose parents moderately restricted what
they ate were found to consume fewer calories overall than children whose parents used high or low amounts of restriction.
3
More research is
needed to define moderate restriction. Older children who said their parents were authoritative – active in meal times but not restrictive – ate
more fruit, fewer sweets and fatty snacks, and breakfast more days of the week than children who claimed their parents were neglectful.
2
In contrast to restriction, some parents pressure their children to eat fruits and vegetables, which could have a negative effect. Pressuring
children often deters them from eating certain foods and has also been associated with a lower body weight and picky eating. However, this
does not mean that pressuring causes a lower body weight or picky eating; instead, it is thought that when parents have children who are picky
eaters or are underweight, they are more likely to pressure them to eat.
3
Many scientists discourage pressuring because it can create a
negative eating environment and prohibit children from selfregulating their hunger and satiety cues.
Rewarding
Rewarding children for healthy eating is another common practice among wellintentioned parents. However, rewarding with a highly palatable
food can defeat the purpose of rewarding. When a tasty food is offered as a reward, children’s desire for the 'reward' food increases over the
food the parents are trying to encourage them to eat. In addition, rewarding does not allow children to develop intrinsic motivation for healthy
eating. Parents may see better results from offering a variety of foods starting at a young age and repeating exposure to foods even if the child
does not like them at first.
6
At the same time, psychologists recognise that humans often need rewards for motivation. A UK study found that exposing four to six year olds
to vegetables and giving them a sticker for eating them was the most effective at increasing their intake of vegetables compared to exposure
plus verbal praise or just exposure.
3
Modelling
Children model the behaviours of those around them, and when children are young, parents (and sometimes siblings) are the main role models
in their lives.
5
Therefore, children are likely to adopt the same eating habits as their parents. Since parents have the biggest influence at this
time in a child’s life, it is important that they set good examples.
The environment is partly to blame for less and poor modelling. People eat away from home more often, which can mean poorer food choices
are modelled. Likewise, fewer family meals are eaten at home, an opportune place for parents to offer a model of healthy eating behaviours.
7
Neophobia can often be overcome in children who have positive role models. Children are more likely to try unfamiliar foods if they have
observed someone else eating them. In addition, when parents take a bite of their children’s food and show signs of enjoyment, children are
more likely to try the food.
8
A survey of over 550 families found that parents’ fruit and vegetable consumption was the strongest predictor of a child’s intake of those foods.
There are two main ways modelling can increase consumption: observation could change behaviours directly or it could increase the possibility
of consumption thereby promoting liking through increased taste exposure.
8
Either way, scientists recommend that parents be active and
positive role models. This means eating a wide variety of foods and consuming fruits and vegetables regularly. In addition, parents can expose
their children to fruits and vegetables through movies, books, or gardening.
3
Parental influence on children’s food preferences and energy intake
3
What else can parents do?
Raising children to adopt healthy eating behaviours may seem daunting, but it does not have to be. Most importantly, parents should expose
their children to a wide variety of foods starting at an early age. Usually children reject certain foods because they are new to them. It may
take several exposures before they develop a liking to these initially unfavourable foods. The exact number of exposures needed depends on a
number of factors including the age of the child, initial liking and novelty of the food, and previous exposures to new flavours. One exposure
might be enough for some children, but others might require repeated exposure.
9
Consuming appropriate portion sizes is also critical for a healthy diet. One study found that when a portion size of carrots was doubled and
served as a first course, children ate 47% more of them.
3
Increasing the portion size of vegetables and decreasing the portion size of energy
dense, yet nutrientpoor foods would lead to healthier eating.
Notably, the way fruits and vegetables look on the plate influences the likelihood that children will try them. One study found that children ate
more fruit when it was boatshaped compared to fruit served simply on a white plate.
3
In conclusion, parents should be active in their children’s meal times without being overbearing.
Parents can positively influence their young children’s diets by doing some or all of the following:
l
Be a positive role model by eating a wide variety of fruits and vegetables.
l
Provide a variety of nutrientdense foods such as fruits and vegetables to your children starting when solid foods are introduced.
l
Schedule meal times, and eat together as a family.
l
Offer new foods that are nutritious but not immediately appealing at least 5–10 times.
l
Allow children to selfregulate – to determine when they are hungry and full.
l
Praise children and/or offer a nonfood reward such as sticker when they eat fruits and vegetables or when they try a new food.
l
Apply a moderate amount of restriction and teach that all foods can be part of a healthy diet in the right amounts.
l
Encourage but don’t pressure your children to eat fruits and vegetables.
l
Offer larger portions of vegetables (for specifics, see below) or serve vegetables as a first course.
l
Make fruits and vegetables visually appealing by changing the shape or method of cooking.
Further information
Portion sizes:
l
http://www.nhs.uk/Livewell/5ADAY/Pages/Portionsizes.aspx
l
Ways to encourage and incorporate fruits and vegetables:
l
http://www.nhs.uk/Change4Life/Pages/changeforlifefamilies.aspx
l
References
1. Food Today EU projects supplement 03/2012. Learnings on childhood obesity – sustaining healthy living after IDEFICS:
2. EUFIC Food Today 02/2011. Tastes differ – how taste preferences develop:
http://www.eufic.org/article/en/page/FTARCHIVE/artid/howtastepreferencesdevelop/
3. Gibson EL et al. (2012). A narrative review of psychological and educational strategies applied to young children’s eating behaviours
aimed at reducing obesity risk. Obes Rev 13(1):85–95.
4. Mennella JA & Beauchamp GK. (1996). The early development of human flavor preferences (pp. 83–112). In Capaldi ED. (ed.) Why we
eat what we eat: The psychology of eating. Washington, DC, US: American Psychological Association.
5. Scaglioni S et al. (2011). Determinants of children’s eating behaviour. Am J Clin Nutr 94(suppl):2006s–2011s.
6. EUFIC Food Today 03/2010. Encouraging young children to eat different vegetables:
7. Benton D. (2004). Role of parents in the determination of the food preferences of children and the development of obesity. Int J Obes
28:858–69.
8. Wardle J et al. (2008). Genetic and environmental determinants of children’s food preferences. Br J Nutr 99:S15–S21.
9. AnzmanFrasca et al. (2012). Repeated exposure and associative conditioning promote preschool children’s liking of vegetables. Appetite
58:543–553.
4
Cultural and economic differences influence the type and quality of
school lunches throughout Europe. School lunch makes a substantial
contribution to children’s total energy and nutritional intake. Therefore,
there are efforts amongst governments, schools and parents to
improve the nutritional value of school lunches.
The school lunch provides an important opportunity for learning healthy
habits, and wellbalanced school meals have been linked to improved
concentration in class, better educational outcomes and fewer sick days.
1,2
Given the importance of these meals, what is being done across Europe to
ensure all children have a balanced and enjoyable lunch?
National school meal standards
Many countries in Europe have policies to help schools provide nutritionally
balanced meals which also reflect the general eating culture of each nation.
Often, lunch is eaten in a cafeterialike setting where children receive food
from a central service point (e.g. Finland, Sweden and Italy).
3
In Finland and Sweden, where all school meals are fully funded by the government, lunches follow national dietary guidelines
including the ‘plate model’. An example meal is presented to guide children’s selfservice. Schools in Sweden will be given a
webbased evaluation tool.
4,5
In England, a range of food is offered at lunch time, governed by both foodbased and nutrientbased standards. The
availability of foods high in salt, sugars and fat is restricted (e.g. deepfried foods limited to no more than two portions per
week) and nutrientrich foods are promoted (e.g. at least one portion of fruit and one portion of vegetables available per day).
The food and drink provided in an average school lunch must meet criteria set for 14 different nutrients.
6
In France, each school lunch has to include a main dish (based on meat, fish, eggs, offal or cheese), a side dish, a dairy
product and either a starter or dessert. The nutritional standards regulate how frequently dishes are served in a 20meal cycle.
For example, at least 10 meals in the cycle must be accompanied by cooked vegetables, 10 meals with pulses, starchy foods
or cereals, 8 meals with a fresh fruit dessert. Portion sizes are set by dish and age group.
7
Some countries – including Norway, Denmark, the Netherlands and Belgium – do not have a compulsory system of school
meals. In most countries (except in Finland) schools allow children to bring their own packed lunches.
3
What goes into a balanced packed lunch?
It takes effort to pack a healthy lunch, but the following suggestions provide a helpful guide. Include a variety of foods to help
children get all the nutrients they need.
A balanced packed lunch should include
8
:
l
At least one portion of fruit and one portion of vegetables (a handful, raw or cooked).
l
A portion of starchy food (e.g. bread roll, pitta bread, tortilla wrap, pasta, rice) – wholegrain varieties when possible.
l
A portion of dairy food (e.g. semiskimmed milk, cheese, yoghurt).
l
A portion of protein food: meat (e.g. chicken, beef with fat cut off, or occasionally meat products such as ham and
sausages), fish (oily fish e.g. salmon or sardines at least once every three weeks), eggs, or pulses.
l
A drink of water, fruit juice, or semiskimmed milk.
l
Some snack ideas are unsalted nuts, fresh or dried fruit, or chopped vegetables with cheese or hummus; or a small
packet of crisps or fruitbased cakes and bars can be included from time to time for variety and appeal.
Enjoying lunch
Across Europe, school lunch nutrition standards are the basis for improving nutritional intake of all school children. However,
this will only be successful if pupils like and choose to eat these meals – this is an aspect that has been largely neglected in the
development of school meals until now. Therefore, children are now being involved from the beginning of foodservice planning
including tastetesting. Parents, too, are encouraged to be involved in school meal policies. Changes to the dining environment
can also improve food choices, reduce queuing times, and support social interaction. Importantly, a focus on school meals
should be part of a whole school approach to health promotion.
1,9,10
References
1. Storey HC et al. (2011). A randomized controlled trial of the effect of school food and dining room modifications on
classroom behaviour in secondary school children. Eur J Clin Nutr 65(1):32–8.
2. Belot M & James J. (2011). Healthy school meals and educational outcomes. J Health Econ 30(3):489–504.
3. School Food Trust (2008). The provision of school food in 18 countries:
http://www.childrensfoodtrust.org.uk/assets/researchreports/school_food_in18countries.pdf
4. Finnish National Board of Education (2008). School meals in Finland:
http://www.oph.fi/download/47657_school_meals_in_finland.pdf
5. Livsmedelsverket, Skolmåltider section:
http://www.slv.se/sv/grupp1/Matochnaring/Maltiderivardskola
6. The Education (Nutritional Standards and Requirements for School Food) (England) (Amendment) Regulations 2011 No.
1190:
http://www.legislation.gov.uk/uksi/2011/1190/made
7. Arrêté du 30 septembre 2011 relatif à la qualité nutritionnelle des repas servis dans le cadre de la restauration scolaire
JORF n°0229 du 2 octobre 2011:16575:
http://www.legifrance.gouv.fr/affichTexte.do?
8. School Food Trust, packed lunches section:
http://www.childrensfoodtrust.org.uk/Root/schools/advice/schools/packedlunches
9. Harnoun D et al. (2011). Nutrientbased standards for school lunches complement foodbased standards and improve
School lunch standards in Europe
5
pupils' nutrient intake profile. Br J Nutr 106(4):472–4.
10. Bertin M et al. (2012). School meals in French secondary state schools: do national recommendations lead to healthier
nutrition on offer? Br J Nutr 107(3):416–27.
6
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