Evening work shifts: why it’s better not to eat

Evening work shifts: why it's better not to eat


Carrying out professions which contemplate an organization in shifts, and therefore which also include night shifts , could have a negative effect on the body if meals are eaten in the dark hours. The optimal solution would be to divide meals during the day in any case in order not to develop disorders related to the biological clock, diabetes , cardiovascular problems but also anxiety and depression , even if this division of meals is not always practicable. A research entitled “Daytime eating prevents mood vulnerability in night work” published in the journal TheProceedings of the National Academy of Sciences reveals the consequences of eating during the evening shift.


Why not eat during the evening shifts

  • increases the risk of diabetes
  • increased risk of cardiovascular disease
  • 24-hour biological clock shift
  • increased anxiety and depression
  • increased blood sugar
  • cortisol increase
  • increased sleep disturbances
  • weight gain
  • digestive difficulties
  • gastrointestinal disorders
  • chronic fatigue
  • oromal dysfunction (in women)
  • menstrual imbalance

The Study on night shifts and meals

The researchers at Brigham and Women’s Hospital in Boston who worked on the study involved 19 healthy adults , males and females, as a research sample, dividing them completely randomly into two different experimental groups. For both, diet, physical activity , posture , sleep duration  , light conditions were virtually identical. The night work shift is also the same, recreated in the laboratory by acting on the biological clock of the research participants, through a shift in the circadian rhythm (sleep-wake cycle / fasting – nutrition and the external light-dark cycle). The only difference was the timing of meals: the subjects of one group ate meals both during the day and at night, while those of the second group only ate during the day. The study with the laboratory experiment lasted 4 days.

Sleep-wake rhythms: what are they?

  • The  circadian or nicthemeral rhythms (nict- night, -emera day) whose frequency is about one cycle every 24 hours (in fact between 20 and 28 hours): wake-sleep alternation, nicthemeral cycle of the central temperature.
  • The infradian rhythms, whose period is more than 28 hours: the annual, seasonal, monthly rhythms.
  • Ultradian rhythms whose period is less than 20 hours.

Anxiety and depression among the consequences

The results highlighted by the group of researchers showed that anxiety (16.1%) and depression (26.2%) increased in the group of people who ate meals during the day and at night. The greater the imbalance of the biological clock, the more anxious states increased . These changes were not found among participants in the second group who ate meals only during daytime hours. The consequence of this experiment highlights how the risk of developing psychiatric diseases is higher in subjects employed in night work, significantly affecting the quality of life of the workers themselves. The desynchronization of the circadian rhythm inevitably causes disturbance of the biological clock.

Shift Worker Syndrome

There is clear evidence that work organized in shifts has a significant impact on the health and quality of life of the worker (but also of any family members who have to “adjust” their habits according to the work shifts) due to the alteration of processes natural “misalignment” of the sleep-wake cycle due to the rhythms imposed by life commitments, known in medical literature as shift work sleep disorder. This can commonly involve:

  • tiredness ,
  • poor job performance,
  • sleep disorders,
  • difficulty falling asleep or waking up,
  • increases the risk of mental disorders and psychosocial distress,
  • depression,
  • anxiety,
  • work stress ,
  • worse quality of life,
  • food disorders


Who suffers the most. Shift worker syndrome is  more frequent in subjects who work at particular times, especially during the night between 10pm and 6am , such as medical and paramedical personnel, law enforcement officers, tertiary sector workers, night porters.

Increased sugar and mood disorders

Not only the increase in depression and anxiety would be the consequence of meals eaten at night in evening shift workers, but also various health problems affecting the cardiovascular and endocrine systems . For example, several studies on the subject have shown that consuming meals at night significantly increases the level of sugar in the blood which, in turn, can cause the onset of diabetes, metabolic, sleep, endocrine disorders and weight gain , as well as depression. and mood swings . Furthermore, the consequences are even worse if the meals eaten in the dark are rich in simple sugars ,saturated fat and lack of fiber . Following a healthy and balanced diet, and consuming meals only during the day, contributes to the improvement of the general state of health of night workers but also for those who often travel on business trips (jet lag) or for all those who suffer of circadian rhythm disorders and sleep disorders.


If you have a sedentary job , you need to move at least 30-40 minutes a day to compensate.



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