The study also found a significantly higher rate of smoking in this group
People who work shifts in Ireland are skipping meals and not getting enough sleep.
That is according to a new report from SafeFood, which also found that in some employment sectors, one-in-three shift workers were smokers - a rate significantly higher than those in the general population.
The report says more than two-in-three shift workers reported skipping meals on work days, and almost eight-in-ten reported getting insufficient sleep.
The study also found that lack of breaks, shift patterns, poor availability of food and tiredness due to long working hours were the most common barriers to leading a healthier lifestyle.
Research leader and associate professor at University College Dublin (UCD), Dr Clare Corish, said: "For this research we looked at existing studies in this area as well as surveying more than 1,000 people to better understand the factors that influence their food and related lifestyle habits while working shift hours.
"What's noticeable from the research is how skipping meals, inadequate physical activity and insufficient sleep are commonly noted by shift workers as behaviours that impact upon them.
"We're also seeing how the different workplace sectors play a role in those behaviours and how complex that can be - health and social care workers have poorer access to healthier food options and often an erratic, stressful work schedule - but in general have healthier patterns of food consumption and lower rates of smoking.
"By comparison, the manufacturing sector has more defined work patterns and breaks and are more likely to have workplace facilities available but higher rates of smoking."
Gender and age were also identified as being influencing factors: men reported poorer eating habits than women and were more likely to report being overweight.
Younger shift workers also reported poorer dietary habits and higher alcohol consumption rates than older workers - while older workers reported poorer sleep patterns and lower levels of physical activity.
Welcoming the report, SafeFood CEO Ray Dolan added: "It has been long assumed that shift work has a negative impact on people’s health and increases the risk of chronic diseases like heart disease and cancer.
"With the publication of this research, we’re beginning to address an important gap in our knowledge of both the barriers and potential public health interventions to improving the food and related lifestyle habits of people working shifts."
While Dr Cliodhna Foley-Nolan, director of health and nutrition at SafeFood, said the findings highlight that a number of targeted approaches are required to address the issues raised.
"It’s clear that we need to support younger and newer shift workers in order to enable them to adapt to shift hours.
"This will help create healthier habits they will hopefully take with them through their career. It is acknowledged that healthy eating advice can’t follow a ‘one-size-fits-all’ approach and needs to account for the specific environment of shift workers.
"Key issues are providing both time and facilities to eat healthily during a work shift and promoting healthy physical activity and sleep habits".