Just over a third of Irish adults are of normal weight, according to official statistics.
While the proportion of men who were overweight and obese dropped slightly since 2017 (from 70% to 66%), overall figures show that 60% of those surveyed were found to be overweight or obese.
Just 37% of adults recorded a normal weight this year.
A survey for the Department of Health also found a significant drop in the number of people smoking.
Health Promotion Minister Catherine Byrne said: “The levels of overweight and obesity in our population remains a great cause for concern.
“While levels appear to be stabilising, there is no room for complacency.
“In recent years Government has introduced evidence-based policies and a range of initiatives and actions to tackle both obesity and physical inactivity, and implementation of these remains a priority.
“This year’s survey shows a small increase in the number of people meeting the guidelines on physical activity, which is encouraging.”
Half of those surveyed were achieving the recommended level of physical activity.
The prevalence of smoking has dropped from 23% in 2015 to 17% in 2019, which means there are now an estimated 165,000 fewer smokers than five years ago.
Plain packaging with health warnings, introduced under a new law last year, was cited by 25% of smokers as a good motivation to quit.
In the last year, 40% of smokers have made an attempt to quit, with health concerns being the prime motivator.
Minister for Health Simon Harris said:” I welcome the findings of this year’s Healthy Ireland Survey and in particular the continued drop in the smoking rate.
“This shows that our multi-pronged approach, with legislation, support for smoking cessation and policies to denormalise smoking in our society, is bearing fruit and we are heading in the right direction to being a tobacco-free Ireland.”
The Healthy Ireland report also found that the level of smoking in Ireland has dropped from 20% to 17% of the population.
82,500 people gave up smoking in Ireland in the past year.
The number of people who gave up was highest among those aged between 25 and 34, unemployed people and those living in deprived areas.