New findings show 60% of farmers are either overweight or obese, compared with 50% of the Irish population.
However, just 27% of the farmers believed they were too heavy.
The ongoing study is being carried out by Teagasc and health professionals from the Waterford Institute of Technology (WIT), Centre for Men's Health, IT Carlow and the UCD Schools of Physiotherapy and Performance Science and Agriculture and Food Science.
There are 366 farmers taking part in the farmers' health study and 86% are male. The most recent findings compares self-reported health behaviours with the overall general population, available from the national Survey on Lifestyle and Attitude to Nutrition (SLAN).
Dr John McNamara, Teagasc health and safety specialist, advised farmers to give more emphasis to their health for quality of life and farm production reasons.
He stated that research from both Ireland and internationally indicates that poor health leads to reduced capacity to undertake farm work and as a consequence reduced farm income. Farmers in poor health are also susceptible to higher levels of injuries.
The study found that 38% of farmers reported one or more health issues in the previous 12 months. Thirty-four per cent reported a physical health complaint and 12% reported mental health issues.
Fifty-nine per cent of farmers had consulted their GP about their health within the last year, which compares to 74% of the general population.
Low back pain was the most prevalent physical complaint, occurring in 28% of farmers. This level is higher than the level for the general population (16%).
Eighty-five per cent of farmers reported drinking alcohol compared to 80% for the Irish population. Nineteen per cent of farmers reported binge drinking (having six or more standard drinks on one occasion) at least once per week compared to 28% of the Irish population.
Aubrey Storey, lecturer in exercise and health science at WIT said the study indicates in particular that farmers should make greater use of healthcare professionals when unwell and to maintain health. It also shows a high level of low back pain which can restrict a farmer's work activity.