The study conducted by Uppsala University reveals that people who eat a lot of polyunsaturated fat gain more muscle than those who eat a lot of saturated fat, reports dailymail.co.uk.
The researchers believe their findings also suggest people who eat lots of polyunsaturated fat are less likely to develop heart disease and type 2 diabetes.
"If the results regarding increased muscle mass following consumption of polyunsaturated fat can be confirmed in our coming studies, it will potentially be interesting for many elderly people, for whom maintaining muscle mass is of great importance in preventing morbidity,' said Ulf Risérus, associate professor at the Department of Public Health and Caring Science and director of the study.
Saturated fat is found in butter, cake, biscuits, fatty cuts of meat, cheese and cream.
Unsaturated fats are found in oily fish, nuts and seeds and olive oil.