A study of two to six-year-olds found that those who spend just an hour a day extra in front of the TV are much fatter than those who do not.
But scientists believe the cause is food intake rather than inactivity, and that the children may be stimulated to eat by what they are watching.
Said Dr Diane Jackson, from the university's Rowett Institute of Nutrition and Health: 'The results showed a clear positive link between how much time per day the children spent watching TV and how fat they were.
'Given that TV programming for young children has increased in recent years, the relationship between TV viewing and diet may be a promising target for future obesity interventions.'
The findings are published in the American Journal of Clinical Nutrition.
Related article: One in four children in reception class is overweight or obese
Need to keep ahead of nursing news and clinical developments? Let us help. Get a comprehensive round-up delivered free to your inbox every day. Simply click here, log in and select 'Daily news alert'