That is a finding from University of Otago research, based on a study of 70 Dunedin infants and toddlers, and their parents.
The study, with researchers from New Zealand, Australia and the United States, followed other research showing obesity prejudice and discrimination were increasing.
Prof Ted Ruffman, of Otago's psychology department, said anti-fat prejudice was ''associated with social isolation, depression, psychiatric symptoms, low self-esteem and poor body image''.
He emphasised the research findings were not meant to be a ''mother-blaming exercise'', but it indicated ''how early children begin to absorb and display the attitudes of those around them''.
Mothers tended to be the primary caregivers and were ''just reflecting wider societal attitudes''.
Previous research indicated anti-fat prejudice could be seen in preschool children aged slightly more than 3 and was well-established in 5- to 10-year-olds.
But research by Prof Ruffman and his team suggested these attitudes had even earlier beginnings, apparent from the age of about 2 years 8 months.
''The surprising thing is that the link is so early,'' he said in an interview.
The team showed 70 infants and toddlers pairs of photos of people-one in which the person was obese, and the other in a normal weight range. Researchers also used questionnaires to gauge the mother's attitude to obesity.
''What we found is that younger infants, around 11 months of age, preferred to look at obese figures, whereas the older toddler group, around 32 months old, preferred to look at average-sized figures,'' Prof Ruffman said.
And that preference was ''strongly related to maternal anti-fat prejudice''.
There was a high correlation: the more the mother had expressed anti-fat attitudes in the questionnaire, the more the older toddlers would ''look away from the obese figure towards the normal weight one''.
Adding to the distinctiveness of the study was that researchers had also considered other potential factors, such as parental body mass index (BMI) - a measurement derived from weight and height - as well as education, and the amount of children's television viewing.
But these were found to be unrelated to the sort of figure the child preferred to look at.
These were clear findings, just published in the Journal of Experimental Child Psychology, and he believed they would interest parents.
Study co-author Associate Prof Kerry O'Brien, of Monash University, said weight-based prejudice was ''causing significant social, psychological, and physical harms'' to those stigmatised.
