An experiment was conducted to test for the presence of prejudice towards obesity and whether weight controllability beliefs information reduces this prejudice and impacts on a person’s own healthy eating self-efficacy. The experiment randomly allocated 346 participants (49 males) into one of three conditions: controllable contributors toward obesity condition (e.g., information about personal control about diet and exercise); uncontrollable contributors toward obesity condition (e.g., information about genes, factors in society); and a control condition with no information given. Prejudice was present in 81% of the sample. High prejudice was predicted by low self-efficacy for exercise and weight. Weight controllability beliefs information had no significant effect on prejudice levels or exercise or healthy eating self-efficacy levels. Future research directions are discussed.