Absolutely not. The idea that "all Mexican men like fat girls" is a reductive stereotype with no basis in fact. Attraction is deeply individual, shaped by personal experience, culture, media, psychology, and biology—not nationality.
Why this stereotype exists:
Reality: Mexican men—like men everywhere—have diverse preferences. Studies on body image in Mexico show a range of ideals, influenced by socioeconomic status, region, age, and exposure to global media. Obesity is a major public health concern in Mexico; it is not universally celebrated.
Reducing any group to a single preference is dehumanizing. Respect individuals, not stereotypes.