I would 100% agree with this claim. It is no surprise that young girls' body image is being affected by social media, as social media (whether knowingly or not) has contributed greatly to how we view ourselves and with societal pressure and beauty standards being forced upon young girls. The National Library of Medicine, or NIH, states that "This has resulted in increasing body dissatisfaction and negative mental health outcomes, as adolescents seek validation through likes and comments," talking specifically about the effects directly related to Instagram and TikTok. It goes further onto state how the rise in body dysmorphia and eating disorders in young girls is directly related to social media on another page, with the median age of an eating disorder starting at 12 years old for young girls. With the unchecked age restrictions on social media cites, as many claim you must be at least 13 to be on the websites, it is easy to log onto a cite, lie about your age, and be exposed to many things that can be harmful to pre-teenagers, but especially young girls, as their brains are not fully developed and ready to process all that social media has to offer.
From the NIH, an unbiased government agency, we can trust this source to give us valuable feedback as well as information. The keywords and the language used in these government websites is very neutral, only displaying hypotheses and factual evidence. Because of the government's relationship with China, there is a chance that anything relating to the United States government will be slightly in favor of TikTok, as it is a Chinese company, but after reading through both pages they both seem very reliable and not politically biased one way or another
NIH Social Media and Adolescents Page:
The Impact of Social Media on Adolescent Body Image: A Comprehensive Review - PMC
NIH Eating Disorders and Social Media Page:
Social media use among adolescents with eating disorders: a double-edged sword - PMC