There has been an increase in under 14-year-olds treated for eating disorders at Sussex Partnership Trust.
The trust has treated more than twice the number of 11-14 year olds - 41 patients compared to 18 the year before.
The number of patients treated who are under 11 years old has also increased – from just one patient to three in 2013-14.
Those treated aged between 15 and 17 more than doubled, from 48 in 2012-13 to 118 last year.
A spokeswoman for the trust said: “We know that young children may not be identified as having an eating disorder early on in their condition as a physical cause for weight loss may be considered first. This means that by the time an eating disorder is identified and the child is referred to us they are much more ill and need more specialist help.”
She added: “Given the complexity of diagnosing severe eating disorders we cannot pinpoint one reason for the increase of referrals for younger children but it may be there is increased in awareness of eating disorders in the very young amongst GPs and other health professionals.”