Stimulants such as methylphenidate are highly effective and recommended by the American Academy of Child and Adolescent Psychiatry. Non-stimulant alternatives are reserved for those not responding to first line therapy.
For children requiring medication, the American Association of Pediatrics recommends methylphenidate for children 4-5 years old, and methylphenidate and other stimulants for children 6-18 years old.
Standard of care from the AACAP and the AAP recommends against treatment interruptions aka drug holidays. Untreated ADHD is to known to have significant long-term consequences including loss of academic performance, social performance, and more aberrant behaviors including substance abuse, teen pregnancies and imprisonment.
Pediatricians report that appetite suppression and weight loss are the most common side effect and lead to dose reduction or medication switching. American Association of Pediatrics suggests dose titration of ADHD medication to achieve maximum benefit while minimizing common side effects such as reduced appetite and weight loss.
Some children may experience a delay in growth in height during the first two years of treatment, but growth proceeds at a normal rate thereafter. In general, height is not affected adversely by stimulants but some cases may prompt monitoring according to the American Academy of Child and Adolescent Psychiatry
One can put excess calories in children in the evenings to mitigate weight loss, but that does not address the core issue of blood glucose during daytime learning. The net result of night feeding may be less weight loss, but also suboptimal attention and learning, which is counter to the rationale for utilizing stimulant medications.
In clinical studies, children with ADHD frequently skipped meals more often than control children, yet they ate more than 5 times per day.