For my youngest child I had to cut out a lot of the juices, especially Red. Seemed like he was allergic to the dye in them, made him hyper. Juices do have alot of sugar. Other well known additives that cause an allergic reaction include, cyclamate, saccharin, aspartame, sulfites, yellow #5 dye, and blue lake dye. In children it can manifest as hyperness. Aspartame, derived from phenylalanine, can cross the blood brain barrier, and cause wakefulness. The "allergic response" isn't just a runny nose. Other responses include racing heart, headaches, hyperness, acne, and mood changes. Which applies to Adults as well.
Switching to milk is a good idea, as it contains Tryptophan, a natural substance that produces calm, as well as calcium.
During the day, fresh air,sunshine, and physical activity. At night, turning the tv down, turning off bright lights,warm bath, and keeping the "bedtime routine" the same also helps.
With my oldest, when the MASH theme song came on, he knew it was time for bed. He'd even try to change the channel, thinking if I didn't hear it, it wouldn't be time.
Good luck, it takes time and patience, remain consistent, and it will change.