Infants and toddlers should not be given soda, chocolate milk or other sweetened drinks, according to strict new guidelines.

A panel of scientists issued new nutritional guidelines for children on Wednesday, describing in detail what they should be allowed to drink in the first years of life. The recommendations, among the most comprehensive and restrictive to date, may startle some parents.

Babies should receive only breast milk or formula, the panel said. Water may be added to the diet at 6 months; infants receiving formula may be switched to cow’s milk at 12 months. For the first five years, children should drink mostly milk and water, according to the guidelines.