Using a reduced-calorie diet (over 1,200-DRI kcal per day) in the acute treatment phase of adolescent obesity is generally effective for short-term improvement in weight status. However, without continuing intervention, weight is regained.

All the studies reviewed had treatment programs lasting less than one year (three weeks to nine months) and evidence on longer-term treatment trials was not available.

• Grade I means there is Good/Strong evidence supporting the statement;
• Grade II is Fair;
• Grade III is Limited/Weak;
• Grade IV is Expert Opinion Only;
• Grade V is Not Assignable.
• High (A) means we are very confident that the true effect lies close to that of the estimate of the effect;
• Moderate (B) means we are moderately confident in the effect estimate;
• Low (C) means our confidence in the effect estimate is limited;
• Very Low (D) means we have very little confidence in the effect estimate.
• Ungraded means a grade is not assignable.