Several studies comparing isocaloric diets have shown an equivalent or greater weight loss efficacy with structured meal replacement plans, compared to reduced calorie diet treatments. One or two daily vitamin- and mineral-fortified meal replacements, supplemented with self-selected meals and snacks, may be a successful weight loss and weight maintenance strategy for overweight and obese adults who have difficulty with self-selection of food and portion control.

• 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.