TABLE 7.

The strength of the body of evidence supporting the conclusions on the acute effects of breakfast vs. no breakfast, the acute effects of different breakfast types, and the chronic effects of SBPs vs. no SBPs on cognitive test performance in children and adolescents, with the use of the grade definitions for the quality, consistency, quantity, clinical impact, and generalizability of evidence in the Academy of Nutrition and Dietetics Evidence Analysis Manual. Grade definitions: I–Good, II–Moderate, III–Limited, IV–Expert Opinion, and V–Grade Not Assignable (14)¹

Strength of evidence elements	Acute effect of breakfast vs. no breakfast	Acute effect of breakfast type	Chronic effect of SBP vs. no SBP
Quality:Scientific rigor/validity; considers design and execution	Grade II Fair:  Studies of strong design for the question with minor methodologic concerns.	Grade III Limited:  Studies of weak design for answering the question.	Grade III Limited:  Studies of weak design for answering the question.
Consistency:Consistency of findings across studies	Grade II Fair:  Inconsistency among results of studies with strong design.	Grade III Limited:  Unexplained inconsistency among results from different studies.	Grade III Limited:  Unexplained inconsistency among results from different studies.
Quantity:Number of studies; number ofsubjects in studies	Grade I Good:  One to several good quality studies. Large number of subjects studied. Some studies with negative results have sufficiently large sample size for adequate statistical power.	Grade III Limited:  Limited number of studies. Low number of subjects studied, and/or inadequate sample size within studies.	Grade III Limited:  Limited number of studies. Low number of subjects studied, and/or inadequate sample size within studies.
Clinical impact:Importance of studied outcomes; magnitude of effect	Grade II Fair:  Some doubt about the statistical or clinical significance of the effect.	Grade III Limited:  Size of effect is small or lacks statistical and/or clinical significance.	Grade III Limited:  Size of effect is small or lacks statistical and/or clinical significance.
Generalizability:Generalizability to population of interest	Grade III Limited:  Serious doubts about generalizability because of narrow or different study population, intervention.	Grade III Limited:  Serious doubts about generalizability because of narrow or different study population, intervention.	Grade I Good:  Generalizability limited to scope of experience.

¹SBP, school breakfast program.