Table 2.
Characteristics of the included studies.
| Study (Year) | Country | Study Design | Population Characteristics | Outcome | Intervention Characteristics | |||
|---|---|---|---|---|---|---|---|---|
| Age | Sample Size (n) | BMI (Mean ± SD) |
Cognition Test | Cognition Domain | ||||
| Benton et al., 2007 [27] | UK | Randomized crossover trial | 6.8 (5.9–7.7) | 19 | NR | (1) Recall of Objects test of the British Ability Scale (2) Paradigm of Shakow |
(1) Memory (2) Sustained Attention |
- High GI GI: 62.8; GL: 39.0; Kcal: 305 - Medium GI GI: 50; GL: 5.9; Kcal: 299 - Low GI GI: 46; GL: 14.8; Kcal: 284 |
| Brindal et al., 2012 [28] | Australia | Randomized crossover trial | 11.6 ± 0.7 | 39 | 18.9 ± 3.0 | (1) Reaction time response test (2) Attention switching test (3) Finding ‘A’s task (4) Rey Auditory Verbal Learning Test (5) Weschler Intelligence Scale for Children: Digitspan (6) Windows-based program |
(1) Speed of processing (2) Attention switching (3) Perceptual speed (4) Short-term memory (5) Working memory (6) Inspection time |
- High GI GI: 67; GL: 33; Kcal: 314 - Medium GI GI: 54; GL: 24; Kcal: 312 - Low GI GI: 48; GL: 18; Kcal: 315 |
| Cooper et al., 2012 [29] | UK | Randomized crossover trial | 12.8 ± 0.4 | 41 | 20.5 ± 3.3 | (1) Stroop test (2) Sternberg paradigm (3) Flanker test |
(1) Inhibition (2) Working memory (3) Inhibition |
- High GI GI: 72; GL: 54; Kcal: 422 - Low GI GI: 48; GL: 36; Kcal: 420 - No Breakfast |
| Ingwersen et al., 2007 [30] | UK | Randomized crossover trial | 9.3 (6.8–11.7) | 64 | 17.5 | (1) Cognitive Drug Research (CDR) Computerized Assessment Battery | (1) Speed attention, (2) Speed memory, (3) Accuracy of attention, (4) Secondary memory, (5) Working memory |
- High GI GI: 77; GL: -; Kcal: 133 - Low GI GI: 42; GL: -; Kcal: 98 |
| Mahoney et al., 2005 (a) [31] | USA | Non-RCT | 9.0–11.0 | 30 | 21.0 ± 6.1 | (1) Self-developed spatial map test (2) Digit Span Test (3) Rey Complex Figure Test (RCFT) (4) Continuous Performance Test (CPT) (5) Self-developed prose memory test |
(1) Spatial Recall, Learning (2) Immediate Recall, Immediate Attention, Working Memory (3) Visual–Spatial Perception (4) Visual Attention, Vigilance, Auditory Attention (5) Prose Memory |
- Ready-to-eat (high GI) GI: -; GL: -; Kcal: 200 - Oatmeal (low GI) GI: -; GL: -; Kcal: 200 - No breakfast |
| Mahoney et al., 2005 (b) [31] | USA | Non-RCT | 6.0–8.0 | 30 | 17.7 ± 4.8 | (1) Self-developed spatial map test (2) Digit Span Test; (3) Rey Complex Figure Test (RCFT) (4) Continuous Performance Test (CPT) (5) Self-developed prose memory test |
(1) Spatial Recall, Learning (2) Immediate Recall, Immediate Attention, Working Memory (3) Visual–Spatial Perception (4) Visual Attention, Vigilance Auditory Attention (5) Prose Memory |
- Ready-to-eat (high GI) GI: -; GL: -; Kcal: 200 - Oatmeal (low GI) GI: -; GL: -; Kcal: 200 - No breakfast |
| Micha et al., 2010 [32] | UK | Pilot study | 13.0 ± 0.8 | 60 | 20.7 ± 4.6 | (1) Word Generation Task (2) Immediate Word Recall (3) Stroop Test (4) Matrices (5) Number Search (6) Serial Sevens (7) Delayed Word Recall |
(1) Verbal Fluency (2) Immediate Verbal Recall (3) Alternating Attention, Selective Attention, Impulsivity (4) Visual Reasoning, Nonverbal Intelligence (5) Visual Attention (6) Sustained Attention (7) Delayed Verbal Recall |
- High GL and high GI GI: 68; GL: 44; Kcal: 378.7 - Low GL and high GI GI: 64; GL: 23; Kcal: 240.3 - High GL and low GI GI: 53; GL: 43; Kcal: 502.2 - Low GL and low GI GI: 58; GL: 31; Kcal: 272.0 |
| Micha et al., 2011 [33] | UK | Randomized crossover trial | 12.6 ± 0.9 | 74 | 19.3 ± 3.4 | (1) Word Generation Task (2) Immediate Word Recall (3) Stroop Test (4) Matrices (5) Number Search (6) Serial Sevens (7) Delayed Word Recall |
(1) Verbal Fluency (2) Immediate Verbal Recall (3) Alternating Attention, Selective Attention, Impulsivity (4) Visual Reasoning, Nonverbal Intelligence (5) Visual Attention (6) Sustained Attention (7) Delayed Verbal Recall |
- High GL and high GI GI: 61; GL: 55; Kcal: 468.6 - Low GL and high GI GI: 61; GL: 28; Kcal: 275.6 - High GL and low GI GI: 48; GL: 41; Kcal: 469.7 - Low GL and low GI GI: 48; GL: 21; Kcal: 281.2 |
| Smith and Foster, 2008 [34] | Australia | RCT | 15.7 ± 0.9 | 38 | 22.0 ± 3.0 | (1) California Verbal Learning | (1) Verbal Recall | - High GI GI: 77; GL: -; Kcal: 172 - Low GI GI: 30; GL: -; Kcal: 158 |
BMI: body mass index; GI: glycemic index; GL: glycemic load; RCT: randomized control trial.