*4.3. Glycaemic Control*

Chen et al. [31] did not find any significant effect with respect to change in glycated haemoglobin (HbA1c) and fasting serum glucose values in the almond-based and control diets. However, in the study by Cohen et al. [32], there was a significant reduction (*p* = 0.045) in HbA1c in the almond-based diet group compared with control group. Ren et al. [14] also showed that almond-based LCD may be effective in modulating glycometabolism in patients with diabetes.

Bodnaruc et al. [30] noted that the almond-based meal was associated with lower postprandial glucose. According to Hou et al. [6], while the almond-based diet did improve fasting, postprandial blood glucose, and glycated haemoglobin in patients with type 2 diabetes, these were not significantly different from the control group. Li et al. [33] observed that including almonds in a healthy diet led to significant improvement (*p* < 0.05) in glycaemic control, while Lovejoy et al. [35] showed that an almond-enriched diet had no significant effect (*p* > 0.05) on glycaemia in patients with diabetes.

With respect to the meta-analysis, the results of the effects of almonds on glucose control are shown in Figure 3a–d. Six studies each contributed data for the HbA1c analysis (almond group (gp), *n* = 115; control gp, *n* = 114) (Figure 3a; sub-group analysis, Figure 3b) and fasting blood glucose analysis (almond gp, *n* = 113; control gp, *n* = 111) (Figure 3c). The almond-based diet group experienced a significant reduction (*p* < 0.001) in HbA1c levels compared to the control group with a mean difference of −0.52 (95% CI: −0.58, −0.46). Regarding the 2-hour postprandial blood glucose levels, two studies contributed to the data analysis (almond gp, *n* = 44; control gp, *n* = 41) (Figure 3d). The levels of fasting blood glucose and 2-hour postprandial blood glucose were lower in the almond group compared to the control group, although the differences were not significant (*p* > 0.05). The mean differences were −0.03 (95% CI: −0.18, 0.11) for fasting blood glucose and −0.15 (95% CI: −0.44, 0.13) for postprandial blood glucose.

The sensitivity analysis conducted by removing studies one by one from the metaanalysis did not change the results in relation to HbA1c (*p* < 0.05), fasting blood glucose (*p* > 0.05), and 2 h postprandial blood glucose (*p* > 0.05). The sub-group analysis for HbA1c showed that, although there was a significant difference (*p* < 0.001) between the almond group and control with respect to the meta-analysis of the randomised parallel studies, the differences were not significant (*p* = 0.25) in relation to the cross-over studies (Figure 3b).

#### *4.4. Inflammatory Markers*

The study by Liu et al. [34] observed that the addition of almonds into a healthy diet could ameliorate inflammation and oxidative stress in patients with type 2 diabetes. Similarly, Sweazea et al. [36] noted that the daily consumption of almonds in the absence of other dietary or physical activity activities could be an effective approach in reducing inflammation in patients with type 2 diabetes.

The meta-analyses of the effects of almonds on inflammatory markers are shown in Figure 4a,b. Three studies contributed data for the C-reactive protein analysis (almond gp, *n* = 63; control gp, *n* = 63) (Figure 4a) and two studies for tumour necrosis factor- α (TNF- α) analysis (almond gp, *n* = 30; control gp, *n* = 31) (Figure 4b). The levels of C-reactive protein and TNF- α were lower in the almond group compared to the control group. However, the differences between the two groups were not significant (*p* > 0.05), with mean differences of −0.54 (95% CI: −1.61, 0.53) for C-reactive protein and −16.67 (95% CI: −53.25, 19.91) for TNF- α respectively. The results did not change between the almond group and control group (*p* > 0.05) with respect to C-reactive protein and TNF- α following sensitivity tests.
