Table 4.

Why a ketogenic diet is not the best diet for ASD.

Most Common Side Effects	References
The KD can be difficult to maintain, especially in children with limited food preferences. It is important to have a plan in place to ensure that the child is able to stick to the diet. ASD patients also consume fewer foods and exhibit more feeding problems and diverse eating behaviors (selective intake, food refusal, food aversion, and atypical eating). Some foods are refused due to presentation or the need to use certain utensils. In a study by Albers et al. [68] 73% of the respondents rated adherence to the KD as more difficult, compared with age-matched controls, whereas only 26% of the subjects did not report such difficulties. These results confirm that the administration of a KD to ASD children is difficult.	Li et al. [69] Mayes & Zickgraf [70]
The sensory abnormalities commonly associated with ASD can influence the administration of and adherence to the KD. Parents reported that children with ASD were significantly more averse to food textures (p < 0.0001), in particular foods with a slimy and creamy texture. According to the authors, taste preferences and consistent food routines are important or very important determinants of the successful implementation of the KD.	Albers et al. [68] Balasco et al. [71] Cermak et al. [72]
Taste, smell, and texture hypersensitivities/aversions were regarded as the key difficulties in the implementation of a KD	Albers et al. [68]
Nutrient Deficiencies: The KD is very restrictive, and it may not provide growing children with the necessary nutrients. In children, the KD may suppress physical development and cause height deceleration. Parents should work with healthcare providers or dietitians to eliminate the risk of nutritional deficits.	Spulber et al. [73]
Possible Side-Effects: Some children may experience side effects from the KD, such as constipation, nausea, and vomiting. During the initial phase of the diet, common side effects also include hypoglycemia, metabolic acidosis, and refusal to eat.	Neal et al. [74] Newmaster et al. [75]