Firth J, Stubbs B, Teasdale SB, Ward PB, Veronese N, Shivappa N, Hebert JR, Berk M, Yung AR, Sarris J (2018) World Psychiatry. 2018 Oct; 17(3): 365–367. 2018 Sep 7. doi: 10.1002/wps.20571
Overall, this population‐scale analysis of nutritional intake confirms that people with SMIs have higher intakes of obesogenic nutrients and more inflammatory diets than the general population. Whereas dietary interventions for SMIs often focus exclusively on over‐consumption of obesogenic, pro‐inflammatory foods, this study shows that further consideration should be given to increasing consumption of nutrient‐dense foods that are known to reduce systemic inflammation.
In terms of both total caloric intake and excess obesogenic nutrients, the worst dietary patterns were observed among people with schizophrenia. This is a notable finding, as these individuals also have significantly higher rates of metabolic disorders and greater premature mortality than individuals with other classes of SMI, indicating that diet could be a key factor influencing these outcomes.
Indeed, dynamic weight change algorithms predict that each 100 kj of excess energy intake per day will eventually lead to at least 1 kg increase in body weight. Thus, the 553 kj (132 calories) per day excess observed in the schizophrenia sample suggests that dietary differences alone can account for 5‐6 kg of the increased body weight observed in this population. Not only does excess caloric, carbohydrate and fat intake increase inflammation, but the concomitant increase in adipose tissue also enhances chronic, systemic inflammation.The degree to which the heightened systemic inflammation observed in SMIs is attributable to dietary factors needs to be clarified. Sufficiently sized cohort studies, using detailed dietary and psychiatric data alongside biomarkers of inflammation, can provide new insights into of the role of diet in SMIs. Future work should also aim to establish the extent to which heightened dietary inflammation in SMIs independently contributes to the poor physical, psychological and neurocognitive outcomes observed in these populations, which represent a significant public health challenge.