Predictors of sweet and fatty blood
The Low-carb, Low-fat, Keto, Vegetarian, Carnivore, and so much more, which diet is better for me? and why? These questions are on the mind of many, actively debated amongst the experts, with no consensus on the horizon. Personalized nutrition companies strive to address this important need.
ZOE is a leading personalized nutrition company that relies on the idea that “everybody’s response to food is unique”. Their recent study  shows that blood sweetness and fattiness (i.e. glucose and triglyceride levels) after a meal are (a) highly variable amongst individuals, and (b) predictable given person-specific factors and meal macronutrients. Best predictors of blood sweetness were the meal macronutrients, genetics and lifestyle factors such as sleep and physical activity. The best predictors of blood fattiness however were fasting blood assays. The gut microbiome was also a predictive factor for blood sweetness and fattiness, but to a lesser extent.
A prior study  related to the DAYTWO company, however, emphasized the importance of gut microbiome for predicting blood sweetness after the meal. They achived similar accuracy for predicting blood sweetness after the meal, however they used higher resolution microbiome profiling (shotgun metagenomics) and didn’t consider inter-individual genetic variations. Unfrotunately the relative value of individual factors for the prediction task was not reported in this study.
Although both studies are very interesting, their results are not entierly inline with each other. They also do not report the minimum set of factors needed for the peak prediction performane. Given that each study employs a different methodology, performing a consistent data analysis on their combined data is needed. It will also be very valuable for consumers to know the extent to which the recommendations from these personalized nutrition companies are consistent with each other and with the general advice from nutritionists.
 Berry, S.E., Valdes, A.M., Drew, D.A., Asnicar, F., Mazidi, M., Wolf, J., Capdevila, J., Hadjigeorgiou, G., Davies, R., Al Khatib, H. and Bonnett, C., 2020. Human postprandial responses to food and potential for precision nutrition. Nature Medicine, pp.1-10. doi: 10.1038/s41591-020-0934-0.
 Zeevi, D., Korem, T., Zmora, N., Israeli, D., Rothschild, D., Weinberger, A., Ben-Yacov, O., Lador, D., Avnit-Sagi, T., Lotan-Pompan, M. and Suez, J., 2015. Personalized nutrition by prediction of glycemic responses. Cell, 163(5), pp.1079-1094. doi: 10.1016/j.cell.2015.11.001.