There have previously been associations between caloric intake and Alzheimer Disease or Cognitive Aging, for example:
https://jamanetwork.com/journals/jamaneurology/fullarticle/7... https://www.pnas.org/doi/10.1073/pnas.0808587106
https://jamanetwork.com/journals/jamaneurology/fullarticle/7... https://www.pnas.org/doi/10.1073/pnas.0808587106
> Conclusion: Higher intake of calories and fats may be associated with higher risk of [Alzheimer Disease] in individuals carrying the apolipoprotein E ϵ4 allele.
> The hazard ratios of [Alzheimer Disease] for the highest quartiles of calorie and fat intake compared with the lowest quartiles in individuals without the apolipoprotein E ϵ4 allele were close to 1 and were not statistically significant.
For the general population, there was no correlation. Identifying specific genetic outliers where there may be a connection is still useful, but far from a general result.