Walnuts can help control appetite, reduce snacking and satiety by improving insulin and glucose blood levels. Together with a balanced healthy sugar free diet, nuts such as walnuts rich in fatty acids can help prevent diabetes. http://onlinelibrary.wiley.com/doi/10.1111/dom.13060/full
Farr OM , Tuccinardi D , Upadhyay J , Oussaada SM , Mantzoros CS . Walnut consumption increases activation of the insula to highly desirable food cues: A randomized, double-blind, placebo-controlled, cross-over fMRI study. Diabetes Obes Metab. 2017;1–5. https://doi.org/10.1111/dom.13060 http://onlinelibrary.wiley.com/doi/10.1111/dom.13060/full