The participants of the study were randomly assigned to a walnut group (n = 183) or control group (n = 173). Volunteers in the walnut group received packaged walnuts (between 28-56 g/day), providing ~15% of their estimated daily energy needs, to incorporate into their habitual diet, while those in the control group abstained from walnuts. After two years of follow-up, results showed that body weight decreased significantly. Participants in the walnut group lost an average of 0.4 kg.
In conclusion, findings showed that walnuts could be incorporated into the daily diet of healthy older adults without concern for adverse effects on body weight.
Bitok, E., Rajaram, S., Jaceldo-Siegl, K., Oda, K., Sala-Vila, A., Serra-Mir, M., … & Sabaté, J. (2018). Effects of Long-Term Walnut Supplementation on Body Weight in Free-Living Elderly: Results of a Randomized Controlled Trial. Nutrients, 10(9), 1317.