May 10, 2023. The Journal of Nutritional Science has recently published a study that showed macadamia consumption does not lead to weight gain and may have other positive benefits on cardiometabolic risk factors for overweight and obese adults.
The MAC (Macadamia Nut Effects on Adiposity and Cardiovascular Risk Factors) study was a randomized crossover trial led by Dr. Joan Sabaté and conducted by researchers from Loma Linda University in the USA that aimed to analyze how macadamia consumption affects body weight, waist circumference and other cardiometabolic risk factors. The study consisted of 35 individuals aged from 40 to 75 and with a body mass index between 25 and 39, a waist circumference greater than 102 cm for men and 89 cm for women, and one additional cardiometabolic risk factor.
Participants were randomly assigned to two groups. One group was instructed to consume macadamia nuts daily for a total of 8 weeks, representing 15% of their total energy. Then, following a 2-week “wash-out” period, they returned to their normal diet for another 8 weeks. The other group consumed their normal diet during the first phase and switched to the macadamia diet during the second phase. The researchers then assessed the cardiometabolic risk factors using statistical analyses.
The results showed that consumption of macadamias did not lead to changes in waist circumference, body mass or percentage of body fat. Moreover, compared to the control diet, consumption of macadamias led to lower total cholesterol, LDL (“bad”) cholesterol, and reductions in average weight and body mass index, although these were not statistically significant.
Lead researcher Dr. Joan Sabaté discussed the study by saying, “Weight gain is a major public health problem and an issue of concern for many individuals. Our macadamia study with free-living participants showed that including one to two servings of macadamias to their daily diets does not result in weight gain.”
The study was funded by the global macadamia industry. The call was coordinated by the International Nut and Dried Fruit Council (INC) with the support of the INC World Forum for Nutrition Research and Dissemination.
Jones, J., Sabaté, J., Heskey, C., Oda, K., Miles, F., & Rajaram, S. (2023). Macadamia nut effects on cardiometabolic risk factors: A randomised trial. Journal of Nutritional Science, 12, E55.