Pictured above: A beautifully presented box of Wedgewood Macalettes – the brand has a hugely popular range using macadamia nuts as an ingredient which includes ice cream and biscuits.

The MAC (Macadamia Nut Effects on Adiposity and Cardiovascular Risk Factors) study was a randomised crossover trial led by Dr Joan Sabaté and conducted by researchers from Loma Linda University in the USA that aimed to analyse how macadamia consumption affects body weight, waist circumference and other cardiometabolic risk factors.

The study consisted of 35 individuals aged 40 to 75 and with a body mass index of between 25cm and 39cm, a waist circumference greater than 102cm for men and 89cm for women, and one additional cardiometabolic risk factor.

Participants were randomly assigned to two groups. One was instructed to consume macadamia nuts daily for a total of eight weeks, representing 15% of their total energy. Then, after a two-week “wash-out” period, they returned to their normal diet for another eight 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 with 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.

Sabaté said, “Weight gain is a major public health problem and an issue of concern for many individuals. Our study showed that including one to two servings of macadamias in daily diets will not result in weight gain.”

The study was funded by the global macadamia industry and coordinated by the International Nut and Dried Fruit Council (INC) with the support of the INC World Forum for Nutrition Research and Dissemination.