Background: Being more specific about individual food choices may be advantageous for weight
loss. Including a healthy food (e.g. walnuts) may help to expose effects.
Objective: To examine the impact of including walnuts in diets for weight loss.
Design: Secondary analysis of the HealthTrack lifestyle intervention trial. Overweight and obese
participants were randomized to: usual care (C), interdisciplinary intervention including individualized
dietary advice (I), or interdisciplinary intervention including 30 g walnuts/day (IW).
Changes in body weight, energy intake, intake of key foods, physical activity, and mental health
over three and 12 months were explored.
Results: A total of 293 participants completed the intensive three-month study period, and 175
had data available at 12 months. The IW group achieved the greatest weight loss at three
months. IW reported significant improvements in healthy food choices, and decreased intakes
of discretionary foods/beverages, compared to C. Weight loss remained greatest in IW at 12
Discussion: Significant effects were seen after three months, with the IW group achieving greater
weight loss and more favorable changes in food choices.
Conclusions: Including 30 grams walnuts/day in an individualized diet produced weight loss and
positive changes in food choice.