Walnuts can play a role in weight management, when consumed as part of a healthy diet.
Research has suggested that health benefits from eating walnuts do not come at the expense of weight gain, according to a review study that looked at 13 research trials.1 Large and longer-term studies are needed to address the effects of walnut consumption on CVD risk and body weight.
A 2016 study found that a diet containing unsaturated fats, such as those found in walnuts and olive oil, may have similar effects on weight loss as compared to a lower fat, higher carbohydrate diet among 245 overweight and obese women.2 Read more details about the promising results.
Furthermore, a study published in 2015 found that one serving of walnuts (1oz) may provide 146 calories, which is 39 calories less or 21 percent fewer, than the 185 calories listed in the USDA Nutrient Database.3 The study takes into account the digestibility of walnut pieces and halves for 18 healthy adults using a bomb calorimetry method rather than the previously used Atwater method. Further research is needed to better understand the results of the study and how this technique for calculating calories could potentially affect the calorie content of other foods.
1Banel DK, Hu FB. Effects of walnut consumption on blood lipids and other cardiovascular risk factors: a meta-analysis and systematic review. Am J Clin Nutr. 2009;90(1):56-63. doi: 10.3945/ajcn.2009.27457.
2Le T, Flatt SW, Rock CL, et al. Effects of Diet Composition and Insulin Resistance Status on Plasma Lipid Levels in a Weight Loss Intervention in Women [published online ahead of print January 25, 2016]. J Am Heart Assoc. doi: 10.1161/JAHA.115.002771.
3Baer DJ, Gebauer SK, Novotny JA. Walnuts Consumed by Healthy Adults Provide Fewer Available Calories than Predicted by the Atwater Factors. J Nutr. 2015;146(1):9-13. doi: 10.3945/jn.115.217372.
10 Ways to Enjoy Walnuts While Watching Your Waistline.