Eating just half a serving of nuts, including walnuts, every day, could stop you gaining weight as you get older and decrease the risk obesity, research suggests.

The research, by Harvard University, was published in the online journal BMJ Nutrition, Presentation and Health. For more than 20 years, over 250,000 people were asked to state every four years their weight and how often they had eaten nuts over the preceding year.

The study found that increases in nut consumption of just half a serving per day (14g), was associated with less long term weight gain and a lower risk of becoming obese. The study also looked at the effects of different nuts on weight gain and found that eating 14g of walnuts specifically, resulted in twice the weight loss over a 4 year period, compared to other tree nuts (-0.36 kg  v -0.15 kg) and a 15% lower risk of obesity.

The study was partly funded by the California Walnut Commission. The California Walnut Commission had no roles in study design, data collection and interpretation and decision on manuscript publication. Full details on the study can be found here:

Incorporating a handful (approx. 30g) of California Walnuts into meals or eating them as a snack is a simple way to add important nutrients to your diet. Walnuts are the only tree nut to contain a significant amount of the plant-based omega-3, alpha-linolenic acid (ALA), 2.7g/ 30g and a handful of walnuts also offers 4.4g of protein and 1.4g of fibre.1

[1] Food Standards Agency (2002), McCance & Widdowson’s The Composition of Foods, Seventh summary edition. Cambridge: Royal Society of Chemistry