Eating a diet rich in walnuts may help you shed those extra kilos and improve your cholesterol level, a new study has claimed.
A diet containing unsaturated fats, such as those found in walnuts and olive oil, has similar weight loss effects as a lower fat, higher-carbohydrate diet, researchers said.
The study also showed that a diet containing walnuts, which are primarily comprised of polyunsaturated fats, positively impacts heart health markers, such as cholesterol.
"One of the surprising findings of this study was that even though walnuts are higher in fat and calories, the walnut-rich diet was associated with the same degree of weight loss as a lower fat diet," said Cheryl Rock of the University of California, San Diego, who led the study.
"Considering the results of this study, as well as previous walnut research on heart health and weight, there's something to be said for eating a handful of walnuts a day," said Rock.
The researchers studied 245 overweight and obese women (22-72 years old) enrolled in a one-year behavioural weight loss intervention.
Participants were randomly assigned to three different diets - a lower fat and higher carbohydrate diet, a lower carbohydrate and higher fat diet, or a walnut-rich, higher fat and lower carbohydrate diet.
Those prescribed a walnut-rich diet consumed 1.5 ounces per day. Data from the first six months of the intervention showed that the average weight loss was nearly eight per cent of initial weight for all groups.
The walnut-rich diet participants saw comparable weight loss to the other study groups. However, they exhibited the most improvement in lipid levels, especially in those who are insulin-resistant.
In addition to a significant decrease in low-density lipoprotein (LDL) cholesterol, the walnut participants achieved a greater increase in High-density lipoprotein (HDL) cholesterol as compared to the other diet groups.
Whereas the lower carbohydrate and higher fat diet participants were encouraged to consume foods higher in monounsaturated fats, the walnut-rich diet provided more polyunsaturated fats.
Walnuts are the only nut in which the fat is primarily polyunsaturated fat (13 grammes per ounce), including a significant amount of alpha-linolenic acid (ALA), the plant-derived form of omega-3 fatty acids (2.5 grammes per ounce).
Recent research from Harvard also shows health benefits of consuming polyunsaturated fats. The study suggested that people who replace saturated fats with polyunsaturated fats may live longer and have a lower risk of heart disease.
The study was published in the Journal of the American Heart Association.
