Supplementing a reduced-energy diet with walnuts can provide results similar to conditions under a weight loss intervention. The results of this study, led by researchers from the University of California, La Jolla, looked at how adding walnuts to a diet can affect weight, risk factors for cardiovascular disease (CVD), and satiety.
For the study, the research team randomly selected 100 non-diabetic overweight and obese men and women from a screened sample of 647 individuals. Participants were aged 21 years and older, had a body mass index (BMI) between 27 and 40 kilograms per square meter, and did not have an allergy to tree nuts.
Each participant was randomly assigned to either a standard reduced-energy-density diet or a walnut-enriched (15 percent of energy) reduced-energy diet.
The team then assessed the participants during follow-up clinic visits on the third and sixth month. Participants were asked to rate their hunger, fullness, and possibility of continuing the diet.
Data such as body measurements, blood pressure, physical activity, lipids, tocopherols, and fatty acids were also collected and studied using repeated measures mixed models.
The findings revealed that while both groups lost body weight, BMI, and waist circumference, the standard group had a -9.4 percent (with a mean standard error of 0.9) reduction in weight while the walnut-enriched group posted -8.9 (at 0.7 mean SE). In terms of systolic blood pressure, both groups were able to lower it in the third month, but only the walnut-enriched group was able to sustain it for the sixth month. The group also minimized total cholesterol (from 203 to 194 milligrams per deciliter) and low-density lipoprotein (LDL) cholesterol levels (from 121 to 112 milligrams per deciliter) at six months.
While losing weight in an intervention setting may increase the risk factors for CVD, researchers posited that the diet proved useful in managing LDL cholesterol and systolic blood pressure.