Pistachio nuts in a weight loss programme
What it found
Overweight and obese adults who were given pistachio nuts alongside a weight loss programme lost about the same amount of weight as those who were not.
Their blood pressure fell, and their diets shifted towards more fibre and fewer sweets.
What they found
Studies in people
Weight change
Weight fell by about 5.1% in the control group and 4.9% in the pistachio group, a similar amount in both. Body mass index and waist circumference also fell in both groups.
Blood pressure
Systolic and diastolic blood pressure fell significantly in the pistachio group but not in the control group. There was no significant difference between the groups at either time point.
Blood fats and sugar
Total cholesterol, triglycerides and LDL cholesterol fell in both groups but not significantly. HDL cholesterol, glucose and insulin changed little in either group.
Carotenoids in blood
Alpha-carotene, beta-carotene and lutein rose significantly in the pistachio group. Lutein also rose in the control group.
Diet changes
The pistachio group ate more fibre and less sweets than the control group, and cut back on added fats. Their diet quality score improved in both groups.
What the authors conclude
“Pistachios are a nutrient-dense tree nut that can contribute to a healthy dietary pattern and weight reduction, in the context of an energy-restricted diet in a behavioral intervention, and may confer additional health benefits such as a reduction in systolic and diastolic blood pressure.”
Also in their conclusions
- They say regular pistachio consumption was associated with a comparable degree of weight loss and similar reductions in BMI and waist circumference compared to controls.
- They conclude that pistachios can contribute to a healthy dietary pattern and weight reduction in the context of an energy-restricted diet in a behavioural intervention, and may confer additional health benefits such as a reduction in systolic and diastolic blood pressure.
- They note that regular pistachio consumption is associated with healthful shifts in dietary intake and food choices, including increased dietary fiber, decreased consumption of sweets, and a more favorable ratio of poly- and monounsaturated fatty acids to saturated fatty acids.
How it was done
Nuts are energy-dense but nutrient-dense, and studies have linked regular nut eating with lower body mass index and less weight gain in adulthood. Most nut trials have tested almonds and walnuts, so the authors wanted to test pistachios in overweight and obese adults during a weight loss programme.
They randomly assigned 100 non-diabetic overweight or obese men and women to a 4-month behavioural weight loss programme alone, or the same programme plus 1.5 oz (42 g) of pistachios a day. Weight, waist, blood pressure, blood fats, blood sugar, insulin and diet were measured at the start and after four months.
What it can’t tell you
- The study lasted only four months, so it cannot show what happens over a longer period.
- The participants had generally normal blood fats, glucose and insulin at the start, so the results may not apply to people with higher levels.
- Dietary intake was self-reported, so it may not be completely accurate.
Who paid
- Funding
- Funded by American Pistachio Growers (from the PubMed record).
- Conflicts
- The authors declare no conflicts of interest.
- Authors work at
- University of California, USA
The paper
- Title
- Effects of Pistachio Consumption in a Behavioral Weight Loss Intervention on Weight Change, Cardiometabolic Factors, and Dietary Intake
- Type
- Randomised controlled trial
- Evidence
- Studies in people
- Summarised from
- Full text
- Licence
- CC BY. Words in quotation marks are the authors’; the rest is our summary.
- Cite
- Rock CL, Zunshine E, Nguyen HT, et al (2020). Effects of Pistachio Consumption in a Behavioral Weight Loss Intervention on Weight Change, Cardiometabolic Factors, and Dietary Intake. Nutrients. doi:10.3390/nu12072155Free full textPubMed 32698457DOI
Summary written 30 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error