Energy Value of Macronutrients From Pistachio Nuts and Mechanisms of Nutrient Action

Inclusion Criteria:

* Age 25 to 65 years at beginning of study
* BMI between 20 and 38 kg/m2
* Fasting glucose \< 126 mg/dl
* Blood pressure \< 160/100 (controlled with certain medications)
* Fasting total blood cholesterol \< 280 mg/dl
* Fasting triglycerides \< 300 mg/dl

Exclusion Criteria:

* Presence of kidney disease, liver disease, gout, hyperthyroidism, untreated or unstable hypothyroidism, certain cancers, gastrointestinal disease, pancreatic disease, other metabolic diseases, or malabsorption syndromes
* Type 2 diabetes requiring the use of oral antidiabetic agents or insulin
* History of bariatric or certain other surgeries related to weight control
* Smokers or other tobacco users (during 6 months prior to the start of the study)
* Antibiotic use during the intervention or for 3 weeks prior to any intervention period
* History of eating disorders or other dietary patterns which are not consistent with the dietary intervention (e.g., vegetarians, very low fat diets, high protein diets)
* Volunteers who have lost 10% of body weight within the last 12 months or who plan to initiate a weight loss program during the next 10 months
* Known (self-reported) allergy or adverse reaction to pistachios or other nuts
* Unable or unwilling to give informed consent or communicate with study staff
* Self-report of alcohol or substance abuse within the past 12 months and/or current acute treatment or rehabilitation program for these problems (long-term participation in Alcoholics Anonymous is not an exclusion)
* Other medical, psychiatric, or behavioral factors that in the judgment of the Principal Investigator may interfere with study participation or the ability to follow the intervention protocol