The objective of this randomized, controlled feeding study is to investigate the potential health benefits of a pecan-containing diet. The investigators hypothesize the chronic consumption of pecans will improve an array of biomarkers related to cardiovascular disease and type 2 diabetes risk, including indices of oxidative stress, antioxidant activity, inflammation, endothelial function, and insulin resistance when compared with a control diet that is absent nuts.

Inclusion Criteria:

• Men & postmenopausal women, age 50 years and over
• BMI 25-35 kg/m2
• Waist/hip >0.8 for women and >0.9 for men
• Blood pressure between 120/80 and 159/99

Exclusion Criteria:

• Cigarette smoking and/or nicotine replacement use
• Individuals taking estrogen
• Use of cholesterol-lowering medications
• Use of blood pressure-lowering medications
• Regular use of any stomach acid-lowering medications, laxatives (including fiber supplements) or anti-diarrheal medications (prescription or over-the-counter [OTC])
• Cardiovascular (heart) disease
• Gastrointestinal disease
• Kidney disease
• Endocrine disease: including diabetes, unstable thyroid disease
• Autoimmune disease: including rheumatoid arthritis, gout, lupus, HIV
• Active treatment for any type of cancer, except basal cell carcinoma, within 1 year prior to study admission
• Systolic blood pressure > 159 mmHg and/or diastolic blood pressure > 99 mmHg
• Regular use of oral or injectable steroids
• Gain or loss of > 10% of body weight within previous 3 months; unwillingness to maintain your weight
• Regular daily intake of ≥ 2 alcoholic drinks
• Vegetarians
• Current allergy to any kind of nut
• Dietary supplement use, including those containing any vitamins, minerals, herbs, plant concentrates (including garlic, gingko, St. John's wort) homeopathic remedies, probiotics, or fish oil (including cod liver oil), for one month prior to study admission