The goal of this clinical trial is to learn about the effects of avocado consumption on gastrointestinal health in adults with overweight and obesity. The main questions is aims to answer are:

How does avocado consumption affect the gut microbiome? How does avocado consumption affect thinking? Are there connections between the microbiome and cognition? Participants will be asked to eat provided meals with and without avocados for three 4-week periods. At the end of each 4-week period, participants will be asked to provide stool samples and complete computer games that assess thinking and memory.

Inclusion Criteria:

• Participants must be between the ages of 25 and 74 years old
• BMI ≥ 25 kg/m2
• Ability to drop off fecal sample within 15 minutes of defecation
• 20/20 or corrected vision

Exclusion Criteria:

• Avocado allergy or intolerance
• Food allergies or intolerances
• Prior diagnosis of liver or gastrointestinal disease (primary biliary cirrhosis or gallbladder disease, chronic constipation, diarrhea, Crohn's disease, celiac disease, ulcerative colitis, irritable bowel syndrome, diverticulosis, stomach or duodenal ulcers), diabetes, hepatitis, HIV, or cancer
• Women that are pregnant, have given birth in the previous 12 months or are lactating
• Individuals that smoke, use tobacco, abuse drugs, or consume > 2 alcoholic beverages per day.
• > 5% weight change in the past month or > 10% change in the past six months
• Oral antibiotics during the previous 6 weeks.
• Currently taking lipid-lowering medications, oral hypoglycemic agents, or insulin.
• History of malabsorptive or restrictive bariatric surgeries (e.g., gastric bypass, sleeve gastrectomy, adjustable gastric band) or gall bladder removal surgery.
• Are unable to consume the experimental meals/snacks.
• Allergic to latex
• Concurrent enrollment in another dietary, exercise, or medication study