The study aims to evaluate the metabolizable energy of the typical American diet with and without the inclusion of fiber. We hypothesize that including fiber in the diet will decrease the metabolizable energy of the diet resulting in more nutrient loss into the feces and urine.

The study will be a randomized, crossover, controlled feeding trial comprised of 2 experimental periods: 1) control and 2) fiber. Each experimental condition will be 16 days in length. There will be at least a 12-day compliance break between each period. Participants will undergo complete urine and fecal collection for a period five to seven days during the second half of each experimental condition.

Inclusion Criteria:

• Adults ages 22-75 years
• BMI between 18.5 and 39.9 kg/m2
• Ability to drop-off 1 fecal sample within 15 minutes of defecation
• Ability to pick-up meals daily
• Ability to collect fecal and urine samples daily
• Fasting glucose of <126 mg/dL

Exclusion Criteria:

• Wheat allergy or intolerance
• Any food allergies or intolerances
• Prior diagnosis of metabolic or gastrointestinal disease (kidney disease, liver disease, gout, hyperthyroidism, untreated or unstable hypothyroidism, certain cancers, gastrointestinal disease, pancreatic disease, diabetes requiring medication)
• Women that are pregnant, had a baby within the last 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 year
• Oral antibiotics during the previous 6 weeks
• History of malabsorptive or restrictive bariatric surgeries (e.g., gastric bypass, sleeve gastrectomy, adjustable gastric band) or gall bladder removal surgery
• Are unable or unwilling to consume the experimental meals/snacks.
• Taking certain medications (Orlistat, bile binding resins, insulin, oral hypoglycemic agents, laxatives)
• Concurrent enrollment in another dietary, exercise, or medication study