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Calorie Restriction and Brain Function in Mild Cognitive Impairment


Problems with blood sugar metabolism, known as metabolic dysfunction, increase risk for Alzheimer's disease and affect memory and related brain function. This study will test intermittent calorie restriction as a way to reduce metabolic dysfunction in older adults with mild cognitive impairment (MCI), a precursor to Alzheimer's disease, who are overweight or obese.

Minimum Age Maximum Age Gender Healthy Volunteers
70 Years 85 Years All No
May 8, 2019
December 31, 2021

  • Body mass index of 28 to 39 and weight less than 350 pounds
  • Mini-Mental State Examination score of 24 or greater
  • Subjective memory concern from the participant, caregiver/informant, or a clinician
  • Education-adjusted score for the Logical Memory II, paragraph A Wechsler Memory Scale (16 years: 8-10; 8 to 15 years: 5-7; 0 to 7 years: 2-3)
  • Clinical Dementia Rating sum of boxes score of 0.5
  • No deficits in activities of daily living
  • Consensus confirmation of MCI by senior investigators
  • Informant/caregiver that can attend study visits

  • History of a major cardiovascular event (e.g., heart attack)
  • History of cerebrovascular or other neurological disorders (e.g., stroke, epilepsy, multiple sclerosis)
  • History of substance abuse in the past 6 months
  • History of eating disorders
  • History of clinically significant endocrine disorders (e.g., hypothyroidism)
  • History of mood and anxiety disorders (e.g., major depressive disorder, generalized anxiety disorder, bipolar disorder)
  • Prohibited medications: insulin, corticosteroids, warfarin, and Alzheimer's disease drugs (memantine, galantamine, donepezil, rivastigmine)
  • Having smoked tobacco products in the last 3 months
  • Contraindications for MRI (e.g., pacemakers, ferrous metal implants or shrapnel around the face or eyes)
  • Other medical history that could introduce risk for participation
  • High blood pressure, defined by a diastolic/systolic blood pressure greater than 160/110 mm Hg

Participants will be randomly assigned to the intervention or comparative group. The intervention group will consume one 530-calorie protein shake, with enough nutrients to sustain the person, per day for 2 consecutive days each week. Participants will eat as they want during the remaining 5 days. Participants in both groups will meet with a registered dietitian nutritionist about dietary modifications to induce moderate weight loss. Researchers will examine the effects of the intervention on weight loss, behavior, and brain outcomes.

Name City State Zip Status Primary Contact
Nutrition and Wellness Research Center
Ames Iowa 50011 Recruiting Auriel Willette, Ph.D.
University of Iowa Hospitals and Clinics
Iowa City Iowa 52242 Recruiting Steve Anderson

Iowa State University

  • National Institute on Aging (NIA)

Name Role Affiliation
Auriel A. Willette Principal Investigator Iowa State University

Name Phone Email
Auriel A. Willette 515-294-3110
Steve Anderson 319-356-3428


Intermittent Calorie Restriction and Brain Function in MCI