Reduction in appetite and/or food intake among older individuals is referred to as anorexia of aging (AOA, also known as Geriatric Anorexia). AOA is linked with myriad comorbidities associated with aging, contributes significantly to adverse health consequences in old age, and has been used as a predictor of morbidity and mortality. The overall aim of this study is to assess the feasibility and burden of the proposed in-laboratory and out-of-laboratory assessments to study Geriatric Anorexia. This will be accomplished with the use of questionnaires as well as devices that evaluate movement, metabolism, body weight composition, glucose levels, and nutritional scale.

This is a study to evaluate movement, metabolism, body weight composition, glucose levels, and nutritional scale in healthy adults. Subjects, age 65 to 85 years will be recruited.

The proposed study will consist of an initial (in-clinic) intake visit on Day 1 where the subject will be screened and enrolled in the study after signing an informed consent document, followed by an at-home phase where the subject will wear a watch like device on one wrist. After training, the subject will return for their Day 8 in-clinic visit, where the subject will repeat some intake assessments and activities, as well as some additional standing and walking activities. The subject will then be asked to perform at-home activities and assessments with the use of a smart phone, digital food scale, smart body weight scale, and continuous glucose monitor, while continuing to wear the watch-like device and a movement measurement device around their waist (Days 8-21). A final in-clinic visit will take place on Day 21 for final assessments and device collection. A +/- 4 days will be allocated for the scheduling of all visits to accommodate subject's schedules and commitments. All in-laboratory activities will take place in the Laboratory for Human Neurobiology while in-home activities will be completed in the subject's home. The study procedures will be identical for all subjects for the three groups.

Inclusion Criteria:

[separated into the three groups based on the Fried Criteria: 0, 1-2, 3 or above]

• Male or female participants aged 65 - 85 years.
• No clinically significant health problems other than well controlled chronic conditions (e.g., allergies and dermatitis)
• No recent hospitalizations/acute events in last 12 months.
• No active or recent (within 12 months) cancer diagnosis except skin cancer (limited to only non-complicated Squamous Cell Carcinoma (SCC)/Basal Cell Carcinoma (BCC)).
• Body mass index (BMI) < 30 kg/m2
• Able to understand and cooperate with study procedures and able to read, understand and provide informed consent. Evidence of a personally signed and dated informed consent document indicating that the participant has been informed of all pertinent aspects of the study
• Participants should not have any food aversion which could influence their food selection if standardized meals are used as part of the protocol.
• Native English speakers or demonstrated fluency in English as determined by the Investigator.
• Wide Range Achievement Test (WRAT-4) Word Reading Subtest equivalent to 8th grade reading level or greater.
• Normal or corrected-to-normal vision

Exclusion Criteria:

• Treatment with an investigational drug within 30 days of enrollment
• A moderate to severe alcohol use disorder diagnosis within 6 months of the screening as disclosed by the subject
• Subjects who are investigational site staff members directly involved in the conduct of the study and their family members, site staff members otherwise supervised by the investigator, or subjects who are Boston University/Boston Medical Center directly involved in the conduct of the study
• Inability to comply with study requirements.
• Has any clinically significant medical disorder, condition, disease or clinically significant finding at screening that precludes subject's participation in study activities including any self-reported diagnosis of eating disorders.
• Participants with electronic implant devices, such as pacemaker.
• Non-English Reader as measured by the WRAT-4.

Healthy adults