Metabolic Health, Bones and Nuts During Weight Loss in Adults

The aging population is rapidly increasing, and it is important to identify dietary factors that can prevent disease and promote health in this group. Legumes, such as peanuts, are a plant-based food high in protein and unsaturated fat making this a healthy choice but are not consumed frequently enough in older adults. Studies have shown that regular nut consumption is associated with lower adiposity and reduced weight gain, and several dietary pattern studies indicate that nuts and legumes are associated with better bone health. In addition, our preliminary translational data indicates that a higher monounsaturated fatty acid (MUFA) intake is associated with improved bone mineral density (BMD) and quality. Given these findings, the proposed study aims to examine the impact of consuming peanut products on bone health, metabolic health (e.g., serum glucose, insulin, lipids and inflammation), markers of brain and sleep health, and physical function in overweight and obese older adults before and after a six-month weight loss intervention using a randomized controlled design. The results of this study have the potential to provide valuable insights into the role of peanuts as a sources of fatty acids in promoting health and preventing disease in at-risk adults.

The aging population is rapidly increasing, and it is important to identify dietary factors that can prevent disease and promote health in this group. Legumes, such as peanuts, are a plant-based food high in protein and unsaturated fat making this a healthy choice but are not consumed frequently enough in older adults. Studies have shown that regular nut consumption is associated with lower adiposity and reduced weight gain, and several dietary pattern studies indicate that nuts and legumes are associated with better bone health. In addition, our preliminary translational data indicates that a higher monounsaturated fatty acid (MUFA) intake is associated with improved bone mineral density (BMD) and quality. Given these findings, the proposed study aims to examine the impact of consuming peanut products on bone health, metabolic health (e.g., serum glucose, insulin, lipids and inflammation), markers of brain and sleep health, and physical function in overweight and obese older adults before and after a six-month weight loss intervention using a randomized controlled design. The results of this study have the potential to provide valuable insights into the role of peanuts as a sources of fatty acids in promoting health and preventing disease in at-risk adults.

Specific Aims

1. To determine whether consuming peanuts daily compared to a control group (no nuts) during lifestyle intervention has a differential effect on bone mineral density in older adults who are overweight or obese.
2. To determine the temporal change in bone turnover biomarkers and bone regulating hormones during weight loss in the diet in older adults with overweight or obesity. Exploratory outcomes will examine metabolic biomarkers (serum glucose, insulin, lipid levels), and other markers of brain and sleep health and physical function.

Eligibility Criteria:
Inclusion Criteria:

* Men and postmenopausal women (\>2 years since last menses), ages 50-75 years
* Body mass index (25-42 kg/m2) or evidence of pre-clinical obesity.
* Agree to be randomly assigned to consume a daily peanut snack or nut-free snack for 24 weeks
* Must attend on-site visits (about 10) in New Brunswick, NJ, USA (transportation/reimbursement for travel not included)

Exclusion Criteria:

* Peanut allergies or intolerances
* Participants with \>5% weight loss in the past 6 months or extreme dietary/physical activity habits
* An inability to follow the experimental intervention or to perform the required specimen collections.
* Individuals with significant psychiatric or food disorders.
* Current diagnosis, or history of cancer in past 3 years.
* Current diagnosis or history of bone diseases, type I or II diabetes, gastrointestinal disease, hyperparathyroidism, untreated thyroid disease, significant immune, hepatic, cardiac, or renal disease.
* Uncontrolled hypertension or hyperlipidemia in abnormal ranges.
* History of surgery in the past 6 months or surgical procedure for weight loss in the past 3 years.
* Regular use of medications that affect bone metabolism, including bisphosphonates or hormone replacement.
* Regular use of medications for that affect the gastrointestinal tract including incretin mimetics, cholecystitis, urinary tract infection, severe organic diseases including coronary heart disease, myocardial infarction, infectious diseases including pulmonary tuberculosis and AIDS.
* Antibiotic use in the past month
* Alcohol or illicit drug abuse
* Any other condition deemed by the Research Physician that would prevent participation in the study, e.g. participation in another clinical research project that may interfere with the results of this study.
* Participation in another clinical interventional research trial