Assessing Diet, Stress Scores, and Other Health Metrics in Healthy Northern California Adults

Characterization, Perceived Stress Scores, Nut Consumption and Bowel Patterns of a Healthy Adult Population in Northern California: A Pilot Study

The purpose of this study is to gather health and nutrition data from the population of Davis, CA and surrounding areas. This data will be used to help us test and improve our study procedures for a larger planned study on peanut consumption and effects on cardiovascular disease (CVD) risk.

Study Overview

• Status: Completed
• Conditions: Food Allergies; Diet Surveys; Chronic Stress; Demographic Data; Stool Frequency
• Intervention / Treatment: Other: Online Survey

Detailed Description

Participants will be recruited to complete an online survey asking questions about their stress levels, nut consumption, bowel patterns, body measurements, and county of residence. This data will be used to gain insight into the characteristics of this population.

• Study Type: Observational
• Enrollment (Actual): 300

Contacts and Locations

Study Locations

• United States
  • California
    • Davis, California, United States, 95616
      • USDA Western Human Nutrition Research Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

• Sampling Method: Non-Probability Sample

Study Population

Adults 18-65 years old, currently living in Yolo, Sacramento, Solano, Sutter, or Placer counties

Description

Inclusion Criteria:

• Adults 18-65 years old
• Currently living in Yolo, Sacramento, Solano, Sutter, or Placer counties
• Able to complete an online survey written in English, on mobile phone, tablet, or computer

Exclusion Criteria:

• Previous participation in the study

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Adults living in and around Davis, CA; Adults 18-65 years old, currently living in Yolo, Sacramento, Solano, Sutter, or Placer counties	Other: Online Survey; Online survey containing a Perceived Stress Score - 4 instrument, a modified food frequency questionnaire, and will measure reported age, sex, geographical location, usage of prescription medications, food allergies, and stool frequency and consistency.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Perceived Stress Score	Measured using a validated tool for assessing perceived psychosocial stress within the last month, the Perceived Stress Scale 4 (PSS-4). Participants will report their answers to 4 questions in frequencies ranging from "Never" to "Very Often" on a 5 point scale	Baseline
Nut Consumption Frequency and Quantity	Participants will input frequencies of nut and nut butter consumption and amounts of nuts and nut butter consumed in a typical month, using a modified food frequency questionnaire. Frequency will be reported as values ranging from "Never" to "6 or more times a week". Nut and nut butter consumption will be reported in cups and tablespoons	Baseline

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Consumption Frequency of Nut-Containing Foods	Reported as monthly consumption of nut containing foods (granola, cereal, pastries, breads, or other snacks or sweets) in frequencies ranging from "Never" to "6 or more times per week"	Baseline
Prevalence of Food Allergies	Reported as allergies to any of 9 common food allergens: (Peanuts, Tree Nuts, Egg, Wheat, Soy, Shellfish, Fish, Sesame, and Milk)	Baseline
Stool Frequency	Reported as usual number of bowel movements per week	Baseline
Stool Consistency	Reported using images of Bristol Scale stool types	Baseline
Body Mass Index (BMI)	Calculated using participant-reported height and weight	Baseline
Prescription Drug Use	Participants will confirm or deny intake of medications from 6 categories: (Asthma medications, Antibiotics or antivirals, weight loss medications, cholesterol or lipid lowering medications, blood pressure medications, or psychiatric medications)	Baseline
Age	Reported as age in years	Baseline
Biological Sex	Reported as sex assigned at birth	Baseline
Geographic Data	Reported as current county of residence	Baseline

Collaborators and Investigators

• Sponsor: USDA, Western Human Nutrition Research Center
• Investigators: Principal Investigator: Ryan Snodgrass, PhD, United States Department of Agriculture - Western Human Nutrition Research Center

Study record dates

Study Major Dates

• Study Start (Actual): December 8, 2025
• Primary Completion (Actual): January 20, 2026
• Study Completion (Actual): January 20, 2026

Study Registration Dates

• First Submitted: November 20, 2025
• First Submitted That Met QC Criteria: December 1, 2025
• First Posted (Actual): December 5, 2025

Study Record Updates

• Last Update Posted (Actual): January 29, 2026
• Last Update Submitted That Met QC Criteria: January 27, 2026
• Last Verified: January 1, 2026

More Information

Terms related to this study

• Keywords: Stress; Diet; Survey; Observational Study; allergens; Online Survey
• Additional Relevant MeSH Terms: Immune System Diseases; Hypersensitivity, Immediate; Hypersensitivity; Food Hypersensitivity
• Other Study ID Numbers: 2337131

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No