A dual-site dietary intervention study to integrate dietary assessment methods

INTERVENTION: The study visits will take place at the NIHR/Imperial Clinical Research Facility at Hammersmith Hospital or the Hugh Sinclair Unit of Human Nutrition at the University of Reading and will include two 4‐day study periods as follows: Study period 1 will involve 4 full day visits and another visit on the 5th day to return samples and study equipment. Between the two‐study period, there will be a minimum of a 1‐week gap. Study period 2 will involve the same number of visits as study period 1. For the respective study period, participants will be asked to attend the research unit at 8 am every morning of the eight study days, following a 12‐hour overnight fast (not consuming any food or drink, except water) and remain in the unit until 6 pm. Blood pressure, height and body weight will be measured when they arrive on the first day of each study period. Simple randomisation will be used to assign the order in which participants receive the intervention menus. In randomised order, participants will receive a test diet during each study period that has a different level of compliance with UK healthy eating guidelines. Diet 1 is designed to be far from meeting healthy eating dietary guidelines (e.g., high in saturated fat, free sugars, and salt and low in fruit, vegetables, and fibre), whereas Diet 2 is compliant with healthy eating dietary guidelines (e.g., high in fibre, fruits and vegetables, and low in saturated fat, free sugars and salt). Participants will be served meals and snacks throughout the eight study days (8 am – 6 pm) according to the diet they have been randomly assigned during each study period. Diets will consist of a 2‐day repeating menu (e.g., menu 1 on days 1 and 3, and menu 2 on days 2 and 4). At 6 pm of the four study days, they will return home with CONDITION: Nutritional intake ; Nutritional, Metabolic, Endocrine PRIMARY OUTCOME: The accuracy of dietary reporting will be measured at the end of each intervention week using dietary data collected from wearable micro cameras, spot urine samples, capillary blood samples, and self‐report dietary recalls. Total daily consumption (grams per day) will be reported by wearable micro cameras and self‐report dietary recalls. Liquid chromatography‐mass spectrometry (LC‐MS) will measure biomarkers of dietary components in spot urine samples and capillary blood samples and daily dietary intake will be reported using µg/ml concentrations of dietary exposure biomarkers. SECONDARY OUTCOME: 1. Creation of a multiplatform model of dietary intake using g/day measured from wearable micro‐cameras and self‐report dietary recalls, and µg/ml of dietary exposure biomarkers from spot urine samples and capillary blood samples at the end of the study; 2. Design a dietary intake study informed by the results of the dietary intake study protocol in a free‐living population at the end of the study; ; INCLUSION CRITERIA: 1. Aged 18 – 70 years 2. Body Mass Inde X(BMI) 20‐30 kg/m²