Identifying the Best Tools for Recording Diet in Free-living UK Adults (SODIAT-2 Study)

Inclusion Criteria: * 18 years and older * Lives in Great Britain (England, Schotland and Walse) * Able to read/understand instructions written in English and are fluent in English Exclusion Criteria: * Diagnosed or self-report as being underweight (have a body mass index (BMI) of less than 18.5 kg/m2) * Are unwilling/unable to collect urine and blood samples, use the wearable camera as instructed and/or spend 20-30 min online recording what they've recently had to eat/drink on multiple occasions * Are unwilling/unable to have a video call with a researcher with cameras turned on * Are unwilling/unable to post samples on specific days and receive/send a larger parcel at the start/end of the study (note: all return packaging and postage will be provided by us and will include a courier delivery and collection) * Are unwilling/unable to receive a single grocery delivery from Sainsbury's or Tesco online supermarkets (delivery to be arranged by us), includes living in a postcode area that cannot receive grocery deliveries from Tesco or Sainsburys as well as not having space to refrigerate and freeze items. * Are unwilling/unable to eat/drink any items on the calibration menu, e.g., food allergies/intolerances, dislike of food items, unable eat (e.g. vegan or have to avoid for a medical condition) or cannot eat 3 meals plus snacks daily (note: vegetarians can take part) * Are unwilling/unable to avoid taking dietary and herbal supplements for at least 1 week before and during the 5-week study (e.g. fish oils, vitamins, iron, protein shakes, nutrient powders, joint care) * Are pregnant, may be pregnant or breast-feeding * Currently experiencing, recovering or at a high risk of an eating disorder (e.g., previous diagnosis, or concerns that you have an unhealthy relationship with food) * Have a health condition, are taking medication and/or undergoing medical treatment that affects metabolism, appetite and/or ability to eat the calibration menu (e.g. cancer, chemotherapy, diabetes, gastrointestinal disorders (such as inflammatory bowel disease, Crohn's disease), kidney disease, liver disease, HIV or AIDS) * Are taking any of the following medications: androgens, blood thinners, phenytoin, erythromycin, or thyroid hormones * Long-term use of any of the following medications: anti-inflammatories (NSAIDS), steroids/corticosteroids or antibiotics (eligible following a 4-week washout after short term use; eligible if use is infrequent) * Use illicit substances/recreational drugs * Have been diagnosed with dementia or other conditions affecting memory * Do not have anyone at home, work, etc. to help them if they require assistance to use the study tools (such as arthritis, Parkinson's disease, sight loss, etc.) If the participants have recently taken part in another intervention study, a 4-week washout will be required before they are able to start the study.