Pastes

The 24 h dietary recalls were unannounced and obtained by telephone. A two-dimensional food portion visual (2D Food Portion Visual; Nutrition Consulting Enterprises, Framingham, MA, USA) was sent to each participant before the first recall to assist with portion size estimates. Trained research dietitians used standard probes and a multiple-pass approach methodology to collect detailed information on all foods, beverages and supplements consumed by each subject during the previous 24 h. Each recall interview was entered using Nutrition Data System for Research (NDS-R) version 4·06 or 5·0 (The Nutrition Coordinating Center, Minneapolis, MN, USA) and the conversation digitally recorded for subsequent quality check. An experienced research dietitian later evaluated randomly selected recall interviews ( ~5 %) and compared them with the recording, as a quality control measure.
The AHS-2 FFQ is a quantitative and comprehensive 22-page instrument consisting of 204 foods, fifty-four questions about food preparation and forty-six fields for open-ended questions. Frequency categories vary with food type to allow respondents to define their daily intake with greater specificity. Thus, the lowest category for most foods and beverages is never or rarely, and for cold cereals and vegetarian protein products, 1–3 per month. The highest frequency category for vegetables, soups, cereals, pasta, dressing, meats, fish, vegetarian protein products and soya milk is 2 or more per day; for nuts and seeds, 4 or more per day; for breads, eggs, dairy products, snacks and beverages, 6 or more per day. Portion sizes include three levels: standard, $\frac{1}{2}$ or less, and $1\frac{1}{2}$ or more. Standard portions are based on serving sizes using familiar household units such as cup, tablespoon, slice, patty and others. Pictures of common foods or beverages typically served together were included with the questionnaire to assist subjects in estimating portion sizes. For example, to represent a standard portion, spaghetti, broccoli and steak are arranged on an 11-inch dinner plate, each food measured in a standard portion. Representations of $\frac{1}{2}$ of standard and $1\frac{1}{2}$ times the standard portion size are provided as well, using the same foods and dinner plate.
The AHS-2 FFQ was designed to include foods commonly eaten by US Adventists and later modified to accommodate foods specific to black Adventists of US and Caribbean origin^{(6 (link))}. The questionnaire was sent to each subject, completed at home, and then mailed back to AHS-2. Respondents were asked to report on their intake over the previous one year. Upon receipt of the questionnaire, study personnel reviewed the questionnaire for completeness and as necessary followed-up by telephone to clarify any ambiguous or incomplete information.
Completed questionnaires were optically scanned using the NCS 5000i Image Scanner with ScanTools Plus software (Pearson NCS, Bloomington, MN, USA). Standardized processing of open-ended questions was done using the Food Write-In Processing software (Adventist Health Study-2, Loma Linda, CA, USA), a network-based application created in Microsoft® Access (Microsoft Corporation, Redmond, WA, USA).
Nutrient composition of foods reported from 24 h recalls and FFQ were based on the NDS-R 5·0_35 database (The Nutrition Coordinating Center), an analytic database of over 20 000 foods updated annually while maintaining nutrient profiles true to the version used for data collection^{(7 (link))}. Nutrient profiles of foods and supplements not found in the NDS database were obtained from the US Department of Agriculture, manufacturers, and the Caribbean Food and Nutrition Institute. Considerable attention was given to creating recipes for home-cooked vegetarian dishes (n > 500), home-made and commercial soya and nut milks (n > 180) and commercial meat analogues (n 309) frequently consumed among our study population. For the latter we contacted manufacturers or worked with a senior food technologist with experience in this industry, to create recipes.