Table 1.

Operationalization of WCRF/AICR dietary and lifestyle scores in the Nurses' Health Study and Health Professionals Follow-up Study

Points
Recommendation00.51
1. Consume 5+ servings of fruits and vegetables per daya<2.5 servings/day2.5–<5 servings/day≥5 servings/day
2. Consume 30+ grams/day fibera<15 g/day15–<30 g/day≥30 g/day
3. Include in most meals foods containing whole grains, nonstarchy vegetables, fruit, and pulses such as beans and lentils
 Consume 3+ servings of whole grains or pulses per dayb<1.5 servings/day1.5–<3 servings/day≥3 servings/day
4. Limit consumption of ‘fast foods’ and other processed foods high in fat, starches, or sugars
 Avoid intake of refined grains, pastries, sweets, and salty snacksc≥3 servings/day1.5–<3 servings/day<1.5 servings/day
5. Limit intake of red and processed meats
 Consume no more than 3 servings/week of red meatd≥6 servings/week>3–<6 servings/week≤3 servings/week
 Consume little to no processed meate≥27 g/day3–<27 g/day<3 g/day
6. Limit intake of sugar-sweetened beveragesf
 Limit intake of sodas and other beverages with added sugars≥1 drinks/day0–<1 drinks/day0 drinks/day
 Limit intake of juices≥2 drinks/day1–<2 drinks/day<1 drink/day
7. Limit intake of alcoholic beveragesg
 Men≥2 drinks/day>0–<2 drinks/day0 drinks/day
 Women≥1 drinks/day>0–<1 drink/day0 drinks/day
8. Maintain a healthy body weight
 Maintain a healthy BMIh<15 or ≥3015–<18.5 or 25–<3018.5–<25
 Avoid weight gaini≥10 lb. gained in last 10 years0–<10 lb. gained in last 10 yearsNo weight gain in last 10 years
 Maintain a healthy waist circumference (men)j,k≥40.2 inches37–<40.2 inches<37 inches
 Maintain a healthy waist circumference (women)j≥34.6 inches31.5–<34.6 inches<31.5 inches
9. Be physically active and limit sedentary behaviors
 Engage in moderate physical activity (PA)l<75 min moderate PA/week75–<150 min moderate PA/week≥150 min moderate PA/week
 Limit sedentary behaviorsm≥20 hours/week TV watching5–<20 hours/week TV watching<5 hours/week TV watching
  • aThe cutoffs for adherence (i.e., 1 point) for the recommendations on fruits and vegetables and fiber were provided by the Third Expert Report. We considered participants partially adherent if they consumed less than the Third Expert Report's recommended intake but at least half of the recommended amount, and nonadherent if they consumed less than half of the recommended amount.

  • bThe cutoff for adherence for the recommendation on whole grains and pulses was not provided by the Third Expert Report. Because the Third Expert Report recommends these foods to be included in “most meals,” we considered participants to be adherent if they consumed at least 3 servings per day on average (roughly once per meal), partially adherent if they consumed less than 3 servings per day but more than 1.5 servings per day on average (i.e., less than the recommended intake but at least half of the recommended amount), and nonadherent if they consumed less than 1.5 servings per day (i.e., less than half the amount used to define adherence). We did not include fruits or vegetables in this component because these food groups were considered in component 1.

  • cThe Third Expert Report does not provide cutoffs for the recommendation on “fast foods and other processed foods high in fat, starches, or sugars,” and instead broadly recommends little intake of these foods. Thus, we considered participants to be adherent if they consumed less than 1.5 servings of these foods per day or less (roughly half a serving per meal or less), partially adherent if they consumed more than 1.5 servings but less than 3 servings per day (i.e., roughly between half and a whole serving per meal), and nonadherent if they consumed 3 servings per day or more. We included in this category foods that are frequently industrially processed and/or contain a large amount of refined grains, saturated fat, and sodium. We did not include foods that overlapped with other WCRF/AICR recommendations, such as processed meats and sugar-sweetened beverages.

  • dThe cutoff for adherence for the recommendation on red meat was provided by the Third Expert Report. We considered participants partially adherent if they consumed more than the recommended intake but less than double the recommended amount, and nonadherent if they consumed double the recommended intake or more.

  • eThe Third Expert Report does not provide cutoffs for the recommendation on processed meats and instead recommends “very little, if any” consumption. We therefore considered participants to be adherent if they consumed less than 3 g/day (equivalent to approximately 1 serving per week), partially adherent if they consumed more than 3 but less than 27 g/day (roughly between 1 and 7 servings per week), and nonadherent if they consumed 7 servings per week or more (i.e., 1 serving per day or more).

  • fThe cutoff for adherence for the recommendation on sugar-sweetened beverages was provided by the Third Expert Report (i.e., “do not consume sugar-sweetened drinks”). We therefore considered participants adherent if they did not consume beverages with added sugar, partially adherent if they consumed less than 1 beverage with added sugar per day, and nonadherent if they consumed more than 1 serving per day. We used different cutoffs for juices because they contain potential chemopreventive agents and are less strongly associated with weight gain and chronic disease risk than beverages with added sugars (61, 62).

  • gThe cutoff for adherence for the recommendation on alcohol was provided by the Third Expert Report (i.e., “for cancer prevention, it's best not to drink alcohol”), which also recommends that individuals do not exceed national guidelines if they do drink alcohol. We therefore considered participants adherent if they did not drink alcohol, partially adherent if they did not exceed the 2015–2020 Dietary Guidelines for Americans recommendation on alcohol (up to 2 drinks per day for men and up to 1 drink per day for women; ref. 63), and nonadherent if they exceeded these guidelines.

  • hThe Third Expert Report does not provide cutoffs for BMI, but says “it is best to maintain weight within the healthy range throughout adult life.” We therefore considered participants to be adherent if their BMI was in the normal range, partially adherent if it was in the overweight or slightly underweight range, and nonadherent if it was in the obese range or severely underweight range.

  • iThe Third Expert Report does not provide cutoffs for the recommendation on weight gain and instead broadly recommends to “avoid weight gain throughout adulthood.” Because long-term weight gain is most strongly associated with cancer risk (12, 13), we considered participants adherent if they did not gain weight in the past 10 years, partially adherent if they gained less than 10 pounds in the past 10 years, and nonadherent if they gained more than 10 pounds over the past 10 years. We chose these cutoffs based on the distribution of weight gain in the study population over the study period.

  • jThe cutoff for adherence for the recommendation on waist circumference was provided by the Third Expert Report, which adopts the guidelines of the World Health Organization (WHO). The cutoff for partial adherence was additionally provided by WHO guidelines (64).

  • kWaist circumference was not measured until 1987 in HPFS, so this component was excluded from the body weight component score calculation in 1986.

  • lThe cutoff for adherence for the recommendation on physical activity was provided by the Third Expert Report, which adopts guidelines of the WHO. We considered participants partially adherent if their physical activity was half or more than the recommendation but less than the recommendation, and nonadherent if they were less than half as physically active as recommended. We assumed that 1 minute of vigorous physical activity is equal to 2 minutes of moderate physical activity, and categorized activities as vigorous or moderate as defined previously (65).

  • mThe Third Expert Report does not provide cutoffs for the recommendation on sedentary activity and instead broadly recommends to “limit sedentary habits.” We used TV watching as a proxy for sedentary habits, which has been associated with chronic disease risk previously (57–59) and considered participants adherent if they watched TV less than 5 hours per week (roughly less than 45 minutes per day), partially adherent if they watched TV more than 5 but fewer than 20 hours per week (roughly between 45 minutes and 3 hours per day), and nonadherent if they watched TV more than 20 hours per week (roughly more than 3 hours per day). These categories were also chosen because of how the questionnaires assessed TV watching. TV watching was not measured until 1992 in NHS and HPFS, so this subcomponent was excluded from the physical activity component score calculation in 1986 and 1990.