Biomarker‐calibrated estimates of self‐reported energy intake and risk of weight gain in postmenopausal women (272.1)
Authors: Tinker L.F. , Neuhouser M.L. , Zheng C. , Prentice R.L. , Beasley J.M. , Caan B. , Di C. , Howard B.V. , Johnson K.C. , Van Horn L. , Beresford S.A.A. , Seguin R.A. , Song Y. , Ryckman K.K. , Eaton C.B. , Mossavar‐Rahmani Y. , Thomson C.A. , Hingle M. , Stern J.H. , Tindle H.A. , Qi L. , Waring M.E. 
Published: June 2021

Postmenopausal weight gain contributes to chronic disease risk. However, under‐reporting of energy intake, particularly among overweight or obese women, obscures the relationship of self‐reported energy intake with weight gain and challenges epidemiologic research. The purpose of the research was to investigate the association of self‐reported uncalibrated and biomarker‐calibrated dietary energy intake with 3 year body weight gain among postmenopausal women. Data were from the Women’s Health Initiative Observational Study (OS) (n=93,676), a US nationwide study of postmenopausal women’s health. Dietary self‐report was assessed by a food frequency questionnaire (FFQ) designed to capture usual intake over 3 months. Energy intake is reported as the geometric mean of average daily kcalories (kcal). Biomarker calibration equations, developed from a doubly labeled water substudy (n=450), were applied to baseline and year 3 FFQs in the full OS sample to estimate biomarker‐calibrated energy intakes. Body weight was measured at baseline and year 3 using standardized procedures and equipment. Weight gain was defined as year 3 weight being 蠅3% higher than baseline weight (Table 1).

Table 1. Womenâ€™s Health Initiative Observational Study

Age, years (n)
Dietary Self‐Reported IntakeFFQ, kcal, geometric mean (95% CI)
Body weight, kg (95% CI)
Percentage of participants who gained â‰¥3% body weight baseline to year 3

Baseline
Baseline
Baseline
Baseline to year 3

Uncalibrated
Biomarker‐Calibrated

50‐79
1467 (704, 2981)
2133 (1763, 2680)
71.2 (49.5, 109.8)
32% (n=17080/53,994)

50‐59
1501 (710, 3092)
2314 (2020, 2839)
72.7 (50.1, 115.0)
39% (n=6751/17,449)

60‐69
1468 (707, 2955)
2120 (1845, 2572)
71.7 (50.0, 109.6)
31% (n=7511/24,397)

70‐79
1420 (691, 2846)
1929 (1690, 2276)
68.3 (48.0, 100.0)
23% (n=2818/12,148)

Odds ratios (OR) were computed for 3‐year weight gain (蠅3%) associated with 1% increase in annual rate of change in energy intake (Table 2). Tests for OR=1 gave p蠄.05 using either uncalibrated or bio‐marker calibrated energy, although those using calibrated estimates revealed stronger and more plausible associations between energy intake and weight gain.

Table 2. Association of self‐reported uncalibrated and biomarker‐calibrated energy intakea with 3 year body weight gain of â‰¥3% among postmenopausal women

Age in years at baseline (n)
Uncalibrated Energy IntakeOR (95% CI)
Biomarker‐Calibrated Energy IntakeOR (95% CI)

50‐79 (53,994)
1.01 (1.01, 1.02)
1.27 (1.15, 1.73)

50‐59 (17,449)
1.02 (1.01, 1.02)
1.32 (1.18, 1.94)

60‐69 (24,397)
1.01 (1.01, 1.02)
1.27 (1.16, 1.77)

70‐79 (12,148)
1.01 (1.00, 1.01)
1.16 (1.06, 1.45)

a. 1% increase in annual rate of change in uncalibrated and biomarker‐calibrated energy intake.

In conclusion, biomarker calibrated estimates of energy intake are more likely to show an association of increasing energy intake with weight gain. Thus, biomarker‐calibrated energy intake estimates are the preferred exposure measure when investigating epidemiologic dietary associations with body weight.Grant Funding Source: Supported by R01 CA119171‐04A1, R01 CA119171