Relationship between Non-Energy-Adjusted and Energy-Adjusted Dietary Inflammatory Index and the Healthy Eating Index-2015: an analysis of the National Health and Nutrition Examination Survey (NHANES) 2015–2018

Figures & data

Table 1. Food groups and nutrients used to assess the HEI-2015, DII and E-DII [7,9].

HEI-2015 components	DII and E-DII
Total fruits^a	Total energy^c
Whole fruits^a	Carbohydrates
Total vegetables^a	Fat
	Total
	Saturated
	Monounsaturated
	Polyunsaturated
Greens and beans^a	Fatty acids
	Omega3
	Omega6
Whole grains^a	Protein
Dairy^a	Alcohol
Total protein foods^a	Vitamins A, B1, B2, B6, B12, C, D, E
Dairy^a	Niacin
Total protein foods^a	Fiber
Seafood and plant proteins^a	Cholesterol
Fatty acids^a	Iron
Refined grains^b	Magnesium
Sodium^b	Zinc
Added sugars^b	Selenium
Saturated fats^b	Folic acid
	Beta carotene
	Caffeine

^aThese foods are considered “Adequacy” components used to score the HEI-2015.

^bThese foods are considered “Moderation” components used to score the HEI-2015.

^cThis is included only in DII score calculation, not E-DII score calculation.

HEI-2015: Healthy Eating Index-2015; DII: Dietary Inflammatory Index; E-DII: Energy-Adjusted Dietary Inflammatory Index.

Table 2. Bivariate analyses by DII quartile among participants from the National Health and Nutrition Examination Survey 2015–2018.

DII quartiles
N = 5289 total sample	Q1: n = 1935 (33.2%)	Q2: n = 1551 (26.6%)	Q3: n = 1259 (21.6%)	Q4: n = 1084 (18.6%)	p Value
DII quartile range	−4.77 to −1.31	−1.32 to 0.02	0.03–1.38	1.39–4.52	–
Categorical measures (n (% per total sample))
Gender					<0.001*
Males	1176 (20.17%)	760 (13.04%)	519 (8.90%)	388 (6.66%)
Females	759 (13.02%)	791 (13.57%)	740 (12.70%)	696 (11.94%)
Race/Ethnicity					<0.001*
Non-Hispanic White	743 (12.75%)	639 (10.96%)	479 (8.22%)	396 (6.79%)
Hispanic	503 (8.63%)	374 (6.42%)	286 (4.91%)	213 (3.65%)
Non-Hispanic Black	344 (5.90%)	317 (5.44%)	340 (5.83%)	341 (5.85%)
Other	345 (5.92%)	221 (3.79%)	154 (2.64%)	134 (2.30%)
Education					<0.001*
Less than HS	250 (4.29%)	252 (4.32%)	236 (4.05%)	248 (4.25%)
HS or GED	362 (6.21%)	366 (6.28%)	349 (5.99%)	317 (5.44%)
Some college	621 (10.65%)	513 (8.80%)	407 (6.98%)	379 (6.50%)
College or above	702 (12.04%)	420 (7.21%)	267 (4.58%)	140 (2.40%)
Continuous measures (mean (SD))
HEI-2015 scores	60.02 (12.98)	53.14 (12.22)	50.03 (11.77)	44.38 (11.67)	<0.001*
E-DII scores	−0.86 (1.91)	0.18 (1.64)	0.69 (1.60)	1.36 (1.53)	<0.001*
Age	50.70 (16.67)	51.02 (17.67)	51.17 (17.65)	51.27 (17.94)	0.8106
BMI	29.29 (6.99)	29.95 (7.19)	30.72 (7.61)	30.78 (7.90)	<0.001*
Family income-to-poverty ratio	2.93 (1.63)	2.60 (1.58)	2.39 (1.52)	2.08 (1.44)	<0.001*

*Significance indicated by a p < 0.05.

DII: Dietary Inflammatory Index; Q1–Q4: quartile 1–quartile 4; HS: high school; GED: General Educational Development; HEI-2015: Healthy Eating Index-2015; E-DII: Energy-Adjusted Dietary Inflammatory Index; BMI: body mass index.

Table 3. Bivariate analyses by E-DII quartiles among participants from the National Health and Nutrition Examination Survey 2015–2018.

E-DII quartiles
N = 5289 total sample	Q1: n = 1500 (25.7%)	Q2: n = 1367 (23.5%)	Q3: n = 1404 (24.1%)	Q4: n = 1558 (26.7%)	p Value
E-DII quartile range	−5.8 to −1.09	−1.10 to 0.35	0.36–1.56	1.57–4.36	–
Categorical measures (n (% per total sample))
Gender					<0.001*
Males	589 (10.10%)	685 (11.75%)	730 (12.52%)	839 (14.39%)
Females	911 (15.63%)	682 (11.70%)	674 (11.56%)	719 (12.33%)
Race/Ethnicity					<0.001*
Non-Hispanic White	523 (8.97%)	505 (8.66%)	569 (9.76%)	660 (11.32%)
Hispanic	404 (6.93%)	373 (6.40%)	264 (4.53%)	264 (4.53%)
Non-Hispanic Black	247 (4.24%)	270 (4.63%)	488 (8.37%)	488 (8.37%)
Other	326 (5.59%)	219 (3.76%)	146 (2.50%)	146 (2.50%)
Education					<0.001*
Less than HS	245 (42.16%)	244 (4.19%)	243 (4.17%)	254 (4.36%)
HS or GED	253 (4.34%)	301 (5.16%)	378 (6.48%)	462 (7.93%)
Some college	445 (7.64%)	427 (7.33%)	477 (8.18%)	571 (9.80%)
College or above	557 (9.56%)	395 (6.78%)	306 (5.25%)	271 (4.65%)
Continuous measures (mean (SD))
HEI scores	66.65 (10.69)	56.27 (9.41)	49.34 (8.77)	40.75 (8.76)	<0.001*
DII scores	−1.46 (1.51)	−0.60 (1.58)	−0.12 (1.60)	0.65 (1.71)	<0.001*
Age	53.43 (17.56)	52.22 (16.87)	50.21 (17.13)	48.28 (17.50)	<0.001*
BMI	28.88 (6.91)	29.89 (7.06)	30.52 (7.43)	30.89 (7.89)	<0.001*
Family income-to-poverty ratio	2.85 (1.64)	2.65 (1.61)	2.52 (1.57)	2.27 (1.48)	<0.001*

*Significance indicated by a p < 0.05.

E-DII: Energy-Adjusted Dietary Inflammatory Index; Q1–Q4: quartile 1–quartile 4; HS: high school; GED: General Educational Development; HEI-2015: Healthy Eating Index-2015; DII: Dietary Inflammatory Index; BMI: body mass index.

Table 4. Multiple Linear regression analyses between HEI, DII and E-DII with and without covariates among 5829 participants from the National Health and Nutrition Examination Survey 2015–2018.

Unadjusted DII model^a (adjusted R^2= 17%)
	β (SE)	95% Confidence Interval	p vs. Referent
DII*
Quartile 1	Referent	–	–
Quartile 2	−7.45 (0.54)	−14.37 to −0.53	0.046*
Quartile 3	−10.61 (0.85)	−21.46 to 0.25	0.051
Quartile 4	−15.99 (1.76)	−38.35 to 6.37	0.070
Unadjusted E-DII model^b (adjusted R^2= 51%)
E-DII**
Quartile 1	Referent	–	–
Quartile 2	−9.33 (0.77)	−19.17 to 0.51	0.51
Quartile 3	−16.56 (0.65)	−24.85 to −8.26	0.025*
Quartile 4	−24.93 (0.87)	−36.04 to −13.83	0.022*
Adjusted DII model^c (adjusted R^2= 26%)
DII*
Quartile 1	Referent	–	–
Quartile 2	−7.70 (0.74)	−17.08 to 1.70	0.061
Quartile 3	−10.68 (0.82)	−21.10 to −0.26	0.049*
Quartile 4	−16.07 (0.46)	−34.98 to 2.84	0.059
Adjusted E-DII model^d (adjusted R^2= 53%)
E-DII**
Quartile 1	Referent	–	–
Quartile 2	−9.14 (0.64)	−17.30 to −0.97	0.045*
Quartile 3	−15.76 (0.44)	−21.37 to −10.15	0.018*
Quartile 4	−23.77 (0.58)	−31.18 to −16.36	0.016*

*Significance indicated by a p < 0.05.

^aUnadjusted DII model: HEI-2015 and DII by quartile.

^bUnadjusted E-DII model: HEI-2015 and E-DII by quartile.

^cAdjusted DII model: HEI-2015, DII by quartile, gender, race/ethnicity, education, age, BMI, family income-to-poverty ratio.

^dAdjusted E-DII model: HEI-2015, E-DII by quartile, gender, race/ethnicity, education, age, BMI, family income-to-poverty ratio.

DII quartile ranges: 1= −4.77 to −1.31; 2= −1.32 to 0.02; 3 = 0.03–1.38; 4 = 1.39–4.52.

E-DII quartile ranges: 1= −5.80 to −1.09; 2= −1.10 to 0.35; 3 = 0.36–1.56; 4 = 1.57–4.36.

HEI-2015: Healthy Eating Index-2015; DII: Dietary Inflammatory Index; E-DII: Energy-Adjusted Dietary Inflammatory Index.

Data availability statement

Data sharing is not applicable to this article as no new data were created or analyzed in this study.