Potentials and limitations of a food group-based algorithm to assess dietary nutrient intake of women in rural areas in Tanzania

Figures & data

Table 1. Description of the food groups in CIMI-algorithm.

	Food Group	Contributing food items (% contents of each food)
1.	Maize	Maize flour dry (100%)
2.	Bulrush millet	Bulrush millet dry (100%)
3.	Sorghum	Sorghum flour dry (100%)
4.	Fried Bakery	Chapatti, African Donuts, Bhajia -> all three food items have an average contribution of 33.33%
5.	Other cereals	Rice (60%), finger millet (20%), wheat (20%)
6.	Plantain, white roots and tubers	Cooked bananas (30%), cassava (25%), white sweet potatoes (25%), potatoes (20%)
7.	Nuts	Groundnuts (90%), cashew nuts (10%)
8.	Pulses	Beans (kidney), cowpeas, pigeon peas, green grams, chicken peas, soya beans, Bambara nuts, lablab beans (hyacinths beans) -> all eight food items have an average contribution of 12.5%
9.	Vitamin A rich vegetables and yellow tubers	Yellow sweet potatoes (60%), pumpkin (25%), carrots (15%)
10.	Green leafy vegetables	Ilende [Ceratotheca sesamoides] (25%), cowpea leaves (20%), Mugunda [Corchorus trilocularis] (10%), amaranth (10%), sweet potato leaves (10%), Chinese cabbage (10%), cassava leaves (5%), spinach (5%), pumpkin leaves (5%)
11.	Other vegetables	Tomatoes (30%), onions (30%), African eggplant (30%), eggplant (5%), green pepper (5%)
12.	Meat	Beef (50%), chicken (15%), goat (15%), lamb (15%), pork (5%)
13.	Organ meat	Beef tripe (60%), beef liver (40%),
14.	Eggs	Chicken egg boiled (50%), chicken egg fried (50%)
15.	Milk and milk products	Yogurt (55%), cow’s whole fat milk (40%), milk powder (5%)
16.	Fish (all types)	Sardines (40%), fish relish (30%), fried fish (20%), smoked fish (10%),
17.	Vitamin A rich fruits-A	Mangoes (50%), papaya (50%)
18.	Other fruits	Oranges (30%), watermelon (30%), ripe bananas (30%), pineapple (5%), avocado (5%)
19.	Red palm oil	Palm oil (100%)
20.	Other oils and fats	Coconut cream (60%), vegetable oil (40%)
21.	Added sugar/honey	Sugar (90%), honey (10%)
22.	Soft drinks	Carbonated drinks, Coca-Cola, fruit flavored drinks -> all three food items have an average contribution of 33.33%
23.	Beer/ local brews	Beer local grain (90%), beer commercial (5%), beer local-nonspecific (5%)

CIMI: Calculator of Inadequate Micronutrient Intake.

Table 2. Socio-demographic characteristics of women who participated in Scale-N and Trans-SEC surveys.

	All	Chamwino	Kilosa	p
Women, N	1010	479	531
Age [years]^a	37 (30, 45)	38 (30, 47)	36 (30, 44)	0.029
	19– 85	20 -85	19–81
Weight [kg]^a	53.4	52.9	53.8	0.221
	(48.0, 60.5)	(48.0, 59.9)	(47.9, 61.6)
	30.5– 112.4	30.5 - 99.0	34.4– 112.4
Height [cm]^a	154 (151, 158)	155 (152, 159)	154 (149, 157)	<0.001
	131–188	136– 188	131– 169
BMI [kg/m^2]^a	22.3 (20.5, 25.2)	22.1 (20.2, 24.4)	22.7 (20.7, 26.1)	<0.001
	14.4–47.4	14.4 - 40,0	14.8– 47.4
BMI <18.5, % (n)^b	6.8 (69)	8.4 (40)	5.5 (29)	0.001
18.5 < BMI < 25, % (n)^b	66 (667)	70 (334)	63 (333)
BMI ≥25, % (n)^b	27 (274)	22 (105)	32 (169)

Data are median (interquartile range), minimum-maximum^a and percentage (number)^b.

p-values: Mann-Whitney U or Chi Square test as appropriate.

Table 3. Comparison of means and medians of energy and nutrient intake calculated by CIMI and NutriSurvey in Chamwino and Kilosa district.

	N	CIMI			NutriSurvey			CIMI - NutriSurvey			Pearson R
		Mean	Median	IQR	Mean	Median	IQR	Mean	Median	IQR
Energy [kcal]	1010	1631	1574	1025, 2111	1565	1517	998, 1994	65.3	26.8	−49.1, 156.8	0.931
Chamwino	479	1230	1125	727, 1649	1230	1112	704, 1596	−0.4	9.8	−40.3, 56.5	0.936
Kilosa	531	1992	1904	1480, 2437	1868	1795	1415, 2288	124.5	92.3	−68.0, 296.8	0.903
Protein [g]	1010	40.1	34.5	21.7, 52.5	41.5	34.9	21.3, 54.3	−1.4	−1.4	−4.8, 3.6	0.898
Chamwino	479	27.5	23.9	14.8, 34.5	29.2	23.3	15.0, 35.5	–1.8	–1.5	–3.6, 0.4	0.887
Kilosa	531	51.5	45.4	32.9, 64.7	52.5	47.7	33.3, 65.0	–1.0	–0.7	–7.8, 7.0	0.876
Fat [g]	1010	44.4	32.5	16.4, 62.7	30.2	24.0	13.4, 39.6	14.1	5.9	0.5, 23.0	0.778
Chamwino	479	24.4	18.0	9.5, 30.5	21.6	15.8	9.2, 27.2	2.8	1.6	–1.3, 5.6	0.869
Kilosa	531	62.3	55.9	33.1, 81.1	38.0	33.4	21.7, 47.2	24.3	18.0	5, 38.5	0.707
Carbohydrates [g]	1010	257.6	247.1	149.3, 342.8	261.3	241.9	147.7, 353.9	–3.6	5.4	–24.2, 17.1	0.929
Chamwino	479	178.2	161.2	99.8, 231.6	173.8	149.1	94.7, 229.3	4.4	10.5	1.6, 18.1	0.891
Kilosa	531	329.3	316.8	245.7, 404.5	340.2	325.5	251.5, 417.6	–10.9	–12.8	–40.5, 16.6	0.899
RE [µg]	1010	515	384	115, 717	685	422	135, 904	–170	5.1	–342.1, 89.1	0.512
Chamwino	479	639	515	319, 782	894	663	343, 1196	–254	–7.5	–503.1, 90.5	0.492
Kilosa	531	402	195	70, 573	496	200	47, 562	–94.1	9.1	–100.9, 83.7	0.480
Vitamin B1 [mg]	1010	1.2	1.2	0.8, 1.6	1.1	1.0	0.6, 1.4	0.1	0.1	0, 0.3	0.832
Chamwino	479	1.1	1.0	0.8, 1.5	1.0	0.9	0.5, 1.3	0.1	0.1	0, 0.3	0.853
Kilosa	531	1.3	1.2	0.9, 1.6	1.1	1.1	0.7, 1.5	0.2	0.2	0, 0.3	0.808
Vitamin B2 [mg]	1010	1.1	1.0	0.6, 1.4	1.1	1.0	0.6, 1.5	0	0	–0.2, 0.1	0.768
Chamwino	479	1.1	1.0	0.7, 1.5	1.2	1.0	0.7, 1.5	–0.1	0	–0.1, 0.1	0.738
Kilosa	531	1.0	0.9	0.6, 1.4	1.1	0.9	0.6, 1.5	0	0	–0.3, 0.2	0.805
Vitamin B6 [mg]	1010	1.5	1.4	1.0, 2.0	1.5	1.4	0.9, 1.9	0	0	–0.2, 0.3	0.810
Chamwino	479	1.4	1.2	0.9, 1.8	1.4	1.1	0.8, 1.7	0	0.1	–0.2, 0.3	0.766
Kilosa	531	1.7	1.6	1.1, 2.0	1.7	1.5	1.1, 2.1	0	0	–0.1, 0.3	0.844
Folic acid [µg]	1010	289	255	176, 379	373	324	215, 481	–84.8	–46.5	–132.5, –7.1	0.773
Chamwino	479	251	217	159, 323	341	284	197, 449	–90.1	–50.5	–119.8, –17.4	0.778
Kilosa	531	322	303	202, 416	402	356	244, 534	–80.0	−45.1	−143.0, 11.7	0.775
Vitamin B12 [µg]	1010	0.7	0	0, 0	1.0	0	0, 0.4	–2.7	0	0, 0	0.715
Chamwino	479	0.3	0	0, 0	0.3	0	0, 0	0	0	0,0	0.705
Kilosa	531	1.1	0	0, 1.6	1.5	0	0, 1.8	–0.5	0	–0.3, 0	0.719
Vitamin C [mg]	1010	45.7	33.1	17.8, 61.5	39.5	19.9	4.2, 52.1	6.1	13.9	–4.4, 29.8	0.534
Chamwino	479	32.0	27.1	15.3, 42.4	33.4	9.2	1.5, 44.6	–1.4	12.4	–16.9, 26.9	0.318
Kilosa	531	58.0	47.1	26.0, 78.1	45.1	29.9	11.9, 55.9	12.9	16.4	–1.5, 34.7	0.685
Calcium [mg]	1010	434	369	237, 542	570	394	196, 749	–136	–43.8	–240.2, 113.4	0.534
Chamwino	479	517	459	309, 622	740	608	380, 945	–222.9	−163.7	–350.2, –22.8	0.771
Kilosa	531	360	300	188, 461	417	221	135, 439	–57.5	55.1	–83.6, 207.0	0.212
Iron [mg]	1010	25.2	21.8	14.1, 32.7	23.7	19.2	12.6, 29.0	1.5	0.7	–2.0, 5.8	0.775
Chamwino	479	31.9	29.0	20.0, 39.9	31.9	28.2	19.5, 43.0	0	0	–2.6, 3.8	0.872
Kilosa	531	19.1	16.7	10.9, 24.3	16.3	14.2	10.2, 19.8	2.8	2.0	–1.5, 7.7	0.428
Zinc [mg]	1010	9.1	7.1	5.3, 9.9	7.8	8.1	5.9, 11.3	–1.2	–0.9	–2.1, 0	0.838
Chamwino	479	8.4	7.6	5.3, 10.9	9.5	8.2	5.8, 12.2	–1.1	–0.9	–1.8, –0.3	0.895
Kilosa	531	7.3	6.9	5.2, 9.1	8.7	8.0	6.0, 10.7	–1.4	–1.0	–2.5, 0.2	0.745

N: Number; IQR: Interquartile range; RE: retinol equivalents; Pearson correlation: all p-values were <0.001.

Figure 1. Scatter plots (upper row) and Bland-Altman plots (lower row) of energy (A,B), protein (C,D), iron (E,F) and zinc (G,H) intake calculated by CIMI and NutriSurvey (NS). Scatter plots include predictive equations, vertical lines in the Bland-Altman plots represent the recommended nutrient intake values (RNI).

Table 4. Haemoglobin, iron status (iron stores, serum ferritin and soluble transferrin receptor) and serum retinol and zinc of the women who participated in the Scale-N survey.

	All	Chamwino	Kilosa	p
Women, N	666	333	333
Hb [g/L]^a	127 (118, 135)	131 (123, 139)	124 (113, 131)	<0.001
Hb <120g/L, % (n)^b	28 (187)	17 (56)	39 (131)	<0.001
Retinol [µmol/L]^a	1.3 (1.6, 2.0)	1.7 (1.3, 2.0)	1.3 (1.1, 1.6)	<0.001
Retinol <1.05, % (n)^b	7 (48)	6 (21)	8 (27)	0.369
Iron stores [mg/kg BW]^a	5.7 (3.9, 7.8)	6.3 (4.4, 8.2)	5.4 (3.0, 7.1)	<0.001
Iron stores <0, % (n)^b	7 (48)	5 (18)	9 (30)	0.072
SF <12 or sTfR >8.5^b	22 (147)	16 (54)	28 (93)	<0.001
Zinc [mg/L]^a	0.75 (0.68, 0.84)	0.73 (0.67, 0.82)	0.78 (0.70, 0.85)	0.001
Zinc <0.66 mg/L, % (n)^b	20 (132)	25 (82)	15 (50)	0.002

Hb: Haemoglobin; SF: serum ferritin; sTfR: soluble transferrin receptor.

Data are median (interquartile range)^a and percentage (number)^b.

P-values: Mann-Whitney U and Chi Square test, as appropriate.

Anaemia is defined as Hb <120 g/L, low retinol as retinol <1.05 µmol/L, negative iron stores as iron stores <0 mg/kg BW, iron deficiency as SF <12 µg/L and/or sTfR >8.5 mg/L and low zinc status as Zinc <0.66 mg/L.

Table 5. Prevalence of anaemia and vitamin A, iron and zinc micronutrient deficiencies in the Scale-N women depending on nutrient intake (vs. < and ≥ RNI) calculated by CIMI-algorithm and NutriSurvey.

	RE intake < RNI		RE intake ≥ RNI
Women % (n)	CIMI n = 412	NS n = 357	CIMI n = 254	NS n = 309
Anemia	31(126)**	29 (105)*	19 (47)	22 (68)
Retinol <1.05 µmol/L	8 (34)	7 (26)	6 (14)	7 (22)
SF < 12 and/or sTfR > 8.5	26 (106)*	26 (93)*	16 (41)	18 (54)
Zinc <0.66 mg/L	20 (81)	19 (68)	20 (51)	21 (64)
	iron intake < RNI		iron intake ≥ RNI
	CIMI n = 493	NS n = 522	CIMI n = 173	NS n = 144
Anemia	29 (145)**	29 (150)*	16 (28)	16 (23)
Retinol <1.05 µmol/L	8 (40)	8 (39)	5 (8)	6 (9)
SF < 12 and/or sTfR > 8.5	25 (121)*	24 (124)*	15 (126)	16 (23)
Zinc <0.66 mg/L	19 (91)	19 (101)	24 (41)	22 (31)
	zinc intake < RNI		zinc intake ≥ RNI
	CIMI n = 554	NS n = 499	CIMI n = 112	NS n = 167
Anemia	27 (151)	26 (129)	20 (22)	26 (44)
Retinol <1.05 µmol/L	8 (43)	7 (34)	5 (5)	8 (14)
SF < 12 and/or sTfR > 8.5	23 (127)	24 (118)	18 (20)	17 (29)
Zinc <0.66 mg/L	20 (113)	21 (104)	17 (19)	17 (28)

All data are presented in percentages and numbers in brackets.

P-values (Chi-square test): *<0.05, **<0.001.

Anaemia is defined as Hb <120 g/L, low retinol as retinol <1.05 µmol/L, iron deficiency as serum ferritin (SF) <12 µg/L and/or soluble transferrin receptor (sTfR) >8.5 mg/L and low zinc status as zinc <0.66 mg/L.

RNI: recommended nutrient intake: RE 500 µg/d, iron 29 mg/d (10% bioavailability), zinc 9.8 mg/d (low bioavailability) (De Carli et al. 2018).

De Carli E, Dias GC, Morimoto JM, Marchioni DML, Colli C. 2018. Dietary iron bioavailability: agreement between estimation methods and association with serum ferritin concentrations in women of childbearing age. Nutrients. 10(5):650. doi: 10.3390/nu10050650.

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