Development of a semi-quantitative food frequency questionnaire for middle-aged inhabitants in the Chaoshan area, China

Table 1 Characteristics of the investigated subjects

	Males		P	Females		P
	Rural	Urban		Rural	Urban
	n = 115	n = 102		n = 102	n = 98
Age (yr)	43.1 ± 6.9	42.4 ± 7.1	0.803	42.9 ± 6.8	41.3 ± 7.7	0.245
Height (cm)	169.7 ± 6.0	170.3 ± 3.7	0.496	158.6 ± 4.2	158.6 ± 4.4	0.417
Weight (kg)	62.0 ± 6.4	65.9 ± 6.8	0.004	53.5 ± 6.3	53.8 ± 6.9	0.175
BMI	21.8 ± 2.2	22.6 ± 2.3	0.003	20.9 ± 2.4	21.5 ± 2.4	0.072

Table 2 Intake of nutrients by the urban and rural subjects

	Males		P	Females		P
	Rural	Urban		Rural	Urban
	n = 115	n = 102		n = 102	n = 98
Energy (kcal)	2 268 ± 539	2 237 ± 520	0.447	2 560 ± 661	2 449 ± 635	0.084
Protein (g)	83.5 ± 26.7	85.5 ± 23.8	0.375	85.0 ± 27.4	91.8 ± 27.3	0.244
Fat (g)	84.7 ± 28.2	90.8 ± 41.8	0.196	103.9 ± 26.9	104.3 ± 40.5	0.121
Carbohydrate (g)	295.1 ± 106.8	271.9 ± 101.1	0.320	327.2 ± 129.8	301.3 ± 111.8	0.758
Crude fiber (g)	10.2 ± 4.7	10.0 ± 3.7	0.707	9.5 ± 3.6	12.0 ± 9.8	0.017
Cholesterol (mg)	389.1 ± 221.0	352.7 ± 165.2	0.174	344.7 ± 249.8	441.3 ± 217.7	0.004
Carotene (μg)	2 576.7 ± 2 105.7	2 693.8 ± 2 009.1	0.675	2566.5 ± 2132.6	3 487.0 ± 1 872.2	0.001
Retinol (μg)	118.0 ± 84.0	116.6 ± 118.8	0.92	90.4 ± 78.6	137.1 ± 86.5	0.000
Folic acid (mg)	395.6 ± 219.9	357.6 ± 129.9	0.128	375.5 ± 155.0	452.6 ± 172.3	0.001
Vitamin C (mg)	88.4 ± 52.3	80.4 ± 39.6	0.205	96.2 ± 61.0	102.2 ± 38.8	0.416
Vitamin E (mg)	22.7 ± 10.8	27.0 ± 11.7	0.005	24.2 ± 10.9	28.9 ± 11.1	0.003
Calcium (mg)	525.6 ± 191.7	446.8 ± 190.2	0.412	406.9 ± 187.4	505.0 ± 155.1	0.000
Phosphorus (mg)	963.9 ± 311.0	937.2 ± 216.8	0.468	1 042.0 ± 390.2	1 099.8 ± 222.0	0.202
Potassium (mg)	1 718.0 ± 575.5	1 745.0 ± 459.3	0.705	1 808.9 ± 666.6	2 006.6 ± 453.2	0.015
Sodium (mg)	4 584.7 ± 1 856.1	4 460.9 ± 2 297.6	0.66	6 091.1 ± 2 436.2	4 733.4 ± 1 590.2	0.000
Magnesium (mg)	298.8 ± 93.4	280.2 ± 63.2	0.09	311.4 ± 104.2	326.7 ± 64.4	0.215
Iron (mg)	23.3 ± 8.8	22.9 ± 7.3	0.744	22.7 ± 8.2	25.5 ± 6.8	0.009
Zinc (mg)	12.73 ± 4.78	11.53 ± 2.80	0.028	13.25 ± 5.42	13.99 ± 3.54	0.256
Selenium (μg)	64.92 ± 29.60	69.40 ± 37.20	0.322	77.81 ± 42.63	72.55 ± 38.14	0.36
Copper (mg)	2.46 ± 1.53	2.24 ± 1.02	0.227	2.30 ± 1.19	2.38 ± 0.68	0.589
SFA (g)	21.14 ± 7.51	22.83 ± 7.92	0.107	24.12 ± 10.56	25.84 ± 8.78	0.215
MUFA (g)	32.05 ± 10.68	35.83 ± 10.47	0.009	36.53 ± 15.36	42.34 ± 10.26	0.002
PUFA (g)	18.62 ± 8.27	23.01 ± 9.70	0.000	21.90 ± 15.58	26.41 ± 8.92	0.013
Oleic acid (g)	29.40 ± 9.79	33.12 ± 9.76	0.005	33.50 ± 13.74	38.46 ± 9.39	0.003
Linoleic acid (g)	16.76 ± 7.41	20.89 ± 8.76	0.000	18.93 ± 8.63	23.92 ± 8.12	0.000
Linolenic acid (g)	1.64 ± 1.30	1.67 ± 1.46	0.895	1.74 ± 1.62	2.76 ± 2.06	0.000
Arachidonic acid (g)	0.088 ± 0.041	0.087 ± 0.041	0.951	0.092 ± 0.056	0.096 ± 0.047	0.626
EPA (g)	0.038 ± 0.046	0.039 ± 0.036	0.900	0.050 ± 0.041	0.034 ± 0.032	0.004
DHA (g)	0.079 ± 0.100	0.069 ± 0.063	0.385	0.118 ± 0.095	0.072 ± 0.073	0.000

SFA: saturated fatty acid; MUFA: mono-unsaturated fatty acid; PUFA: poly-unsaturated fatty acid; EPA: eicosapentaenoic acid; DHA: docosahexaenoic acid.

Table 3 Numbers of foods contributing to 29 nutrients with up to 90 cumulative % and 0.9 cumulative r²

	Cumulative %			Cumulative r2
	Rural	Urban	Combined	Rural	Urban	Combined
Energy	49	51	60	33	22	37
Protein	79	85	94	51	26	55
Fat	23	23	25	150	11	17
Carbohydrate	26	29	33	3	8	77
Crude fiber	65	61	74	74	13	21
Cholesterol	31	36	37	47	10	12
Carotene	23	21	38	47	12	8
Retinol	25	30	33	28	7	55
Folic acid	53	49	59	40	13	19
Vitamin C	38	27	44	52	17	70
Vitamin E	48	45	54	116	5	16
Calcium	94	93	104	70	19	30
Phosphorus	85	91	102	41	28	51
Potassium	114	99	120	63	36	1
Sodium	13	16	16	145	4	3
Magnesium	86	98	109	41	31	58
Iron	84	94	104	45	22	35
Zinc	72	78	86	41	15	44
Selenium	73	88	96	82	8	22
Copper	76	75	88	91	9	31
SFA	22	22	36	100	10	14
MUFA	16	17	21	70	9	8
PUFA	18	16	23	138	5	113
Oleic acid	15	15	17	142	6	8
Linoleic acid	17	15	18	143	5	8
Linolenic acid	31	28	56	136	1	2
Arachidonic acid (g)	24	32	53	53	17	17
EPA	22	32	51	30	17	23
DHA	14	29	36	24	13	12
Mean	46	48	58	72	14	30

SFA: saturated fatty acid; MUFA: mono-unsaturated fatty acid; PUFA: poly-unsaturated fatty acid; EPA: eicosapentaenoic acid; DHA: docosahexaenoic acid.

Table 4 Percentage contributions of the top five foods for energy and protein

Energy						Protein
Rural		Urban		Combined		Rural		Urban		Combined
Rice	45.8	Rice	38.2	Rice	41.9	Rice	28.6	Rice	23.6	Rice	25.7
Pork	7.7	Peanut oil	8.9	Peanut oil	7.8	Pork	7.5	Pork	6.6	Pork	6.8
Peanut oil	6.9	Pork	6.9	Pork	7.1	Grass carp	3.4	Beef	4.0	Grass carp	3.6
Mixed oil	4.2	Mixed oil	6.4	Mixed oil	5.3	Egg	3.2	Grass carp	3.8	Egg	3.5
Lard	4.1	Lard	3.2	Lard	3.7	Fish	2.9	Egg	3.8	Beef	2.9

Table 5 Percentage contribution of the top five foods for fat and carbohydrate

Fat						Carbohydrate
Rural		Urban	Combined			Rural		Urban		Combined
Peanut oil	21.7	Peanut oil	24.2	Peanut oil	22.9	Rice	70.4	Rice	67.5	Rice	70.4
Pork	20.2	Mixed oil	17.6	Pork	17.4	Noodle	3.2	Noodle	3.3	Noodle	3.2
Mixed oil	13.3	Pork	15.7	Mixed oil	15.6	Bread	2.3	Bread	3.0	Bread	2.3
Lard	13.1	Lard	11.0	Lard	11.0	Rice noodles	1.7	Rice noodles	2.1	Rice noodles	1.7
Pork chops	3.7	Pork chops	3.6	Pork chops	3.6	White sugar	1.6	White sugar	1.9	White sugar	1.6

Table 6 Percentage coverage of nutrients by the SQFFQ

	% coverage
	Rural	Urban	Combined
Energy	94.3	94.2	93.7
Protein	91.7	90.1	88.4
Fat	95.0	93.5	93.8
Carbohydrate	94.3	95.4	94.6
Crude fiber	86.5	87.3	87.5
Cholesterol	93.3	88.9	86.3
Carotene	88.7	93.9	90.3
Retinol	91.8	81.7	89.1
Folic acid	91.5	92.8	92.5
Vitamin C	86.3	94.6	91.2
Vitamin E	89.7	88.3	89.4
Calcium	87.3	87.3	88.6
Phosphorus	92.4	90.5	86.4
Potassium	86.8	90.5	88.2
Sodium	97.7	96.1	95.1
Magnesium	89.7	90.9	90.1
Iron	83.5	90.3	89.6
Zinc	90.9	91.9	91.6
Selenium	86.6	83.7	85.8
Copper	87.9	86.8	87.4
SFA	94.7	90.5	92.6
MUFA	96.2	95.6	88.4
PUFA	91.1	91.7	97.6
Oleic acid	96.5	95.7	90.2
Linoleic acid	94.2	92.1	97.6
Linolenic acid	91.2	92.2	82.7
Arachidonic acid (g)	90.3	88.5	92.7
EPA	82.4	80.2	87.6
DHA	88.4	81.9	82.9
Mean	90.7	90.2	90.0

SFA: saturated fatty acid; MUFA: mono-unsaturated fatty acid; PUFA: poly-unsaturated fatty acid; EPA: eicosapentaenoic acid; DHA: docosahexaenoic acid.

Table 7 Comparison of percentage contributions of the top three foods for energy, protein, fat, and carbohydrates in urban and rural areas of Jiangsu, Chongqing and Chaoshan in China

Percentage contribution
Energy
Urban
Jiangsu	Rice	36.9	Salad oil	6.9	Flour	5.9
Chongqing	Rice	30.1	Rape oil	10.2	Pork	6.2
Chaoshan	Rice	45.8	Pork	7.7	Peanut oil	6.9
Rural
Jiangsu	Rice	39.5	Lard	14.2	Pork	5.3
Chongqing	Rice	32.1	Rape oil	12.2	Flour	7.7
Chaoshan	Rice	38.2	Peanut oil	8.9	Pork	6.9
Protein
Urban
Jiangsu	Rice	23.1	Pork	7.2	Egg	5.0
Chongqing	Rice	17.5	Horse bean	8.0	Pork	6.5
Chaoshan	Rice	28.6	Pork	7.5	Grass card	3.4
Rural
Jiangsu	Rice	34.4	Pork	6.5	Egg	4.3
Chongqing	Rice	20.4	Pork	7.4	Flour	7.0
Chaoshan	Rice	23.6	Pork	6.6	Beef	4.0
Fat
Urban
Jiangsu	Salad oil	22.1	Soybean oil	17.1	Pork	9.5
Chongqing	Rape oil	30.0	Pork	15.3	Salad oil	1.5
Chaoshan	Peanut oil	21.7	Pork	20.2	Salad oil	13.3
Rural
Jiangsu	Lard	45.8	Pork	16.4	Rape oil	11.7
Chongqing	Rape oil	32.3	Lard	13.5	Pork	12.2
Chaoshan	Peanut oil	24.2	Salad oil	17.6	Pork	15.7
Carbohydrate
Urban
Jiangsu	Rice	57.1	Flour	8.7	Noodle	2.9
Chongqing	Rice	55.1	Flour	10.3	Noodle	7.9
Chaoshan	Rice	73.7	Noodle	2.8	Bread	1.7
Rural
Jiangsu	Rice	59.6	Noodle	5.8	Corn	5.7
Chongqing	Rice	60.1	Flour	16.6	Peas	2.8
Chaoshan	Rice	67.5	Noodle	3.3	Bread	3.0