Introduction: Previous Icelandic studies have reported higher prevalence of obesity among women residing outside the capital area but no comparable information is available for men. The aim of this study was to assess diet and body mass index (BMI) of adult men and women residing within and outside the capital area.

Material and methods: Participants were 1312 men and women,18-80 years, from a random sample of the national registry, response rate 68.6%. Diet was assessed during years 2010 to 2011 using repeated 24-hour recall, weight and height self-reported. OR of BMI ≥25 kg/m² was calculated according to residence and education.  

Results:Women ≥46 years within the capital area had lower BMI, or 25.7 kg/m² vs 28.4 kg/m²p=0.007, and were less likely to have BMI ≥25 kg/m², OR=0.64; CI 0.41-1.0 than those outside the area. No difference was found between the areas among men or younger women. Diets outside the capital had higher percentage of total fat compared than inside the capital. Saturated fatty acid (SFA) were 15.7E% vs 13.9E% for men, p<0.001 and 14.8E% vs 14.0E%, p=0.007 for women and trans fatty acids (TFA) were 0.9E% vs 0.7E% p<0.001 and 0.8E% vs 0.7E% p=0.001 for men and women respectively.

Conclusions: Women‘s BMI is less associated with residence than in former Icelandic studies. Men‘s BMI is not associated with residence. Diets within the capital area are closer to recommended intake compared with diets outside the area.

Table I. Charateristics and nutrient intake of men and women by residence
			Women
			Within capital area		Outside capital area					p-value1
			n=413		n=267
Age, mean (sd)			47.6(16.2)		46.9(15.7)					0.55
Physical activity, hrs/wk, mean(sd)			3.5(3.4)		3.6(3.0)					0.93
Height, cm, mean(sd)			167.0(5.5)		166.8(6.0)					0.54
Alcohol, g/day, mean(sd)			4.5(10.5)		4.1(10.8)					0.30
Smoking, %			18.6		18.4					0.92
University eduacation, %			40.0		25.1					<0.001
Energy intake, kcal/day, mean(sd)			1739.0(492.3)		1810.0(571.3)					0.09
Protein, %E, mean(sd)			17.6(4.3)		17.6(4.3)					0.91
Total fat, %E, mean(sd)			35.2(7.0)		36.8(7.2)					0.004
SFA2, %E, mean(sd)			14.0(3.5)		14.8(3.9)					0.007
Cis-PUFA3, %E, mean(sd)			5.9(2.4)		6.0(2.6)					0.61
Trans FA4, %E, mean (sd)			0.70(0.3)		0.80(0.4)					0.001
Carbohydrate,%E, mean(sd)			43.7(7.5)		42.5(7.3)					0.04
Added sugar, %E, mean(sd)			8.9(6.1)		8.5(5.8)					0.46
Fiber, %E, mean(sd)			1.8(0.6)		1.7(0.6)					0.13
			Men
			Within capital area		Outside capital area					p-value1
			n=384		n=248
Age, mean(sd)			45.8(15.8)		47.9(17.0)					0.12
Physical activity, hrs/wk, mean(sd)			4.0(3.4)		3.6(3.7)					0.19
Height, cm, mean(sd)			181.5(6.4)		180.8(6.9)					0.22
Alcohol, g/day, mean(sd)			8.8(21.8)		8.6(21.6)					0.13
Smoking, %			14.1		18.1					0.17
University education, %			38.0		13.3					<0.001
Energy intake, kcal/day, mean(sd)			2335.0(754.5)		2433.9(809.3)					0.12
Protein, E%, mean(sd)			18.6(4.9)		18.5(4.5)					0.76
Total fat, E%, mean(sd)			35.8(7.2)		38.0(7.7)					<0.001
SFA2, E%, mean(sd)			13.9(3.9)		15.7(4.4)					<0.001
Cis-PUFA3, E%, mean(sd)			6.1(2.6)		5.6(2.3)					0.009
Trans FA4, E%, mean(sd)			0.73(0.34)		0.91(0.4)					<0.001
Carbohydrate, E%, mean(sd)			41.7(7.7)		40.0(8.6)					0.01
Added sugar, E%, mean(sd)			9.0(6.2)		9.2(6.9)					0.67
Fiber, E%, mean(sd)			1.5(0.6)		1.4(0.5)					<0.001
1T-test for normally distributed variables. Mann-Whitney U test for not normally distributed variables, Chi-square test for dual variables 2Saturated fatty acids, 3Cis-Polyunsaturated fatty acids, 4Trans fatty acids
Table II. Mean BMI and percent of women and men with BMI ≥ 25, by residence and age*
		Within capital area						Outside capital area
	n	BMI		% BMI ≥ 25			n	BMI	% BMI ≥25			p-value1		p-value2
		mean             (sd)						mean             (sd)
Women 18-45 yrs	186	25.3(5.0)		41.8			124	25.7(4.8)	43.4			0.50		0.77
Men 18-45 yrs	198	26.4(3.8)		55.6			107	26.6(4.3)	56.5			0.62		0.88
Women ≥ 46 yrs	208	25.7(4.8)		47.9			138	28.4(4.0)	60.1			0.007		0.03
Men ≥ 46 ára	182	27.9(4.2)		73.1			128	27.2(4.7)	78.6			0.37		0.26
1 for mean BMI, T-test
2 for % BMI ≥ 25, chi-square test *BMI: Body Mass Index

 

Table III. Odds ratio for people residing within capital area having BMI≥ 25
compared with those outside capital
	n	Unadjusted		Model A1		Model B2
		OR (95% CI)*		OR (95% CI)		OR (95% CI)
All 18-80 yrs	742	0.78(0.63;0.98)		0.78(0.62;0.99)		0.78(0.62;0.99)
Women 18-80 yrs	325	0.76(0.55;1.03)		0.74(0.54;1.01)		0.76(0.55;1.04)
Men 18-80 yrs	417	0.80(0.57;1.13)		0.82(0.58;1.17)		0.79(0.54;1.10)
All 18-45 yrs	308	0.98(0.71;1.35)		0.94(0.68;1.31)		0.96(0.68;1.34)
Women 18-45 yrs	137	0.93(0.60;1.47)		0.95(0.60;1.51)		0.97(0.61;1.56)
Men 18-45 yrs	171	0.96(0.60;1.55)		0.86(0.52;1.42)		0.84(0.50;1.41)
All ≥ 46 yrs	434	0.65(0.47;0.89)		0.64(0.46;0.89)		0.66(0.47;0.92)
Women ≥ 46 yrs	188	0.61(0.40;0.94)		0.61(0.39;0.94)		0.64(0.41;1.00)
Men ≥ 46 yrs	246	0.74(0.44;1.25)		0.73(0.43;1.24)		0.76(0.44;1.34)
1 Adjusted for age, physical activity, smoking, alcohol intake
2Additionally adjusted for eduaction
* Odds ratio, CI: Confidence interval

 

Table IV. Odds ration for university educated people having BMI ≥ 25 compared
with people with elementary school education
	n	Unadjusted		Model A1		Model B2
		OR (95% CI)*		OR (95% CI)		OR (95% CI)
Women 18-80 yrs	325	0.70(0.48;1.01)		0.80(0.54;1.19)		0.88(0.59;1.33)
Women 18-45 yrs	137	0.97(0.55;1.71)		0.71(0.37;1.39)		0.76(0.38;1.51)
Women ≥ 46 yrs	188	0.61(0.37;1.00)		0.75(0.42;1.33)		0.84(0.47;1.50)
Men 18-80 yrs	417	1.46(0.91;2.33)		1.28(0.77;2.13)		1.25(0.72;2.16)
Men 18-45 yrs	171	2.08(1.10;3.96)		1.24(0.59;2.63)		1.15(0.52;2.53)
Men ≥ 46 yrs	246	0.79(0.36;1.70)		0.72(0.32;1.64)		0.71(0.29;1.80)
1Adjusted for age, physical activity, smoking, alcohol intake
2Additionally adjusted for residence * Odds ratio, CI: Confidence interval

 

Table Va. Food intake of women by residence, g/day.  Mean (sd)
	Women
	Within capital area	Outside capital area	p-value1	Difference, %
	n =  413	n= 267
Milk and milk products	247(185)	257(177)	0.51	4
Whole milk	36(85)	45(100)	0.42	26
Low fat milk	70(114)	82(121)	0.17	16
Skim milk	33(96)	28(86)	0.37	-15
Sweets	18(25)	14(24)	0.07	-20
Bread, total	86(52)	83(49)	0.44	-4
Whole grain bread, fiber ≥ 6%	23(30)	23(36)	0.22	-2
Cookies and cakes	39(50)	49(60)	0.02	26
Oat meal porridge	24(53)	30(64)	0.16	28
Pízza	23(58)	22(52)	0.79	-6
New potatoes	45(51)	59(57)	0.002	30
French fries	4(13)	5(14)	0.31	16
Pasta, cus-cus	15(38)	17(37)	0.53	15
Fruits and vegetables, total	255(167)	250(178)	0.70	-2
Fresh vegetables	105(91)	104(96)	0.91	-1
Fresh fruis and berries	128(117)	124(120)	0.73	-3
Fish and fish products	40(53)	35(40)	0.10	-14
Meat and meat products	88(63)	108(69)	<0.001	23
Highly processed meat	13(22)	18(32)	0.05	33
Butter and butter products	10(11)	11(12)	0.42	8
Margarine	3(4)	3(3)	0.45	-7
Vegetable oils	2(6)	2(6)	0.83	-5
Cod liver oil	2(3)	1(3)	0.27	-22
Water and carbonated water	770(550)	716(516)	0.20	-7
Carbonated water	61(174)	23(107)	<0.001	-63
Juice	95(138)	81(145)	0.22	-15
Coffee	245(253)	313(312)	0.003	28
Soft drinks	211(313)	194(325)	0.49	-8
Beer	24(114)	37(157)	0.27	50
Table wine	28(72)	19(68)	0.009	-33
1T-test for normally distributed variables. Mann-Whitney U test for not normally distributed variables

 

 

Table Vb. Food intake of men by residence, g/day.  Mean (sd)
	Men
	Within capital area	Outside capital area	p-value1	Difference, %
	n=384	n= 248
Milk and milk products	324(242)	397(296)	0.001	22
Whole milk	53(117)	120(228)	<0.001	128
Low fat milk	112(165)	120(199)	0.52	7
Skim milk	39(106)	27(95)	0.01	-30
Sweets	18(32)	14(27)	0.05	-25
Bread, total	107(68)	102(72)	0.45	-4
Whole grain bread, fiber≥6%	21(35)	18(32)	0.08	-18
Cookies and cakes	47(60)	60(82)	0.03	28
Oat peal porridge	29(81)	38(81)	0.06	34
Pízza	34(84)	30(73)	0.91	-12
New potatoes	68(75)	97(91)	<0.001	42
French fries	10(21)	10(24)	0.79	5
Pasta, cus-cus	29(58)	14(36)	<0.001	-53
Fruits and vegetables, total	236(167)	203(171)	0.02	-14
Fresh vegetables	113(90)	89(108)	0.004	-21
Fresh fruit and berries	98(114)	81(116)	0.08	-17
Fish and fish products	53(67)	57(80)	0.53	7
Meat and meat products	154(107)	188(139)	0.001	22
Highly processed meats	26(41)	32(59)	0.19	22
Butter and butter products	12(14)	17(18)	<0.001	42
Margarine	5(5)	4(5)	0.03	-18
Vegetable oils	2(4)	1(3)	0.02	-33
Cod liver oil	2(4)	2(4)	0.87	-2
Water and carbonated water	649(606)	488(498)	<0.001	-25
Carbonated water	53(166)	35(125)	0.13	-33
Juice	104(176)	65(126)	0.001	-38
Coffee	360(351)	473(527)	0.003	31
Soft drinks	283(362)	259(351)	0.41	-8
Beer	111(420)	131(419)	0.59	18
Table wine	26(84)	9(33)	0.02	-65
1T-test for normally distributed variables. Mann-Whitney U test for not normally distributed variables