Hello,
I have a question regarding the calculation of BMI. I have in my data set the variables weight and height but when i calculate the BMI i get the wrong outcomes (big percentage underweight people for example). My question is, what am i doing wrong? Do i need to generate new variables for weight or height or something like that?
Thank you very much in advance!
The variable height (var452) is devided as follows:
And the variable weight (var453) is devided as follows:
The code i used to calculate the BMI is the following:
I have a question regarding the calculation of BMI. I have in my data set the variables weight and height but when i calculate the BMI i get the wrong outcomes (big percentage underweight people for example). My question is, what am i doing wrong? Do i need to generate new variables for weight or height or something like that?
Thank you very much in advance!
The variable height (var452) is devided as follows:
Code:
Lengte in cm | Freq. Percent Cum.
---------------+-----------------------------------
5 | 1 0.01 0.01
6 | 1 0.01 0.02
tot 52 cm | 1 0.01 0.02
58-62 cm | 1 0.01 0.03
63-67 cm | 1 0.01 0.04
68-72 cm | 10 0.08 0.12
73-77 cm | 7 0.05 0.17
78-82 cm | 1 0.01 0.18
83-87 cm | 1 0.01 0.19
88-92 cm | 3 0.02 0.21
93-97 cm | 1 0.01 0.22
98-102 cm | 6 0.05 0.27
103-107 cm | 43 0.34 0.60
108-112 cm | 187 1.47 2.07
113-117 cm | 550 4.32 6.39
118-122 cm | 940 7.38 13.77
123-127 cm | 1,274 10.00 23.77
128-132 cm | 1,035 8.12 31.89
133-137 cm | 1,048 8.23 40.11
138-142 cm | 757 5.94 46.06
143-147 cm | 313 2.46 48.51
148-152 cm | 201 1.58 50.09
153-157 cm | 212 1.66 51.75
158-162 cm | 595 4.67 56.42
163-167 cm | 903 7.09 63.51
168-172 cm | 1,361 10.68 74.19
173-177 cm | 1,001 7.86 82.05
178-182 cm | 1,014 7.96 90.01
183-187 cm | 725 5.69 95.70
188-192 cm | 309 2.43 98.12
193-197 cm | 129 1.01 99.14
198-202 cm | 30 0.24 99.37
203 cm of meer | 9 0.07 99.44
onbekend | 71 0.56 100.00
---------------+-----------------------------------
Total | 12,741 100.00
And the variable weight (var453) is devided as follows:
Code:
Gewicht in kg | Freq. Percent Cum.
---------------+-----------------------------------
3-7 kg | 4 0.03 0.03
8-12 kg | 3 0.02 0.05
13-17 kg | 4 0.03 0.09
18-22 kg | 3 0.02 0.11
23-27 kg | 2 0.02 0.13
28-32 kg | 1 0.01 0.13
33-37 kg | 3 0.02 0.16
38-42 kg | 9 0.07 0.23
43-47 kg | 48 0.38 0.60
48-52 kg | 249 1.95 2.56
53-57 kg | 542 4.25 6.81
58-62 kg | 1,211 9.50 16.32
63-67 kg | 1,411 11.07 27.39
68-72 kg | 1,756 13.78 41.17
73-77 kg | 1,590 12.48 53.65
78-82 kg | 1,710 13.42 67.07
83-87 kg | 1,279 10.04 77.11
88-92 kg | 1,048 8.23 85.34
93-97 kg | 633 4.97 90.31
98-102 kg | 488 3.83 94.14
103-107 kg | 234 1.84 95.97
108-112 kg | 143 1.12 97.10
113-117 kg | 73 0.57 97.67
118-122 kg | 50 0.39 98.06
123 kg of meer | 67 0.53 98.59
onbekend | 180 1.41 100.00
---------------+-----------------------------------
Total | 12,741 100.00
The code i used to calculate the BMI is the following:
Code:
gen bmi = (1000*var453/(var452*var452)) sum bmi gen underweight= 1 if bmi <=18.5 replace underweight = 0 if bmi >18.5 gen normal_weight= 1 if bmi >=18.5 | bmi <=24.9 replace normal_weight = 0 if bmi <18.5 | bmi >24.9 gen overweight= 1 if bmi >=25 | bmi <=29.9 replace overweight = 0 if bmi <25 | bmi >29.9 gen obese= 1 if bmi >= 30 replace obese = 0 if bmi <30 gen bmi_categories=0 replace bmi_categories= 1 if underweight==1 replace bmi_categories= 2 if normal_weight==1 replace bmi_categories= 3 if overweight==1 replace bmi_categories= 4 if obese==1 label define bmi 0 "Missing" 1 "Underweight" 2 "Normal Weight" 3 "Overweight" 4 "Obese" label values bmi_categories bmi tab bmi_categories
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