Name  Section  Date 
LAB 6.2: Determining a Target Body Weight

Complete this lab if the results of Lab 6.1 indicate that a change in body composition would be beneficial for your health and well-being. This lab will help you set a target body weight based on a goal for BMI or percent body fat. Remember, though, that a wellness lifestyle that includes a sensible diet and regular exercise is more important for most people than achieving any specific target weight. In addition, you may have other health risk factors that could affect your body composition goals. You may decide to choose a lifestyle goal for your body composition target instead of a specific BMI, percent body fat, or target body weight. For example, you may set goals of increasing physical activity and improving your diet, and then let your body composition change as a result. Choose an approach that best fits your goals and preferences.

Equipment
Calculator (or pencil and paper for calculations)

Preparation
Determine percent body fat and/ or calculate BMI as described in Lab 6.1. Keep track of height and weight as measured for these calculations.

Height: (in.)     Weight: (lbs.)

Instructions: Target Body Weight from Target BMI
Use the chart below to find the target body weight that corresponds to your target BMI. Find your height in the left column and then move across the appropriate row until you find the weight that corresponds to your target BMI. Remember, BMI is only an indirect measurement of body composition. It is possible to improve body composition without any significant change in weight. For example, a weight training program may result in increased muscle mass and decreased fat mass without any change in overall weight. For this reason, you may want to set alternative or additional goals, such as improving the fit of your clothes or decreasing your waist measurement.

<18.5
Underweight		 18.5-24.9
Normal		 25-29.9
Overweight		 30-34.9
Obesity (Class I)		 35-39.9
Obesity (Class II)		 40≤
Extreme
Obesity
BMI 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
Height Body Weight (pounds)
4' 10"   81 86   91 96 101 105 110 115   120 124 129 134 139   144 148 153 158 163   168 172 177 182 187   192
4' 11"   84 89   94 99 104 109 114 119   124 129 134 139 144   149 154 159 163 168   173 178 183 188 193   198
5'   87 92   97 102 108 113 118 123   128 133 138 143 149   154 159 164 169 174   179 184 190 195 200   205
5' 1"   90 95   101 106 111 117 122 127   132 138 143 148 154   159 164 169 175 180   185 191 196 201 207   212
5' 2"   93 98   104 109 115 120 126 131   137 142 148 153 159   164 170 175 181 186   191 197 202 208 213   219
5' 3"   96 102   107 113 119 124 130 136   141 147 153 158 164   169 175 181 186 192   198 203 209 215 220   226
5' 4"   99 105   111 117 122 128 134 140   146 152 157 163 169   175 181 187 192 198   204 210 216 222 227   233
5' 5"   102 108   114 120 126 132 138 144   150 156 162 168 174   180 186 192 198 204   210 216 222 229 235   241
5' 6"   105 112   118 124 130 136 143 149   155 161 167 174 180   186 192 198 205 211   217 223 229 236 242   248
5' 7"   109 115   121 128 134 141 147 153   160 166 173 179 185   192 198 204 211 217   224 230 236 243 249   256
5' 8"   112 118   125 132 138 145 151 158   165 171 178 184 191   197 204 211 217 224   230 237 244 250 257   263
5' 9"   115 122   129 136 142 149 156 163   169 176 183 190 197   203 210 217 224 230   237 244 251 258 264   271
5' 10"   119 126   133 139 146 153 160 167   174 181 188 195 202   209 216 223 230 237   244 251 258 265 272   279
5' 11"   122 129   136 143 151 158 165 172   179 187 194 201 208   215 222 230 237 244   251 258 265 273 280   287
6'   125 133   140 148 155 162 170 177   184 192 199 207 214   221 229 236 243 251   258 266 273 280 288   295
6' 1"   129 137   144 152 159 167 174 182   190 197 205 212 220   228 235 243 250 258   265 273 281 288 296   303
6' 2"   132 140   148 156 164 171 179 187   195 203 210 218 226   234 242 249 257 265   273 281 288 296 304   312
6' 3"   136 144   152 160 168 176 184 192   200 208 216 224 232   240 248 256 264 272   280 288 296 304 312   320
6' 4"   140 148   156 164 173 181 189 197   206 214 222 230 238   247 255 263 271 280   288 296 304 312 321   329

SOURCE: Ratings from the National Heart, Lung, and Blood Institute. 1998. Clinical Guidelines on the Identification, Evaluation, and Treatment of Overweight and Obesity in Adults. Bethesda, Md.: National Institutes of Health.

 

Current BMI        Target BMI        Target body weight (from chart)   

Alternative/additional goals:

Note: You can calculate target body weight from target BMI more precisely by using the following formula: (1) convert your height measurement to meters, (2) square your height measurement, (3) multiply this number by your target BMI to get your target weight in kilograms, and (4) convert your target weight from kilograms to pounds:

1. Height   in. x 0.0254 m/in. = height   m

2. Height   m x height   m =   m2

3. Target BMI   x height   m2 = target weight   kg

4. Target weight   kg x 2.2 lb/kg = target weight   lb


Instructions: Target Body Weight from Target Body Fat Percentages
Use the formula below to determine the target body weight that corresponds to your target percent body fat.

Current percent body fat   Target percent body fat   

 

Formula Example: 180-lb male,
current percent body fat of 24%, goal of 21%
1.To determine the fat weight in your body, multiply your current weight by percent body fat (determined through skinfold measurements and expressed as a decimal). 180 lb x 0.24 = 43.2 lb
2.Subtract the fat weight from your current weight to get your current fat-free weight. 180 lb - 43.2 lb = 136.8 lb
3.Subtract your target percent body fat from 1 to get target percent fat-free weight. 1 - 0.21 = 0.79
4.To get your target body weight, divide your fat-free weight by your target percent fat-free weight. 136.8 lb / 0.79 = 173 lb

 

Note: Pounds are used for this calculation, but weight can be expressed in either pounds or kilograms, as long as the unit of measurement is used consistently.

1. Current body weight   x percent body fat   = fat weight 

2. Current body weight   - fat weight   = fat-free weight   

3. 1 - target percent body fat   = target percent fat-free weight   

4. Fat-free weight   / target percent fat-free weight   = target body weight   

 

Setting a Goal
Based on these calculations and other factors (including heredity, individual preference, and current health status), select a target weight or range of weights for yourself.

Target body weight: