Weighing and tracking food can seem a bit overwhelming at first. It takes some time to build the habit of weighing and entering items. It additionally requires diligence to ensure that the food is indeed the correct nutritional representation of both amount and type within the selected tracking system. A common source of error is the weight difference between raw and cooked food. Raw vs. cooked food measurement error can lead to under-reporting or over-reporting energy intake versus actual intake. The impact can be significant – several hundred calories per day or more – if the same incorrect entry is repeated in frequently.
Raw vs. cooked food measurement – which is better?
Measurement of uncooked food is more precise and eliminates the risk of variance related to cooking procedures. That said, sometimes it’s more practical to weigh cooked. Here are a few practical rules of thumb to convert between them.
Meats, poultry, seafood, and potato LOSE ~ 25% water weight when cooked.
Whether broiled, baked, or sautéed, animal meat loses approximately 25% of its mass when cooked. As meat cooks, water is driven off (same applies for baked potato!). Only water is lost; the caloric and macronutrient values do not change despite the change in scale weight. Therefore 113 g/4 oz. raw meat is NOT equal to 113 g/4 oz. cooked from a calorie or macronutrient perspective because water has been eliminate in cooking.
This conversion table (shown in both ounces and grams) provides the estimated raw weight of meats based on the cooked weight. Knowing the cooked weight, it’s possible to back-calculate the raw weight equivalent by dividing the cooked weight by 0.75. This accounts for 25% water loss. It also works in the reverse. If you have the raw weight, multiply by 0.75 to get the cooked weight.
This is handy as an estimation for dining out. Say for example the entrée had a piece of grilled chicken breast and you want to estimate calories and macros in your tracker. If you received ~ 4 oz. of cooked chicken (using the palm of your hand as an estimate), you’d then find a validated entry for raw chicken breast and input the portion as 5.3 oz.
- 4 oz. raw chicken = 168 kcal, 21.7 g Protein, 6.3 g Fat, and 0 g carbs – incorrect entry for 4oz. cooked coked chicken
- 5.3 oz. raw chicken = 223 kcal, 32.5 g Protein, 9.4 g Fat, 0 g carbs – correct entry for 4oz. cooked chicken.
Rice, oats, pasta, and beans gain weight when cooked.
Cooking time and volume of water vary between these foods, but the following multipliers are a reasonable estimate to account for water gain. It’s the exact opposite circumstance as meat, the scale weight increases for the same calories and macros due to water weight.
Food weight tracking errors can add up over time if you frequently eat the same foods. I hope that this quick guide was helpful! Contact me if you need some assistance.