Meal prep changes calorie content
Boiling, frying, baking, chopping, blending, and other methods of food preparation can increase the calories available for absorption. For example, a large raw egg contains 72 kcal, hard-boiled 78 kcal, scrambled 84 kcal, and fried 98 kcal which is a 35% increase. Similarly, 100 g of potatoes contain 87 kcal if you boil them, 94 kcal if you bake them, and fries contain up to 316 kcal. When tracking calories in your cooking, make sure to look up caloric values for the cooking methods used, not just for the raw ingredients.
You don’t absorb all the calories you take in
In 1897 a scientist Wilbur Atwater made some experiments and estimated the caloric values of carbs, fat, and protein, and we have been using the 4-9-4 formula ever since. It says that 1 g of carbohydrate contains 4 kcal, 1 g of fat contains 9 kcal, and 1 g of protein contains 4 kcal. Now we are discovering that this formula works well for some foods, but not all. For example, we get only 68 % of the estimated calorie content of almonds and 79 % in case of walnuts. On the other hand, we are able to extract 128 % of the estimated calorie content of kale, 117 % from tomatoes, and 115 % from cooked black beans.
Despite the limitations of calorie counting mentioned in this series it can be a useful tool for weight loss. Just remember to always take the numbers with a grain of salt, calorie counting is not an exact science when we are talking about free living humans. But as long as it works for you and you have a follow up plan to keep the weight off, go for it.