Cooking Method Determines Calories

It seems there is more to it than calories in, calories out. A new study from Harvard proves cooking method to have an effect on energy balance.

Calories in, calories out. That’s all it takes to maintain, loose or gain weight, correct? Think again. Researchers from Harvard recently published the results of their study, Energetic consequences of thermal and nonthermal food processing, in the Proceedings of the National Academy of Sciences, and found that the amount of energy in food depends not only on the calorie content but how it’s prepared.  
 
Food’s energy value is sometimes measured before processing, but we know very well that the composition of the food, its vitamins, minerals, and even macronutrients are more or less bioavailable after the cooking process. Evolutionary biology researchers striving to understand our history and how cooking food played a big part in our evolution, looked into how different diets, raw vs cooked affected the body composition of mice.  
 
The scientists fed two groups of mice either meat or sweet potatoes and prepared the items differently: whole or pounded, raw or cooked.  The researchers found that pounded meat and potatoes caused more weight gain than raw food. And that cooking increased weight the most. Cooking food boosts the amount of energy your body can get from it, it is more easily digested, and easily assimilated and stored (ie weight gain).

The extra calories that cooking makes available may have allowed the survival of humans with larger bodies and more complex brains, starting around two million years ago.  Evolutionary biologists had also long suspected that the human diet became significantly more energy rich in the past two million years due to changes in the human body that make it require more energy, according to Rachel Carmody, a graduate student specializing in human evolutionary biology, and cooking allowed humans to obtain more energy from a smaller quantity of food.
 
Packaged, processed and prepared foods may need to be revaluated for calorie, macronutrient and micronutrient quantities, after they are fully prepared.  Time spent sitting on the shelf should also be considered, as many nutrients are sensitive to time.