A new study published in the American Journal of Physical Anthropology has revealed that cooking might be releasing more calories from fat-rich foods.
Exploring the link between cooking & release of fats
The authors of the paper were motivated to analyse the link between cooking and fats in this regard because of the lack of research in this area.
The lead author, Emily Grooman, explains the purpose of their endeavour as follows:
“It’s been very well established that cooking starch- and protein-rich foods does increase the available calories you can get out of them. But when I began looking at the literature, no one had really examined the third major macronutrient, which is fat.“
The experiment: feeding mice
As part of their methodology, the scientists fed 20 mice with 4 different diets based on peanuts; the latter constitutes a fat-rich food. This lasted for several weeks.
The mice were divided into four groups, depending on the type of peanuts being served to them:-
- Raw and whole
- Raw and blended
- Roasted and whole
- Roasted and blended
The weight, food intake and exercise of each mouse were recorded.
Results: Obtaining more calories from the same amount of food
The results showed that the mice obtained more energy from the cooked peanuts than the raw ones. The researchers thus concluded that the mice extracted more calories from the same amount of food – cooking made all the difference.
Experiment: Examining faeces of mice
Thereafter, the faeces of the mice were examined. It was then found that the fats were digested to a greater extent when the peanuts were cooked, showing that the mice derived more energy when the food item was cooked as opposed to the case where the peanuts were raw.
Experiment: Analysing peanut cells
Analysing the cells of the peanuts shed further light. The rigid cell walls of the peanuts were modified through cooking such that they could release more fats from the cells. The otherwise inaccessible fats found in peanuts were thus tapped.
Cooking also impacts on the protein-coated structures known as oil bodies that store the fats and prevent digestion. The proteins known as oleosins that line the surface of the oil bodies are also changed through cooking, thereby making it easier for the fats to be freed.
Putting the new knowledge into practical applications
From the interpretation of the researchers, it appears that cooking enables us to reap more of what we consume. Furthermore, cooking might be used to tune the calorie content of processed foods so as that the energy requirements of the public are met, without going beyond the maximum.