When trying to lose weight, a lot of people turn to calorie counting to make sure that they don’t eat more than their body needs, and that those extra calories don’t turn into extra fat in all the wrong places. While paying attention to your calorie intake is an important step to becoming conscientious about your diet and shedding pounds, the truth is that there’s actually more to this age-old calorie calculation than most people realize.
Cracking the Calorie Code
By definition, a calorie is just a unit of energy, measuring the amount of energy your body can get from eating particular types of food. According to the traditional school of nutritional thought, a calorie, no matter which food it comes from, can be counted just like any other calorie, always worth the same value. Standard calorie calculations are derived from basic calorie values assigned to proteins, carbs and fats. One gram of protein is calculated to contain 4 calories, 1 gram of carbohydrate contains 4 calories, and 1 gram of fat contains 9 calories. Based on these macro-nutrient food stats, the total calories in any meal could be easily calculated simply by knowing the number of grams of protein, carbs and fat in a meal.
Seems simple enough. But new research has realized that there’s more going on in this eating equation. It turns out that the way a food is processed and prepared can ultimately change the net calories that remain after you’ve digested your meal, and what’s left behind in your body for energy and fat storage.
The Role of Cooking on Calorie Counting
Here’s some strange food for thought: simply cooking a carrot makes it higher in calories. You’ve added nothing but heat – so where do those extra calories come from?
But if you think about all of the extra work your body has to do to digest that raw carrot – breaking down all of its tough fibers to get at its tiny essential nutrients – this quirky calorie calculation becomes a bit clearer. Digesting a raw food involves a lot more chewing, enzyme production, acid and fluid secretion, muscular contractions and other activities in your body, in order to chomp down, soften and dissolve its tougher, raw components. All of these digestion processes require the body to use up quite a bit of energy – which ultimately, burns up calories – to get the project done.
However, when a food has been cooked, the heat it has been exposed to already begins activating some of this food break-down process. In fact, you can think of cooked foods as pre-digested foods, in so far as some of the work that your body would have had to do to break down a raw food has already been done for it. That’s why, when you put a cooked food in your mouth, its usually softer, and easier for your body to chew and digest. And this means that, when you eat a cooked food rather than a raw one, your body has to do less work – and thus, burn up less calories – to digest it.
When the body does more digestion work, it burns up more calories, so that there are fewer calories left over after eating. However, when the body does less work to break down a food, it burns up fewer calories during the digestion process so that there are more net calories left over after eating.
The Role of Processing on Calorie Counting
A similar principle plays out when you eat whole foods instead of processed ones. Whole fruits, vegetables, nuts and seeds contain many tough, fibrous components that your body has to work through in order to access the nutritious parts of the plant. This forces your body to work hard and burn up calories in the act of breaking down these components, and then excreting them.
Processed and refined foods, on the other hand, have had most of the difficult-to-digest components removed from them before you purchased them, or are foods that have already been broken down and simplified during manufacture. This processing acts the same way cooking does – it pre-digests the food, minimizing the energy your body would have had to expend to break down the food in its natural, raw state, and thus leaving more calories behind at the end of digestion. This means that just the act of grinding a food can make it “higher in calories”, such as whole oats versus instant oatmeal powder.
Cooking and processing foods affect their caloric worth in other ways as well. Studies have shown that whole, unprocessed or minimally processed foods are ideal for keeping the friendly bacteria in your gut plentiful and healthy. Cooked and processed foods, on the other hand, can feed the “unfriendly” bacteria in your body, which leads to digestive upset, chronic health problems and weight gain. Moreover, the type of micro-flora living in your gut affects the entire digestion process, playing yet another factor on how many calories your body burns during digestion and how many are left over and stored as fat. That’s why, according to research, people who have a healthier community of micro-flora in their bodies tend to have less belly fat and lower BMIs than people who do not.
Emphasizing net calories after digestion – rather than only relying on how many calories a food contains before its eaten – could be a more accurate approach to assessing which foods are better for “fat burning” (foods that burn more calories during digestion) and your over-all health.
Of course, there are always exceptions to the rule. The nutritional properties of certain vegetables actually get enhanced from cooking (like tomatoes) or from processing (like garlic, which is healthier after it’s been chopped). Other foods, like certain squashes and grains, are difficult to digest and less palatable when raw. However, as a general rule, you should strive to eat the freshest fruits and veggies available to you, and opt for raw or minimal heat exposure (for example, opt to steam vegetables rather than boiling or baking, etc.). Meats, poultry and seafood should be properly cooked to avoid unsafe pathogens, but these, too, should be cooked using the minimum safest cooking temperatures and cooking times.