There’s a pretty simple formula that most people can easily understand when it comes to weight control: If your calorie intake is greater than your calorie expenditure, you will gain weight and visa versa. According to this understanding, it doesn’t matter what food source that calorie came from – all that matters is the numbers.
And, since this is such a straightforward concept, it has persisted for a long time. Indeed, many people have successfully managed their weight under the guidance of this principle for years.
Science, however, has changed the way we view – or should view – the broad topic of nutrition. In light of the most recent research, we have to ask does this dietary law still hold true? Are all calories created equal?
Breakdown and Absorption
The first thing to realize is that your body doesn’t process all foods the same. Heavily processed foods are essentially already broken down, making their calories more accessible to your body – even if that processing just means the cooking that you do home.
Studies have even found that fluffy foods, like bread and other baked goods, give up their calories more easily than things like nuts. In fact, it has been shown that things like almonds actually deliver about 20 percent fewer calories than they technically should simply because your body can’t break down the cell walls thoroughly enough to access that fuel.
Even when you get down to the specific macronutrients, there are significant differences in procedure. Carbohydrates are your body’s preferred fuel source and are broken down quickly for use. Fats, however, are a little more cumbersome – making it easier to store them away for emergencies or long-duration activity. While your body is capable of converting protein into fuel, the process is tricky and takes a long time – so it would rather just use proteins for building and repair projects. We’ll talk more about how this affects you in the next section.
Of course, there are also certain conditions that prevent people from properly absorbing the calories in their food.
As mentioned, the different macronutrients receive different treatment when they enter your system. Carbohydrates are met with a spike of insulin, which drives the new-found fuel into your cells for immediate use. If this happens too quickly, though, you’re blood sugar levels can drop too low and you’re left feeling tired, cranky and – most damagingly – hungry. Fat has a slight impact on insulin but not nearly to the same degree.
And the hormone hardly notices protein. The muscle-building-macro does have a large influence on levels of your hunger hormones, leptin and ghrelin, though – making you feel fuller even when you took in fewer calories.
The power of this has been shown in numerous studies that put subjects on diets that all have the same caloric intake but different nutrient make-ups. The combined findings are clear: high carb intakes will lead to greater weight gain, while high protein diets support weight loss.
It’s also important to note that there is usually a lot more in your food than just those three macronutrients and these additives could have huge impacts on your weight. Artificial sweeteners, in particular have shown themselves to be problematic. Though calorie-free, these chemicals have the ability to alter the bacteria residing in the human gut in ways that actually increases the amount of calories absorbed from food – leading to obesity, diabetes and heart disease.
Which brings out another interesting point: Gut health can change our metabolism, as well, for better or for worse.