It doesn’t matter if you’re trying to improve your overall health or just want to lose a few pounds – when you start talking about what you should eat, you’re bound to come across information about calorie limits. But do calorie limits matter? Isn’t eating healthy enough? Should you be limiting your calories, or do even calorie limits have their limits when it comes to achieving your health goals? Let’s break it down.
What really is a calorie, anyway?
Everything you eat contains calories. A specific unit of measurement, a calorie is how much energy the body can expect to receive from food. All calories equal 4.184 absolute Joules of energy regardless of whether they’re coming from cake, coffee, or carrots. But just because all calories hold the same amount of energy, it doesn’t mean that they’re all created equal. The body’s energy system is a complex process, and one that requires more than just calories to function properly.
So if all calories aren’t created equal, what’s the difference?
When it comes to how the body handles calories, it depends on where they come from. Calories from nutritionally-dense foods, such as fruits, vegetables, meats, and whole grains, break down differently than those from processed foods and refined sugars. So while you’re technically getting the same amount of energy from a candy bar, you’re getting much more nutritional value out of a banana. The macronutrients found in the foods you eat have a huge influence on your hormones, hunger, and eating behavior and can impact how your body processes and utilizes calories.
What are some of the factors that differentiate calories from one another?
Different calories metabolize in the body different ways. This means some calories end up being more fattening than others. For instance, calories from proteins—things like fish, lean red meat, and dairy products—take more energy to metabolize, so they end up being less fattening than calories from things like grains, which take longer to digest and use more energy to consume.
Another major impact on calorie consumption comes from the sugars glucose and fructose. Glucose is a simple sugar that’s found in starchy vegetables and pasta and can be metabolized by the whole body. Fructose is naturally found in fruit, but the American diet tends to be filled with large amounts of its concentrated form. Things like soda, processed foods, and baked goods are filled with high fructose corn syrup, agave, and crystalline fructose, which are only effectively metabolized by the liver. It’s also associated with increased risk of fatty liver disease and higher levels of ghrelin, the hormone that makes you feel hungry. So while both of these sugars provide the body with equivalent amounts of calories, fructose is harder on the body, less likely to be used, and doesn’t satisfy your hunger as much as glucose.
Certain calories, especially those from refined carbohydrates and processed foods, have a high glycemic index. When eaten, these calories are quickly absorbed and lead to a sharp increase in blood sugar, followed by a crash, which leads to sugar cravings. Whole, real foods have a low glycemic index, meaning the body absorbs them slowly, which makes you feel full for longer, helps curb cravings, and keeps your blood sugar regulated.
So, should you limit your calories?
In the end, that depends on your goals. It’s estimated that women should eat around 2,000 calories a day, while men need around 2,500. If you’re trying to lose weight, that number will drop and if you’re trying to gain weight, it increases. While your calorie intake can be cut, it should never drop below 1,200, as that’s what’s necessary to sustain optimum body function. The real key, though, is to make sure that if you do decide to cut your calories, the calories that you are getting are filled with the macronutrients your body needs, and come from healthy, real foods.