Is a Calorie is a Calorie When Losing Weight? Not Quite…
When we think of weight loss, we think diet and exercise. The fundamental rule is that we create an energy deficit which therefore encourages weight loss. Simple enough right?
Of course there is always going to be a bit more to it than that. One thing of particular importance is that a calorie from one food isn’t going to necessarily equate to the same amount of energy digested from another food.
For example, let’s consider 20g of jelly beans (practically all glucose) and an apple. Both foods are high in sugar and both are approximately 80 calories (roughly 334 kJ), from about 20g of carbohydrate (in the form of sugar). But the net effect of the jelly beans will have a much greater impact in preventing your weight loss as compared to the apple.
Why is this so?
A jelly bean is predominantly glucose, a simple sugar that is naturally found in the blood stream. Our body breaks down carbohydrates into glucose in order to feed vital organs and muscles. When consuming a jelly bean, it’s already in a very simple form and therefore the body doesn’t really have to do all that much to digest the food. Think about it – minimal chewing is involved (which does expend energy) and then the stomach quickly and easily breaks this jelly bean down into a form that can be easily absorbed into the blood stream.
Conversely, an apple is comprised of a much more complex structure, full of fibre too. The apple is much more difficult to break down into your body. Much more chewing is involved and then the stomach has to work much harder to digest the apple for absorption into the body.
If we compare the glycaemic indexes (GI’s) of these two foods, you can easily see the contrast in the rate of absorption of both foods. A jelly bean will have a GI close to 100 (very fast to absorb), while an apple will have a low GI around 40 depending upon the variety and region of growth.
These GI’s, by definition, advise us that the 20g of carbohydrates are absorbed very rapidly in the jelly beans, in contrast to a very slow rate of absorption with the apple. The jelly bean sugars will be in your blood stream within an hour (give or take), while the apple will take about 2-3 hours. What this means is that the glycaemic load (GL) is much lower in the apple than in the jelly beans. A serving of food with a lower GL will be less likely to provide you with a surplus of calories at any point in time and instead provide a sustained release of energy into your body. Ultimately this means that it will be more effective for weight loss by avoiding fluctuations in energy being utilised by the body.
Although this is only just one example, the morale of this story is that a calorie from one food is not the same as a calorie from another food. Sure, it all ends up as energy, but it is very important to understand how foods will impact your body differently.
Generally speaking, you should be aiming to consume foods that are natural in nature. The more processed a food is, the more likely it is to be absorbed quickly into the body. Instead of confectionary, have whole grains or fruits. Instead of fatty fried foods, have seeds or nuts. And instead of highly processed deli meats, have some turkey or chicken breast. Not only will these foods contain better “quality” calories, they will also generally contain higher quality nutrients too. And of course ensure that your diet is well balanced with an array of foods including plenty of vegetables too!
