In glaring black-and-white block letters on the side of your favourite cereal, they vie for your attention — calories. Yet while they’re the most prominent part of a nutrition label, calories don’t tell the full story.

That’s according to registered dietitian and nutritionist Nichola Whitehead, who says the most important thing to look for on a nutrition label is not the calories, but rather the ingredients.

“It’s what you’re putting into your body that counts,” says Whitehead.

While calories can provide a very rough estimate of how healthy something might be, they leave out a number of important factors. Calories don’t tell you, for example, how satiated or full something is going to make you feel, how beneficial it is for your digestion, or whether it contains the vitamins and minerals you need for healthy skin, hair, and nails.

This guidance can be applied to whole meals as well as processed foods.

Take the following two breakfasts as an example. Meal one consists of a piece of wheat toast with butter, a couple scrambled eggs, and a coffee. Meal two includes a bowl of frosted cereal in low-fat milk, a glass of orange juice, and a coffee. Both meals have almost exactly the same number of calories.

While they tally up identically as far as their calories are concerned, the two plans are far from equal.

The cereal and juice meal is based around sugar and refined carbohydrates, which the body breaks down quickly, creating a constant need to refuel with caffeine or a snack. The eggs and wheat toast meal, on the other hand, is what Whitehead would call “balanced” — it contains the right mix of proteins and complex carbohydrates that your body needs to be properly fuelled in the long term.

Because they score high on something nutritionists refer to as the glycemic index, essentially a measure of how a food will impact your blood sugar levels, foods like processed cereals, white bread, and white rice fall into a category known as “empty calories.” Foods like this will “give you a rapid amount of sugar, but you’re going to feel hungry shortly afterwards,” says Whitehead.

This is where ingredients play a key role in sizing up the content of what you’re eating. When you see things like sugar, corn syrup, fructose, or white flour listed as the first ingredients on a food, that can be a good indicator that it’s not going to keep you full or energised in the long term. Instead, look for things like whole grains, lean proteins (chickpeas, beans, or chicken breast), and vegetables.

“It’s what kinds of foods you eat that matters when it comes to how healthy your body is, how satiated you’re feeling, and how much energy you’ve got,” says Whitehead. “Calories are just a tool.”

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