SEAB Original-style practice: Two breakfast cereals are compared per 100 g. Cereal A has 1600\ kJ of energy and 25\ g of sugar; Cereal B has 1500\ kJ and 8\ g of sugar. Explain which is the healthier choice and why, and explain why values are often given per 100 g.

Cereal B is the healthier choice. Although the two have similar energy (1500 versus 1600\ kJ per 100\ g), Cereal B has much less sugar (8\ g versus 25\ g per 100\ g). A high sugar intake adds energy and raises the risk of tooth decay, weight gain and type 2 diabetes, so the lower-sugar cereal is the better everyday choice. Values are often given per 100\ g because it lets the consumer compare two products fairly on the same basis, regardless of the pack or serving size, since the serving sizes the manufacturers choose may differ. What markers reward: choosing Cereal B with the sugar comparison as the reason, a health link for high sugar, and the explanation that per 100\ g allows fair comparison between products.

SingaporeNutrition & Food ScienceSyllabus dot point

How do you read a nutrition information panel and use it to compare products and judge whether a food is healthy?

Interpret a nutrition information panel and use per-100g and per-serving values to compare and judge foods

A focused answer on nutrition information panels - reading energy and nutrient values per 100 g and per serving, comparing products, judging high and low amounts, and using Healthier Choice symbols.

Generated by Claude Opus 4.88 min answerUpdated 2026-06-06

Reviewed by: AI editorial process; not yet individually human-reviewed

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What this dot point is asking
The answer
Examples in context
Try this

What this dot point is asking

The syllabus wants you to read a nutrition information panel, use the per-100 g and per-serving figures, compare products, and judge whether a food is high or low in a nutrient. The central idea is that the panel turns vague impressions ("this seems healthy") into hard numbers you can compare, but only if you read the serving size and use per-100 g for fair comparisons.

The answer

What a nutrition information panel shows

A nutrition information panel lists the amounts of energy and key nutrients in the food, usually both per 100 g (or per 100 mL) and per serving. The nutrients shown typically include energy (in kJ and often kcal), protein, total fat, saturated fat, carbohydrate, sugars, dietary fibre and sodium (salt).

Per 100 g versus per serving

Per 100 g values let you compare two products fairly, because they are on the same basis regardless of pack or serving size. Use these to compare, for example, two cereals.
Per serving values tell you what you get in one portion as defined by the maker. These are useful for working out your own intake, but the serving size may be smaller than what people actually eat.

Always check the serving size: if you eat more than one serving, multiply the figures accordingly.

Judging high and low amounts

You can judge whether a food is high or low in a nutrient using the per-100 g figure and general guidance. As a rough guide, a food is "high" in fat, saturated fat, sugar or salt if it has a lot per 100 g, and "low" if it has little. High sugar, saturated fat and salt are the values to watch, because of their links to tooth decay, weight gain, heart disease and high blood pressure.

Healthier Choice symbols

In Singapore, the Healthier Choice Symbol helps consumers quickly spot products that are, for example, lower in sugar, fat or salt, or higher in fibre or wholegrain, compared with similar products. It is a quick guide, but reading the panel gives the full picture.

Comparing two yoghurts and checking real intake

A shopper compares two yoghurts and wants the lower-sugar one, then works out their intake. Yoghurt A has $12\ \text{g}$ sugar per 100 g; Yoghurt B has $5\ \text{g}$ per 100 g. The shopper eats a $150\ \text{g}$ tub of Yoghurt B. Work through it step by step.

Step 1: Compare per 100 g

Compare the sugar per 100 g: Yoghurt A has $12\ \text{g}$ and Yoghurt B has $5\ \text{g}$ . Using the same per-100 g basis, Yoghurt B is clearly lower in sugar and the healthier choice.

Step 2: Note why per 100 g is used

Per 100 g lets the two yoghurts be compared fairly even if their tub sizes differ, so the comparison is not distorted by serving size.

Step 3: Work out the real intake

The shopper eats $150\ \text{g}$ of Yoghurt B. Sugar eaten is $\dfrac{150}{100} \times 5 = 7.5\ \text{g}$ . Scaling the per-100 g figure to the actual amount eaten gives the true intake.

Step 4: Judge the result

At $7.5\ \text{g}$ of sugar for the tub, Yoghurt B is a sensible choice, much lower than Yoghurt A would have been. The shopper has used per 100 g to compare and the serving size to find their real intake.

Examples in context

Example 1. Choosing a lower-sugar drink. Comparing two bottled drinks per 100 mL shows which has less sugar, regardless of bottle size. A drink with a Healthier Choice symbol for lower sugar is a quick pick, but reading the panel confirms exactly how much sugar each contains, helping a consumer cut their sugar intake.

Example 2. The hidden cost of a big serving. A packet of chips may list a modest energy figure per 30 g serving, but eating the whole 90 g bag triples it. Checking the serving size against how much is really eaten reveals the true energy and salt intake, a common trap the panel helps avoid.

Try this

Cue. Explain why nutrition values are given per 100 g. Link it to allowing a fair comparison between products regardless of serving or pack size.
Cue. A food has $640\ \text{kJ}$ per $30\ \text{g}$ serving and a person eats $60\ \text{g}$ . Calculate the energy. Work out $2$ servings, so $2 \times 640 = 1280\ \text{kJ}$ .
Cue. State three nutrients on a panel that a health-conscious shopper should keep low. Recall sugar, saturated fat and sodium (salt).

Exam-style practice questions

Practice questions written in the style of SEAB exam questions on this dot point, with worked answer explainers. The year tag is the paper they imitate, not the source.

Original6 marksTwo breakfast cereals are compared per 100 g. Cereal A has

1600\ \text{kJ}

of energy and

25\ \text{g}

of sugar; Cereal B has

1500\ \text{kJ}

and

8\ \text{g}

of sugar. Explain which is the healthier choice and why, and explain why values are often given per 100 g.

Show worked answer →

Cereal B is the healthier choice. Although the two have similar energy ( $1500$ versus $1600\ \text{kJ}$ per $100\ \text{g}$ ), Cereal B has much less sugar ( $8\ \text{g}$ versus $25\ \text{g}$ per $100\ \text{g}$ ). A high sugar intake adds energy and raises the risk of tooth decay, weight gain and type 2 diabetes, so the lower-sugar cereal is the better everyday choice.

Values are often given per $100\ \text{g}$ because it lets the consumer compare two products fairly on the same basis, regardless of the pack or serving size, since the serving sizes the manufacturers choose may differ.

What markers reward: choosing Cereal B with the sugar comparison as the reason, a health link for high sugar, and the explanation that per $100\ \text{g}$ allows fair comparison between products.

Original5 marksA snack label states a serving is

30\ \text{g}

and provides

640\ \text{kJ}

per serving. A person eats

90\ \text{g}

. Calculate the energy they consume, and explain why reading per-serving values can be misleading.

Show worked answer →

Energy per serving is $640\ \text{kJ}$ for $30\ \text{g}$ . The person eats $90\ \text{g}$ , which is $90 \div 30 = 3$ servings. Energy consumed is $3 \times 640 = 1920\ \text{kJ}$ .

Per-serving values can be misleading because the manufacturer's serving size may be smaller than the amount people actually eat. A consumer who eats more than one serving takes in much more energy and nutrients than the per-serving figure suggests, so they should check the serving size and how much they really eat.

What markers reward: the correct calculation ( $3$ servings, $1920\ \text{kJ}$ ), and the explanation that small or unrealistic serving sizes understate the real intake.