How AS Nutrition and Food Science marks split between Section A and the chosen essays, why naming the biological mechanism beats stating the outcome, and the quantitative benchmarks worth learning cold.
阅读时间 3 分钟更新于: 2026年9月3日
试卷概览
卷数
2
总分
160
考试时间
3小时
题型
9
试卷
时间
分数
题数
比重
题型
AS 1: Principles of Nutrition
1小时 30分钟
80
16
50%
Short recall and identification, Structured biochemical and nutritional descriptions, Contextual applied nutrition paragraphs, Extended essay, choose 2 of 3
AS 2: Diet, Lifestyle and Health
1小时 30分钟
80
11
50%
Tick-box and short objective recall, Structured analytical explanations, Evaluative and justification short responses, Extended evaluative essay, choose 3 of 4
评级
ABCDEU
计算器规定
Calculators are permitted and expected for the numerical questions in this subject, for example unit conversions, energy calculations, or Glycaemic Load. The standard JCQ rule applies: a calculator must not have any retrievable information stored in it, including saved formulae, notes or programs. You are responsible for clearing your calculator's memory before the exam, and you should switch on exam mode if your calculator has one rather than relying on the reset button, which does not clear stored data.
AO1: AO1: knowledge and understanding of the specified content (33%)
AO2: AO2: the ability to apply knowledge, understanding and skills in a variety of situations and to analyse problems, issues and situations using appropriate skills (50%)
AO3: AO3: the ability to gather, organise and select information, evaluate acquired knowledge and understanding, and present and justify an argument (17%)
用途: Get the total kilocalories in a food from its macronutrient breakdown, using the correct conversion factor for each macronutrient.
使用时机: For questions giving the grams of protein, carbohydrate, fat or alcohol in a food and asking for its total energy value.
步骤
Convert each macronutrient figure to kilocalories as you read it from the data given: protein grams times 4, carbohydrate grams times 4, fat grams times 9, alcohol grams times 7. Key each conversion as one continuous sequence and add the running total with the M+ key rather than writing each figure down and re-adding by hand.
考试提示: This is a live keystroke sequence performed during the exam using the conversion factors you have learned by heart. CCEA and JCQ rules do not allow any formula, note or program to be stored in the calculator beforehand. Clear the memory before the exam and use exam mode if your calculator has one.
Live BMI calculation and classification
用途: Get an accurate BMI figure from weight and height without a separate squaring step, which is where transcription errors happen.
使用时机: For questions giving a person's weight and height and asking for their BMI and classification.
步骤
Divide weight in kilograms by height in metres, then divide again by height in metres, as one continuous sequence: weight, divide, height, divide, height, equals. This avoids squaring height as a separate step, which is where transcription errors happen. Compare the result to the classification boundaries you have memorised, rather than anything stored in the calculator.
考试提示: Perform this calculation live from the figures printed in the exam paper. The BMI classification boundaries must be recalled from memory, not stored as a note or program in the calculator, which is not permitted under JCQ rules.
Live Glycaemic Load calculation
用途: Get the Glycaemic Load of a food from its GI value and the carbohydrate content of a portion.
使用时机: For questions giving a food's GI value and carbohydrate content per portion and asking for its Glycaemic Load.
步骤
Key the Glycaemic Load formula as a single sequence from the figures given: GI value, times, grams of carbohydrate per portion, divide, 100, equals. Check that your answer is a smaller number than the GI value alone, which confirms you divided rather than multiplied by 100 in error.
考试提示: Work this out live from data given in the question. No formula, template or prior working may be stored in the calculator's memory before the exam begins.
常见错误
1medium涉及分数: 2Carbohydrate
Confusing intrinsic sugars, held inside a plant cell, with free sugars, released or added, when classifying foods such as pure fruit juice and dried fruit.
如何避免: Ask whether the cell structure has been broken or removed. Juicing and drying release sugar from its cell structure, which is why both count as free sugars despite being fruit.
2medium涉及分数: 3Overweight and obesity
Confusing Glycaemic Index, the rate a food raises blood glucose, with Glycaemic Load, which factors in the actual carbohydrate content of a real portion.
如何避免: State the Glycaemic Load formula when it is relevant: GI multiplied by grams of carbohydrate per portion, divided by 100, and use it rather than GI alone when portion size matters.
3high涉及分数: 4Alcohol
Giving generic health advice instead of the precise physiological reason, for example telling pregnant women to avoid alcohol without mentioning organogenesis, miscarriage risk or fetal alcohol spectrum disorder.
如何避免: Replace advice-style sentences with mechanism sentences. Say what the alcohol does to fetal development, not just that it should be avoided.
4high涉及分数: 4Cancer
Listing food sources or lifestyle factors linked to a disease without explaining the underlying mechanism, for example stating that meat causes cancer without mentioning charring amines, haem-induced inflammation or N-nitroso compounds.
如何避免: For every risk factor you name, add one sentence on how it causes harm at a cellular or biochemical level.
5medium涉及分数: 2Nutrient requirements
Treating Dietary Reference Values as individual daily targets rather than population benchmarks derived from a distribution of need.
如何避免: State explicitly that a DRV describes a population, not a person, before you apply it to an individual case in the question.
6medium涉及分数: 2Nutrient requirements
Assuming the Estimated Average Requirement is a minimum threshold everyone must meet, rather than a median where half the population needs less and half needs more.
如何避免: Learn EAR as the middle of a range, not a floor, and use that definition whenever a question asks you to interpret it.
7high涉及分数: 2Fat
Failing to state exact numerical values or precise biochemical terms, for example not defining a monounsaturated fatty acid as one with a single carbon-to-carbon double bond.
如何避免: Attach a number or a precise structural term to every claim where the specification defines one, rather than describing it only in general words.
8high涉及分数: 3Overweight and obesity
Writing an evaluative essay on obesity or diet-related disease without the quantitative benchmarks the mark scheme expects, such as BMI of 30 or above, waist circumference of 94cm or more in men, or 150 minutes of weekly activity.
如何避免: Keep a short list of the key benchmark figures for this unit and work at least one into every extended essay you write.