CCFP priority topic 62 of 105
Loss of Weight on the CCFP exam
3 key features, the mistakes that cost marks, and a practice question.
Checked by a Canadian family physician, MD, CCFP. Updated October 20, 2026.
What the exam tests
Key features
The CFPC’s 3 key features for Loss of Weight. Each one below has how the exam asks it, the common mistakes and the approach.
Practice question
Try one before you read
A real case from the bank, in the new short-menu format. Answer it first. Then read the key features.
Key feature 1 of 3
Find the cause
When a patient loses weight for no clear reason, search for the cause step by step.
CFPC skill Clinical reasoningPhase Hypothesis generationSources Choosing Wisely Canada
On the exam
An older woman has lost weight on the office scale over several months. Expect a short menu (pick several from a list) of questions and first tests.
Pick what to ask and the first tests.
Common mistakes
A CT scan, scopes or tumour markers before the basic tests are back. Without a lead they find little. Skipping her medicines, mood and meals is the other miss.
Approach
- Confirm the loss first: two measured weights on the same scale. Then work out how much was lost, and over how long.
- Ask about appetite, chewing and swallowing, bowels, mood, memory and alcohol. Ask who shops and cooks, and whether money for food is short.
- Go through every medicine, including ones bought without a prescription. A drug that causes nausea, a bad taste or a dry mouth can cut intake.
- Examine head to toe, with the mouth and teeth, thyroid, lymph nodes, chest and abdomen. Add a short check of mood and memory.
- Start with basic blood and urine tests. Let the history, exam and those results choose any scan or scope.
- Fit the work-up to the patient's health, outlook and goals. Talk about what they want before you order more tests.
- In a teen, think of an eating disorder. If periods have stopped, test for pregnancy first. For celiac disease, send tissue transglutaminase immunoglobulin A (IgA), an antibody test, with a total IgA level. Save other antibodies for IgA deficiency.
Key feature 2 of 3
Keep true weights
Weigh patients the same way at each visit so you can tell when real loss has happened.
CFPC skill ProfessionalismPhase Physical
On the exam
A thin teen in a group home has a flat weight log from a bathroom scale. Expect a short menu (pick several from a list) of ways to weigh her.
Pick how to weigh and track her.
Common mistakes
Asking her own weight, or adding daily clothed weights. Neither is a measured baseline. Using the adult underweight cut-off at her age is wrong too.
Approach
- Weigh in a gown or light clothes, without shoes, in a private room.
- Use a checked (calibrated) scale, and the same scale each time. Write every weight in the chart with the date.
- In children and teens, plot weight, height and body mass index (BMI) on growth curves at each visit. Loss shows as a drop across the lines.
- Adult BMI cut-offs do not apply to children and teens. A growing teen can fall far below her own curve and still have a BMI that looks normal for an adult.
- Self-reported and home-scale weights are not a baseline. Clothes and an unchecked scale make them wrong.
- Albumin, skinfolds and body-composition scales cannot confirm loss on their own. Most patients have no past value, and illness and fluid shift them.
- In a group home or long-term care, weigh every resident on a schedule. Waiting until someone looks thin finds loss late.
| Measure | Shows real loss? | Why |
|---|---|---|
| Measured weight, gown, same checked scale | Yes | Same method each time, so a change is real |
| Self-reported weight | No | People guess, and a teen who restricts may hide it |
| Clothed bathroom-scale log | No | Clothes and an unchecked scale add error |
| Adult BMI cut-off in a teen | No | A growing teen needs her own growth curve |
| Albumin, skinfolds, body-composition scale | No | Rarely a past value; illness and fluid change them |
Key feature 3 of 3
Look again
When weight keeps falling and no cause is found yet, see the patient again soon and reassess.
CFPC skill Clinical reasoningPhase Follow-upSources Choosing Wisely Canada
On the exam
A woman of 78 with diabetes keeps losing weight after normal first tests. Expect a short menu (pick several from a list) of next steps.
Pick the follow-up plan and medicine changes.
Common mistakes
A recheck in a year because tests were normal, or a scan with no lead. Or keeping her sulfonylurea while she eats less and her A1c (average blood sugar) drops below 7.5%.
Approach
- Set a date for the next weight check before she leaves. Do not wait for the yearly visit.
- At each visit, weigh her on the same scale. Repeat the history and exam, and look for a new lead.
- Test what a new symptom or sign points to. Without a lead, more scans rarely help.
- Ask again about mood, memory, meals, money and loneliness. These can surface later.
- In many adults 65 and older, do not use drugs that can cause low blood sugar to bring the A1c (average blood sugar) below 7.5%. These include insulin and sulfonylureas (pills such as gliclazide).
- In frail long-term care residents, aim to avoid low blood sugar, not to hit a tight A1c. Recheck A1c no sooner than 3 months.
- A teen with ongoing loss and a slow pulse needs close checks of weight, pulse, and blood pressure lying and standing. Do not wait for the next routine visit.
Flashcards
Answer it first, then check.
KF 1An older woman says she has lost weight. What do you confirm first?
That the loss is real: measured weights on the same scale, and how much over how long.
KF 1Basic tests are pending and she has no bowel symptoms. Do you book a colonoscopy?
Not yet. Without bowel symptoms or anemia, scopes come after the basic tests, not before.
KF 1A teen has lost weight and her periods have stopped. What is the first test?
A pregnancy test. Pregnancy and weight loss explain missed periods far more often than a pituitary tumour.
KF 1You want to check a teen for celiac disease. Which tests do you send?
Tissue transglutaminase IgA, plus a total IgA level. Save other antibodies for IgA deficiency. Source: Choosing Wisely Canada
KF 2A 15-year-old has a BMI above the adult underweight cut-off. Is her weight fine?
Not on that alone. Plot her on a growth curve; adult BMI cut-offs do not apply to teens.
KF 2Why is a group home's clothed bathroom-scale log not enough?
Clothes and an unchecked scale make it wrong. Weigh her in a gown on a checked scale.
KF 3Her first tests are normal, but the loss goes on. When do you see her?
Soon, at a set date, with a measured weight. Normal tests do not end the search.
KF 3A woman of 79 on a sulfonylurea now has an A1c of 6.2%. What next?
Stop or cut the sulfonylurea. In many adults 65 and older, avoid drugs that cause low blood sugar to reach an A1c below 7.5%. Source: Choosing Wisely Canada
FAQ
Is there a Canadian guideline for weight loss with no clear cause?
No single one covers all ages. The exam marks the approach: confirm the loss with measured weights, search with history and exam, then see the patient again.
How do I say how much weight was lost?
As a percentage of the patient's own usual weight, over a stated time. That needs dated weights in the chart, taken the same way each time.
Should I order a CT scan to look for a hidden cancer?
Not as a first step. Let the history, exam and basic tests guide any scan. A scan with no lead often finds harmless things that need more tests.
When does a teen losing weight need hospital?
When she is medically unstable. Signs are a very slow pulse, low blood pressure, a big change on standing, a low temperature, or abnormal blood salts or heart tracing (ECG).
Sources
Written from the CFPC Assessment Objectives and Canadian guidelines first. Checked by a Canadian family physician, MD, CCFP.
Last reviewed October 20, 2026For exam study. Not advice for a patient in front of you.
- Assessment Objectives for Certification in Family Medicine, 2nd editionCollege of Family Physicians of Canada · 2020
- Choosing Wisely recommendationsChoosing Wisely Canada