“I’ve Been Losing Weight…”—Is It Really Diet Success?

When Body Weight Changes Signal Something Deeper

by poohmedical | June 9, 2025

“I feel like I’ve been gaining weight…”
“I’ve suddenly lost 3kg recently…”

Body weight change may look like a simple lifestyle issue—but it can be a red flag for serious illness. This article explores how family physicians can approach weight fluctuations, balancing psychological and physical causes through systematic evaluation.

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🩺 What You’ll Learn in This Article

• A structured approach to unexplained weight gain/loss (History–Exam–Tests)
• How to differentiate psychological from organic diseases
• The clinical value of weight as a screening tool for lifestyle-related diseases

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🧑‍⚕️ Case Introduction

“I’ve lost about 3kg recently…
I still have a normal appetite, but I’m worried it might be my eating disorder returning.”

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💡 First Impressions — How Would You Approach This?

Let’s be honest—many of us may immediately think:
“Ah, probably anorexia nervosa again…”
Especially when it’s a young woman with a past history of an eating disorder.

But stop right there.

Even if appetite is preserved, physical conditions like diabetes, thyroid disease, or malabsorption could be the real cause. More serious possibilities like malignancy, chronic kidney disease, TB, or HIV should not be overlooked.

🧭 Family doctors must look beyond assumptions and stay objective through physical exam and testing.

Likewise, when a patient says, “I think I’ve been gaining weight lately,” we must resist the urge to casually blame aging or overeating.

Conditions like hypothyroidism, Cushing’s syndrome, PCOS, and atypical depression—or even side effects of medications like antidepressants and steroids—could be at play.

✅ Weight change is a key symptom that offers opportunities for preventive care, especially in detecting lifestyle-related diseases.

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🧠 Clinical Reasoning with FPH (Fact–Problem–Hypothesis)

📉 Weight Loss

• Fact: “I lost 3kg without dieting.” / “My appetite is normal.” / “I’m sweating more.” / “I feel tired.”
• Problem: Unintentional / subacute / appetite preserved / active
• Hypothesis (VITAMIN CDE): Hyperthyroidism, diabetes, malignancy, chronic infections (TB/HIV), malabsorption

Red Flags: >5% weight loss in 6 months, night sweats, GI bleeding, anorexia + smoking history, elderly with rapid weight loss

📈 Weight Gain

• Fact: “I’ve gained 3kg.” / “I snack more.” / “Feeling tired, low mood.”
• Problem: Unintentional / subacute / appetite increased / low activity
• Hypothesis (VITAMIN CDE): Hypothyroidism, Cushing’s, PCOS, atypical depression, medication side effects

Red Flags: rapid gain, edema, menstrual issues, central obesity, binge eating + amenorrhea in young women

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🪜 Step-by-Step Clinical Approach

📝 Step 1: History Taking (OPQRST + PAM HITS FOSS)

• OPQRST: Onset, Progression, Quality, Related Symptoms, Severity, Timing, Trigger
• PAM HITS FOSS: PMH, Allergies, Medications, Hospitalizations, Immunizations, Travel, Sexual, Family, Obstetric/Gyne, Social

👀 Step 2: Physical Exam

• Vitals (HR, BP, Temp)
• Skin: pigment, dryness, hair loss
• Eyes: proptosis, tremor
• Neuropsychiatric: mood, cognition

🧪 Step 3: Labs & Imaging

• Labs: TSH, FT4, HbA1c, CBC, CRP
• Urine: glucose, ketone
• Imaging: CXR, abdominal US/CT, brain MRI

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🔄 Clinical Reflection: Back to the Case

Interview: weight loss, normal appetite, insomnia, sweating → ruled out relapse of ED → suspect hyperthyroidism

Exam: HR 96, fine tremor, no goiter → consistent with thyrotoxicosis

Labs: TSH low, FT4 elevated → Graves’ disease

Conclusion: Not a psychiatric issue—endocrine cause (Graves’ disease)

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🧠 Tips for History and Exam

• Ask: “How many kg in how long?”
• Clarify appetite
• Inspect skin, hands, eyes

💡 Clinical Pearls

“Weight loss without trying should always raise a red flag.”

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🗣️ Useful Medical Phrases

• “Have you noticed any recent changes in your weight?”
• “Was the weight loss intentional or unintentional?”
• “How is your appetite?”
• “Are you currently taking any medications?”

💬 Layman’s Terms & Idioms

📉 Weight Loss

• “I’m dropping weight without trying.”
• “My clothes feel loose.”
• Vocabulary: drop weight, shed pounds, shrink, loose clothes

📈 Weight Gain

• “I haven’t changed anything, but I’m gaining weight.”
• “I feel bloated.”
• Vocabulary: gain weight, put on pounds, feel heavy, bloated

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📖 Glossary

• Unintentional: not deliberate
• PCOS: Polycystic ovary syndrome
• SAS (OSA): Sleep apnea syndrome
• Bloating: sensation of fullness
• Cachexia: wasting from chronic illness
• Craving: strong urge to eat
• Swelling: edema
• Diuretics: meds that reduce fluid

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🧾 Final Thoughts

Weight isn’t just a number—it reflects emotions, lifestyle, hormones, and sometimes serious disease. Ask, listen, and connect the dots. What seems like “just weight” may be the key to saving someone’s life.

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🔗 Related Articles

• How to Approach Depression
• Understanding Abdominal Distention
• Back to Top Page: Symptom-based Approach
• Study in Japanese: Click here

📚 References

• UpToDate: Unintentional weight loss in adults
• Harrison’s Principles of Internal Medicine, 20th ed.
• Japan Thyroid Association Guidelines 2023
• DSM-5: Feeding and Eating Disorders
• Japan Diabetes Society Guidelines 2024