Informational 1,400 words 12 prompts ready Updated 04 Apr 2026

How to Use the COM-B Model to Diagnose Why Diets Fail

Informational article in the Behavior Change Tactics to Improve Diet Adherence topical map — Foundations: Behavior Change Frameworks and Models content group. 12 copy-paste AI prompts for ChatGPT, Claude & Gemini covering SEO outline, body writing, meta tags, internal links, and Twitter/X & LinkedIn posts.

← Back to Behavior Change Tactics to Improve Diet Adherence 12 Prompts • 4 Phases
Overview

How to Use the COM-B Model to Diagnose Why Diets Fail: apply the COM-B model (Michie, van Stralen & West, 2011) to map each episode of diet non‑adherence to one of the three domains—Capability, Opportunity, Motivation—and verify domain deficits with brief measures such as a 7‑day food record, an environmental audit, and a short capability checklist. The COM‑B framework defines Capability as psychological and physical skills, Opportunity as physical and social factors, and Motivation as reflective and automatic processes, making it possible to identify the single most limiting component and prioritize targeted behavior change techniques. This yields a clear, single priority domain for intervention.

The model works because it connects diagnostic assessment to intervention selection through the Behavior Change Wheel and the Behavior Change Technique Taxonomy (BCTTv1). By using tools such as the Theoretical Domains Framework (TDF) questionnaire, brief self‑monitoring (food logs or digital apps) and Motivational Interviewing to probe reflective motivation, clinicians can translate a COM‑B deficit into specific behavior change techniques—goal setting, action planning, stimulus control—that improve diet adherence. This mapping clarifies why diets fail in practice: a recommendation like “eat more protein” is ineffective if lack of cooking skills (Capability) or limited grocery access (Opportunity) is the root cause. The paragraph supports behavior change for weight loss with a diagnostic checklist for dieting including clinician-led digital tools for remote dietary monitoring.

A common misconception is treating COM‑B as abstract theory rather than a clinic-ready diagnostic tool; this leads to generic prescriptions that ignore why diets fail in particular cases. For example, late-night snacking can reflect an Opportunity issue (shift work and visible cues), an automatic Motivation habit (cue‑triggered eating) or a Capability gap (few quick nutritious options), and each demands different BCTs. Evidence-based measures such as the Weight Efficacy Lifestyle (WEL) questionnaire for self‑efficacy, short environmental audits, and three-day or ecological momentary assessment food logs provide convergent data to confirm the limiting domain. Mapping these findings to intervention functions reduces relapse risk by targeting diet relapse reasons with tailored tactics rather than one-size-fits-all advice. Especially useful in COM-B in nutrition counseling settings.

Practically, clinicians should run a brief diagnostic battery—short capability checklist, WEL or similar motivation scale, a 3–7-day food record and an environmental audit—then map identified deficits to intervention functions (education, enablement, environmental restructuring) and specific behavior change techniques from the BCTTv1. Progress should be tracked with the same brief measures at 2–4-week intervals to confirm mechanism change and regularly measure change in adherence metrics. The structured, step-by-step diagnostic framework in this page links COM‑B assessment to prioritized, measurable interventions for improved diet adherence. This approach supports measurable behavior change for weight loss and long-term maintenance.

How to use this prompt kit:
  1. Work through prompts in order — each builds on the last.
  2. Click any prompt card to expand it, then click Copy Prompt.
  3. Paste into Claude, ChatGPT, or any AI chat. No editing needed.
  4. For prompts marked "paste prior output", paste the AI response from the previous step first.
Article Brief

COM-B model diet

How to Use the COM-B Model to Diagnose Why Diets Fail

authoritative, evidence-based, practical

Foundations: Behavior Change Frameworks and Models

Registered dietitians, health coaches, clinicians, behavior-change practitioners, and motivated consumers with intermediate knowledge seeking actionable diagnostics to improve diet adherence

A practical diagnostic playbook that maps each COM-B component to diet-specific causes, evidence-based tactics, ready-to-use tools and templates, and special-population adaptations — not just theory but clinic-ready steps and measurement guidance.

  • COM-B model
  • diet adherence
  • why diets fail
  • behavior change for weight loss
  • capability opportunity motivation
  • behavior change techniques for diets
  • diet relapse reasons
  • diagnostic checklist for dieting
  • COM-B in nutrition counseling
  • barriers to diet adherence
Planning Phase
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1. Article Outline

Full structural blueprint with H2/H3 headings and per-section notes

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You are creating a ready-to-write, publish-ready outline for the article titled 'How to Use the COM-B Model to Diagnose Why Diets Fail'. This article is informational, targets clinicians and informed consumers, and must be tightly practical and evidence-focused. Produce a complete structural blueprint including: H1, all H2s and H3s, suggested word counts per section that sum to ~1400 words, and a 1-2 sentence note under each heading describing exactly what content must cover (including examples, diagnostics, and tools). Ensure the outline maps COM-B components to diet-specific failure modes, includes an evidence & tools section, special populations, measurement plan, and ethical considerations. Be explicit about where to place templates (checklist or table), callouts for case studies, and where to insert E-E-A-T signals. Include transition sentences between major sections to preserve flow. End by listing at least three suggested micro-CTAs (email sign-up, diagnostic PDF, link to pillar article). Output format: Provide the outline as a numbered list with headings clearly labeled (H1, H2, H3) and word targets in brackets next to each heading.
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2. Research Brief

Key entities, stats, studies, and angles to weave in

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You are producing a research brief for 'How to Use the COM-B Model to Diagnose Why Diets Fail'. List 8-12 specific entities: peer-reviewed studies, large-scale statistics, named behavior-change tools, expert names, validated scales, and trending angles the writer MUST weave into the article. For each item include a one-line note explaining why it belongs and how to cite or use it in the article (evidence, tool, counterargument, or example). Prioritize sources connecting COM-B to dietary adherence, habit relapse, motivation, and opportunity. Include at least: the original COM-B/BCW citation (Michie 2011), 1-2 randomized trials on diet adherence interventions, a meta-analysis on diet dropout rates, validated measurement tools (e.g., COM-B Self-Evaluation, SRHI habit index), a behavior-change taxonomy (BCTTv1), and a reputable statistic on diet failure rates. Also include one ethical guidance source for behavior interventions. Output format: present as a bulleted list where each bullet is the entity name followed by the one-line rationale and a suggested in-text citation (author, year).
Writing Phase
3

3. Introduction Section

Hook + context-setting opening (300-500 words) that scores low bounce

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Write the full introduction (300-500 words) for the article 'How to Use the COM-B Model to Diagnose Why Diets Fail'. Start with a sharp hook that highlights the common pain: high initial weight-loss followed by relapse. Provide immediate context: explain briefly what COM-B stands for (Capability, Opportunity, Motivation -> Behavior) and why a diagnostic approach outperforms generic advice. State a clear thesis: readers will learn a step-by-step diagnostic method to identify why a specific diet is failing and practical tactics to fix it. Preview the article structure and list 3 concrete outcomes the reader will be able to do after reading (e.g., complete a COM-B diet diagnostic, pick 3 targeted tactics, use two measurement tools). Use an authoritative but conversational tone, cite one high-level stat or study in-line (e.g., diet dropout rate), and include one short empathic sentence to build trust. End with a transition sentence leading to the first main section (Capability). Output format: return the introduction as plain text with a short suggested in-article headline and a 1-line meta hook for social sharing.
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4. Body Sections (Full Draft)

All H2 body sections written in full — paste the outline from Step 1 first

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You will write the full body of 'How to Use the COM-B Model to Diagnose Why Diets Fail', targeting the 1400-word article length. Paste the outline you received from Step 1 before running this prompt. Then, for each H2 in the outline, write that H2 section completely before moving to the next. Each H2 should include H3 subheadings, concrete diagnostic questions, short example case vignettes (1-2 sentences), evidence-backed tactics, and a short measurable action the reader can take (e.g., a one-week test or a tracking metric). Include transitions at the end of each H2 to the next. Content must map: Capability (physical and psychological), Opportunity (social and physical), Motivation (reflective and automatic), then a combined diagnostic checklist, tactics matrix (linking COM-B deficits to prioritized BCTs), measurement plan (tools and metrics), special-population adaptations (diabetes, older adults, low-income), and ethical considerations. Use an actionable, clinician-friendly voice; include at least one inline citation per major section. Output format: produce the article body as plain text in the same heading hierarchy (H2/H3) and keep the full draft within ~900-1000 words for the body (the intro and conclusion complete the 1400 target).
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5. Authority & E-E-A-T Signals

Expert quotes, study citations, and first-person experience signals

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Create an E-E-A-T injection pack for the article 'How to Use the COM-B Model to Diagnose Why Diets Fail'. Provide: (A) five suggested short expert quotes (1-2 sentences each) with suggested speaker name and credentials (e.g., Dr. Susan Michie, PhD, behavior scientist; Registered Dietitian; behavioral economist) and exactly where to place each quote in the article; (B) three real studies/reports (full citation lines) the writer must cite, with a 1-sentence note on which claim each study supports; (C) four experience-based first-person sentence templates the author can personalize (e.g., 'In my practice I see X, so I use Y...'). Also include a short list of two reputable organizations or journals to flag for review links (e.g., NICE, American Journal of Clinical Nutrition). Output format: return as three labeled sections: Expert Quotes, Studies to Cite, Personalization Templates.
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6. FAQ Section

10 Q&A pairs targeting PAA, voice search, and featured snippets

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Write 10 concise Q&A pairs for the FAQ block of 'How to Use the COM-B Model to Diagnose Why Diets Fail'. Questions should target People Also Ask, voice-search phrasing, and featured-snippet style. Each answer must be 2-4 sentences, conversational, specific, and actionable. Cover high-value queries such as 'What is COM-B?', 'How can COM-B explain diet failure?', 'Can COM-B predict relapse?', 'Which COM-B tools measure motivation?', 'Is COM-B better than stages-of-change?', and practical ones like 'How long does a diagnostic take?' and 'Can I use COM-B for intermittent fasting?'. Include short internal link suggestions in parentheses after 3 of the answers where relevant (anchor text only). Output format: provide a numbered list of Q&A pairs with question and answer clearly labeled.
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7. Conclusion & CTA

Punchy summary + clear next-step CTA + pillar article link

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Write the conclusion (200-300 words) for 'How to Use the COM-B Model to Diagnose Why Diets Fail'. Recap the key takeaways in 3-5 bullets (one sentence each), then provide a strong, specific CTA telling the reader exactly what to do next (download the COM-B diet diagnostic PDF, run a one-week test, book a coaching audit). Add a one-sentence segue pointing readers to the pillar article 'Behavior Change Frameworks for Diet Adherence: COM-B, TTM, Self-Determination and Habit Models Explained' for broader context. Use motivating, professional language and include one sentence about expected timeline to see change when applying these diagnostics. Output format: return the conclusion with bullets and the CTA clearly separated.
Publishing Phase
8

8. Meta Tags & Schema

Title tag, meta desc, OG tags, Article + FAQPage JSON-LD

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Generate SEO metadata and JSON-LD for 'How to Use the COM-B Model to Diagnose Why Diets Fail'. Provide: (a) title tag (55-60 characters) optimized for the primary keyword; (b) meta description (148-155 characters); (c) OG title (under 70 chars); (d) OG description (under 160 chars); (e) a complete Article + FAQPage JSON-LD block containing the article headline, description, author (use a generic author object with name and credentials), publishDate placeholder, mainEntityOfPage URL placeholder, and the 10 FAQs from the FAQ step. Use structured JSON-LD code block syntax and ensure the FAQ entries are inserted in the schema. Output format: return the metadata and the full JSON-LD schema as plain code that can be copied into the page head.
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10. Image Strategy

6 images with alt text, type, and placement notes

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Create an image strategy for 'How to Use the COM-B Model to Diagnose Why Diets Fail'. Recommend 6 images including: what each image should show, exact location in the article (e.g., after H2 'Capability'), the SEO-optimized alt text (must include primary keyword or a close variant), the preferred type (photo, infographic, screenshot, diagram), and a short note on dimensions/aspect ratio and whether to include copy overlay. Include one infographic idea that visualizes the COM-B diagnostic flow and one downloadable PDF thumbnail for the diagnostic checklist. Also suggest source types (stock photo, original graphic, clinical photo) and accessibility tips. Output format: return a numbered list with the six image entries, each with fields: description, placement, alt text, type, and production notes.
Distribution Phase
11

11. Social Media Posts

X/Twitter thread + LinkedIn post + Pinterest description

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Write three platform-native social posts promoting 'How to Use the COM-B Model to Diagnose Why Diets Fail'. (A) X/Twitter: a thread opener tweet (max 280 chars) plus 3 follow-up tweets that unpack the thread — write them as separate tweets. Use short, punchy lines and include one data point and one CTA to read the article. (B) LinkedIn: a 150-200 word professional post with a clear hook, one surprising insight, and a CTA to read the article or download the diagnostic PDF; keep tone expert and conversational. (C) Pinterest: an 80-100 word keyword-rich pin description for a pin showing the COM-B diagnostic infographic; include target keywords, a short benefit statement, and a call to click. Output format: present each platform section labeled and ready to copy-paste.
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12. Final SEO Review

Paste your draft — AI audits E-E-A-T, keywords, structure, and gaps

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You will perform a final SEO audit on the draft of 'How to Use the COM-B Model to Diagnose Why Diets Fail'. Paste the full article draft after this prompt before running. The AI should check and report: keyword placement and density for the primary keyword and 5 secondary keywords; heading hierarchy and H2/H3 optimization; E-E-A-T gaps and where to add expert quotes or citations; readability estimate and suggested grade level; duplicate-angle risk vs top 10 Google results (mention unique angle opportunities); content freshness signals (data, dates, study recency); and backlink-worthy elements to add (original checklist, dataset, template). Provide five prioritized, specific improvement suggestions (with exact sentence rewrites or paragraph insertions where needed). Output format: return a numbered audit with clear action items and copyable sentence/paragraph rewrites.
✗ Common Mistakes
  • Treating COM-B as abstract theory instead of a practical diagnostic tool — failing to link each component to specific diet behaviors
  • Giving generic diet tips rather than prioritized, COM-B-mapped tactics (e.g., advising 'eat more protein' without diagnosing capability or opportunity issues)
  • Neglecting measurement: not telling clinicians which short tools or metrics to use to confirm a deficit and track progress
  • Overlooking social and environmental opportunity barriers (food access, family dynamics, food marketing) and blaming patient motivation
  • Using one-size-fits-all advice instead of special-population adaptations (e.g., ignoring cultural food practices, diabetes medication interactions, or low-income constraints)
  • Failing to cite primary research or authoritative guidance (Michie 2011, BCT taxonomy), which weakens E-E-A-T for clinicians
  • Skipping ethics and consent when recommending behavior-change nudges — which can alienate readers concerned about autonomy
✓ Pro Tips
  • Include a two-page downloadable COM-B diet diagnostic checklist (PDF) that clinicians can complete in 5–10 minutes; make it linkable content that earns backlinks from practitioner forums
  • Map each diagnosed COM-B deficit to 3 prioritized Behavior Change Techniques (BCTs) from the BCTTv1 and show rapid A/B test ideas to validate which tactic reduces relapse fastest
  • Use short validated measurement instruments (e.g., single-item motivation scales, SRHI for habit strength, a simple food-environment audit) and show how to operationalize them in an app or intake form
  • Add one clinical micro-case study per section showing a 4-week micro-trial and the metrics used; small n success stories increase credibility and shareability
  • Provide specific language templates for clinicians' motivational interviewing scripts tied to COM-B findings (e.g., when motivation is low, use reflective affirmation + small commitment)
  • Recommend combining COM-B diagnosis with low-burden environmental tweaks (kitchen re-organization, grocery-list nudges) and list exact products/tools (e.g., meal-prep containers, digital habit trackers) to reduce friction
  • Highlight equity: include low-cost and no-cost tactics for low-income users (e.g., community food programs, shelf-stable meal hacks) and cite local data when possible
  • Create an SEO-optimized lead magnet headline (e.g., '5-Minute COM-B Diet Diagnostic: Printable Checklist') and gate it behind an email to grow an engaged practitioner list