How this instrument works
The Diet Risk Score (DRS) is a nine-item additive screening tool published by Emily Johnston and colleagues in BMJ Nutrition, Prevention & Health in 2020 (this project read the full open-access text directly on PMC). The paper built it specifically to estimate cardiometabolic disease risk — the dietary drivers of cardiovascular disease and diabetes identified in earlier risk-modeling research — not general diet quality, cancer risk, or overall mortality. Nine food groups are each rated by how often someone eats them, the nine ratings are added together, and the sum — a whole number from 0 to 27 — is the total DRS, a rough proxy for how closely someone's everyday eating resembles a lower-risk or higher-risk pattern for that specific outcome.
Five of the nine items — fast food, bread, salty snacks, sugar-sweetened drinks, and processed meat — score higher the more often they're eaten, but only four of them follow a smooth gradient: for fast food, bread, salty snacks, and sugar-sweetened drinks, Daily scores 3, 2-3 times a week scores 2, once a week scores 1, and Never scores 0. Processed meat is the one exception worth flagging clearly: in the published scoring table, any frequency above Never scores the full 3 points, so eating sausage or deli meat just once a week counts exactly the same as eating it daily. That is not a transcription error — it is how Johnston and colleagues built the table, apparently treating any regular processed-meat intake as an equally serious flag.
The remaining four items — nuts, fish, vegetables, and fruit — are reverse-scored, since eating them often is protective rather than risky. Nuts run 0, 0, 2, 3 across Daily, 2-3 times a week, once a week, and Never; fish runs 0, 0, 1, 3 the same way — fish reaches only 1 point at once a week, not 2, so nuts and fish diverge once you're past 2-3 times a week. Vegetables and fruit use a stricter pattern: 0 points only for Daily, and 3 points — the maximum — for anything less than daily, including 2-3 times a week. A single missed day of vegetables or fruit costs as much on this scale as never eating them at all.
The published paper sorts totals into three tiers: 0-8 is low risk, 9-18 is moderate, and 19-27 is high — categories the paper states directly rather than ones inferred here. Worth reading honestly: the tool was derived and validated on just 126 adults, 87% of them women, self-selected volunteers recruited through ResearchMatch and aged 35 to 75 — a small, non-representative sample whose average diet quality (HEI-2015 of 63.3) ran higher than the U.S. national average of roughly 59, meaning the high-risk tier (19-27) was the least-tested part of the scale, since few validation-sample participants scored that poorly. The original paper cautioned that generalizing the DRS to more diverse populations needed further testing, and later independent attempts have found weaker agreement outside the original sample: a 2023 study in Chinese American adults found r = -0.43 against HEI-2015 (versus -0.6 originally), and a 2024 Spanish-language feasibility study found r = -0.45. Within the original sample, the DRS correlated inversely with the Healthy Eating Index-2015 (r = -0.6, p < 0.001), and the group's own average score was 11.8 — solidly in the moderate tier.
- Rate how often you eat fast food, bread, salty snacks, and sugar-sweetened drinks — Daily, 2-3 times/week, 1 time/week, or Never.
- Rate processed meat (sausage, deli meat, hot dogs) the same way — any frequency above Never scores the maximum 3 points.
- Rate nuts and fish — these score in reverse, so eating them daily scores 0 and never eating them scores the most points.
- Rate vegetables and fruit — only eating them daily scores 0; anything less often scores the maximum 3 points.
- Read the total (0-27) and the risk tier — low, moderate, or high — the nine answers add up automatically.
Worked example — a moderate-risk total of 14
Take someone eating fast food about once a week (1 point), bread 2-3 times a week (2 points), salty snacks about once a week (1 point), any processed meat at all, even just once a week (3 points, since any frequency above Never scores the same as daily), sugar-sweetened drinks about once a week (1 point), nuts only about once a week (2 points, since infrequent nut-eating still costs 2 of the possible 3), fish about once a week (1 point), vegetables 2-3 times a week (3 points, since anything short of daily scores the maximum), and fruit every day (0 points, since daily is the only zero-scoring answer for fruit).
Adding the nine figures — 1 + 2 + 1 + 3 + 1 + 2 + 1 + 3 + 0 — gives a total of 14, which falls inside the moderate-risk tier (9-18) and sits close to the 11.8 mean DRS that Johnston and colleagues reported for their own 126-person validation sample, a useful anchor for what a typical moderate reading looks like in practice.
Questions
What is the Diet Risk Score (DRS)?
It's a nine-item, additive screen published by Johnston and colleagues in BMJ Nutrition, Prevention & Health in 2020, built to estimate cardiometabolic disease risk — the dietary drivers of cardiovascular disease and diabetes — rather than general diet quality, cancer risk, or overall health. Each of nine food groups is rated by how often it's eaten, the nine ratings are added together, and the sum — 0 to 27 — sorts into a low, moderate, or high risk tier. It was built for quick use in clinical practice, not as a replacement for a full dietary assessment.
Why does processed meat score 3 points for any consumption, not just daily eating?
That asymmetry is a real feature of the published scoring table, not an error. Fast food, bread, snacks, and sugary drinks scale gradually — 0, 1, 2, or 3 points depending on frequency — but processed meat scores 0 only for Never and the full 3 points for any frequency above that, including just once a week. Johnston and colleagues built the table that way, treating any regular processed-meat intake as an equally significant flag rather than a graded one.
Why are nuts, fish, vegetables, and fruit scored in reverse?
Because eating them often is protective, not risky, so the DRS rewards frequent consumption with a lower score. Nuts and fish both score 0 for Daily or 2-3 times a week, but they diverge from there: nuts rise to 2 points at once a week and the full 3 at Never, while fish rise to just 1 point at once a week and reach 3 only at Never. Vegetables and fruit use a stricter version of the same idea: they score 0 only for Daily, and anything less often, even 2-3 times a week, scores the maximum 3 points.
What do the DRS risk tiers mean?
Johnston and colleagues sort the 0-27 total into three published tiers: 0-8 is low risk, 9-18 is moderate, and 19-27 is high. For context, the study's own 126-person sample averaged a DRS of 11.8, solidly inside the moderate range, so a score in the low teens is closer to typical than alarming, while scores well into the 20s reflect a pattern the paper's own categories flag as high risk.
How reliable is the DRS, and who was it tested on?
The DRS was validated on a small, self-selected sample: 126 adults recruited through ResearchMatch, 87% women, aged 35 to 75. It correlated inversely with the Healthy Eating Index-2015 (r = -0.6, p < 0.001), but that headline number overstates classification accuracy: only 37% of participants landed in the same HEI-2015 quintile as their DRS quintile, 41% were within one quintile, and the weighted kappa was 0.28 — fair, not strong, agreement for sorting people into risk tiers. The sample's diet quality also ran higher than the U.S. average, so the high-risk tier was tested on very few people, and later studies found weaker correlations outside this sample.
Is the Diet Risk Score a diagnosis?
No. It's a screening and self-reflection tool, designed to flag eating patterns worth a closer look, not to diagnose a condition or replace a full dietary assessment. The intended use is prompting a conversation with a doctor or registered dietitian about what's actually being eaten, especially when a total lands in the moderate or high tier.
How does the DRS compare to other diet-quality measures like the Healthy Eating Index?
The two measure similar ground differently. The Healthy Eating Index-2015 (HEI-2015) is a detailed, multi-component index built from a full dietary recall, while the DRS is nine questions answered in under a minute. In the DRS validation study, the two moved in the expected opposite directions: a higher DRS tracked with a lower HEI-2015 score (r = -0.6, p < 0.001), one piece of evidence the short screen captures something real, even though it's far less detailed than a full index.
References
- Johnston et al., 2020, BMJ Nutrition Prevention & Health (PMC full text)
- Johnston et al., 2020, Diet Risk Score, DOI (BMJ Journals)
Read this first: This instrument computes a screening figure from population formulas — it is not a diagnosis, and it cannot see the whole picture a clinician can. Use it to inform a conversation, not to replace one.