Moderate carbohydrate restriction
Cut bread, pasta, rice and sweet drinks. Lowers triglycerides reliably; in lean people ApoB can rise.
Order of magnitude
100 to 130 grams of carbohydrate a day, keeping protein and unsaturated fat.
This lever is the clearest example of an offset in the whole database.
Effects in detail
Each row is a directed edge from our database, with range, latency, evidence grade and the condition under which it applies at all.
| Marker | Effect | Latency | Mode of action | Outcome | Evidence | Condition | Sources |
|---|---|---|---|---|---|---|---|
| HbA1c | helps. Lowers Direction known, size not established Twenty-three randomised trials in 1357 people with type 2 diabetes, including unpublished data, show substantially higher rates of remission defined as HbA1c below 6.5 % at 6 months on low and very low carbohydrate diets. No mean HbA1c change is entered because the outcome reported is remission, not a mean difference. | 26–26 weeks | chronic | unclear | Evidence grade A | applies regardless of the starting value | |
| Lipoprotein(a) | helps. Lowers -15.0 % one number, stated in a consensus table without an interval. The same passage also says 10 to 15 %, so treat 15 % as the favourable end rather than as the expected effect The same consensus table gives about a 15 % decrease in Lp(a) for a low-carbohydrate diet high in saturated fat, and the text says lifestyle interventions have minimal impact but that such a diet may lower Lp(a) by 10 to 15 %. Grade C for the same reason as the row above. | not specified | chronic | unclear | Evidence grade C | applies regardless of the starting value | |
| Triglycerides | helps. Lowers -11.5 mg/dL confidence interval of the estimate, not the range one person can expect Eight randomised trials with more than 100 participants each and at least six months' duration give a triglyceride difference of -0.13 mmol/L (95 % CI -0.19 to -0.08) in favour of carbohydrate restriction over a low-fat diet. The comparator is a low-fat diet, not usual eating, so part of the difference is the low-fat arm's triglycerides rising. | 26–26 weeks | chronic | unclear | Evidence grade A | applies regardless of the starting value |
What this measure costs
Counteracting effects of the same measure.
No counteracting effect is on file for this measure. That does not mean there is none, only that we found no defensible edge.
Moves without implying progress
Informational or no established effect: the marker moves or was checked, and that is not progress.
| Marker | Effect | Latency | Mode of action | Outcome | Evidence | Condition | Sources |
|---|---|---|---|---|---|---|---|
| Apolipoprotein B | moves, and does not count. Depends on the starting point Direction known, size not established the bounds are two subgroup estimates from a meta-regression: -7 mg/dL at a mean BMI of 35 and above, +41 mg/dL below 25. No single number describes this row, which is why direction is variable Across 41 randomised trials with 1379 participants, baseline BMI explained 51.4 % of the variance in the LDL-C response. direction: variable. Trial proxy: ldl_c. | not specified | chronic | unclear | Evidence grade A | applies regardless of the starting value | |
| Diastolic blood pressure | checked, nothing happens. No established effect Twenty-three randomised trials in 1664 participants found no significant effect of ketogenic diets on systolic (-0.87 mmHg, 95 % CI -2.05 to +0.31) or diastolic blood pressure (-0.11 mmHg). The trials tested a stricter restriction than this lever describes, so the null is an upper bound on what moderate carbohydrate restriction would do. | not specified | chronic | unclear | Evidence grade A | applies regardless of the starting value | |
| Systolic blood pressure | checked, nothing happens. No established effect Twenty-three randomised trials in 1664 participants found no significant effect of ketogenic diets on systolic (-0.87 mmHg, 95 % CI -2.05 to +0.31) or diastolic blood pressure (-0.11 mmHg). The trials tested a stricter restriction than this lever describes, so the null is an upper bound on what moderate carbohydrate restriction would do. | not specified | chronic | unclear | Evidence grade A | applies regardless of the starting value | |
| HDL cholesterol | moves, and does not count. Raises 3.10 mg/dL confidence interval of the estimate, not the range one person can expect HDL-C was 0.08 mmol/L higher (95 % CI 0.06 to 0.11) on carbohydrate-restricted than on low-fat diets across eight longer trials, which is +2.3 to +4.3 mg/dL. The range is the confidence interval of the 100 to 130 g/day comparison converted to mg/dL. | 26–26 weeks | chronic | no | Evidence grade A | applies regardless of the starting value | |
| high-sensitivity CRP | moves, and does not count. Lowers -0.14 mg/L confidence interval of the estimate, not the range one person can expect Sixty randomised trials in 5511 adults gave an average CRP reduction of 0.18 mg/L, but removing a single study reduced this to -0.14 mg/L (95 % CI -0.28 to 0.00, p = 0.052) and made it non-significant. Grade C because a result that disappears when one study is removed is not a body of evidence, whatever the number of trials. | not specified | chronic | unclear | Evidence grade C | applies regardless of the starting value |
Sources
Full details of every study the rows above rely on.
Effect of ketogenic diet on blood pressure: a GRADE-assessed systematic review and meta-analysis of randomized controlled trials
Amini et al. · Nutrition, Metabolism and Cardiovascular Diseases · 2024 · Meta-analysis
Effect of low glycaemic index or load dietary patterns on glycaemic control and cardiometabolic risk factors in diabetes: systematic review and meta-analysis of randomised controlled trials
Chiavaroli et al. · BMJ · 2021 · Meta-analysis
Effects of carbohydrate-restricted diets on low-density lipoprotein cholesterol levels in overweight and obese adults: a systematic review and meta-analysis
Gjuladin-Hellon et al. · Nutrition Reviews · 2019 · Meta-analysis
Efficacy and safety of low and very low carbohydrate diets for type 2 diabetes remission: systematic review and meta-analysis of published and unpublished randomized trial data
Goldenberg et al. · BMJ · 2021 · Meta-analysis
Effect of Low-Carbohydrate Diets on C-Reactive Protein Level in Adults: A Systematic Review and Meta-Analysis of Randomized Controlled Trials
Khodarahmi et al. · Food Science & Nutrition · 2025 · Meta-analysis
Lipoprotein(a) in atherosclerotic cardiovascular disease and aortic stenosis: a European Atherosclerosis Society consensus statement
Kronenberg et al. · European Heart Journal · 2022 · Guideline
Effects of high vs low glycemic index of dietary carbohydrate on cardiovascular disease risk factors and insulin sensitivity: the OmniCarb randomized clinical trial
Sacks et al. · JAMA · 2014 · Randomised trial
Increases in low-density lipoprotein cholesterol during carbohydrate-restricted diets are dependent on the amount of leanness
Soto-Mota et al. · American Journal of Clinical Nutrition · 2024 · Meta-analysis