Definition and Pathophysiology
Dietary patterns are the overall combinations of foods habitually consumed rather than isolated nutrients considered independently. For cardiometabolic health, the most favourable patterns generally contain more minimally processed, fibre-rich and bioactive foods, including fruits, non-starchy vegetables, beans, whole grains, nuts and seeds, yogurt, seafood and plant oils. They contain less refined grain, starch, added sugar, salt, trans fat, processed meat and, usually, red meat.
The principal evidence-supported patterns are Mediterranean-type and DASH-style diets. Their effects are multidimensional and cannot be adequately inferred from changes in a single intermediate marker such as cholesterol. Dietary composition may influence blood pressure, glucose–insulin homeostasis, lipids and apolipoproteins, endothelial function, systemic inflammation, liver fat synthesis, adiposity, thrombosis and coagulation, cardiac function, satiety, appetite, the gut microbiome and metabolic expenditure. Food processing, additives and cooking methods may also contribute.
The cardioprotective effect is therefore likely to result from the cumulative influence of multiple modest dietary changes. Mediterranean-type diets provide polyphenols from extra-virgin olive oil, fruits, vegetables, nuts and legumes; unsaturated fatty acids and other bioactive compounds from nuts; and antioxidant and antithrombotic constituents from whole grains. These combined effects may improve inflammation, insulin resistance, glucose metabolism, hypertension, atherogenic dyslipidaemia, endothelial biology and platelet-related pathways. The source material also describes possible antiarrhythmic effects, associated with reductions in sudden cardiac death and atrial fibrillation.
Dietary quality also affects energy balance. Highly processed foods may promote greater ad libitum intake through effects on hunger, reward, craving, glucose–insulin responses, gut peptides, hepatic fat synthesis, adipocyte function and metabolic expenditure. Consequently, obesity is only one pathway through which diet affects cardiovascular health; dietary changes can improve cardiometabolic risk factors within 6–8 weeks even without weight loss.
Cardiovascular Outcomes Associated With Dietary Patterns
Cardiovascular disease and mortality
The strongest long-term evidence supports Mediterranean or DASH-style patterns that emphasize minimally processed foods and healthy fats while limiting ultraprocessed foods, refined carbohydrates, sugars and meats.
In secondary prevention, randomized trials in people with established coronary disease found fewer cardiovascular events with Mediterranean dietary interventions than with low-fat control diets. In one trial of patients with previous myocardial infarction, the Mediterranean intervention involved greater consumption of fruits, vegetables, legumes, bread and an alpha-linolenic-acid-rich margarine, with lower consumption of meat, processed meat, butter and cream. Primary cardiovascular events occurred in 8 of 302 participants in the Mediterranean group compared with 33 of 303 in the control group. In another randomized trial involving 1002 patients with established coronary disease, a Mediterranean diet was associated with more than a one-quarter reduction in major cardiovascular events over 7 years compared with a low-fat diet.
In primary prevention, a large randomized trial involving 7447 individuals at high cardiovascular risk reported a 30% reduction in major cardiovascular events with a Mediterranean diet supplemented with either nuts or extra-virgin olive oil compared with a low-fat dietary pattern. The intervention included broader dietary modification, particularly increased fruit, legume and seafood intake and reduced meat, meat products and sweets.
An umbrella review incorporating observational studies and randomized trials reported associations between greater adherence to a Mediterranean diet and lower risks of cardiovascular disease, myocardial infarction, stroke, cardiovascular mortality and diabetes. A network meta-analysis of randomized trials found that, compared with minimal dietary intervention, Mediterranean dietary intervention was associated with a 28% lower risk of all-cause death and a 45% lower risk of cardiovascular death.
Heart failure
A plant-forward diet emphasizing vegetables, fruit, beans and fish was associated with a 41% lower risk of incident heart failure in a cohort of more than 16,000 participants followed for a median of 8.7 years. Conversely, the highest consumption of processed meats, eggs, added fat and sugar-sweetened beverages was associated with a 72% higher risk of incident heart failure than the lowest consumption. These associations were strongest in patients with heart failure and reduced ejection fraction.
The favourable effects of plant-forward eating have not been definitively attributed to one component, but may relate to the abundance of phytochemicals with antioxidant and anti-inflammatory properties.
Diabetes and cardiometabolic risk
Mediterranean-style eating improves glycaemic control, lipid levels and blood pressure in people with type 2 diabetes. In a high cardiovascular-risk population in which approximately half the participants had type 2 diabetes, a Mediterranean diet supplemented with olive oil or nuts was associated with a 28–31% reduction in atherosclerotic cardiovascular disease risk.
Mediterranean, paleo, vegetarian and low-carbohydrate diets have each reduced fasting glucose or HbA1c in trials, although few studies extended beyond 1 year. A shift from a predominantly animal-based to a plant-based food pattern may also lower atherosclerotic cardiovascular disease risk.
Dietary changes may improve multiple risk factors independently of weight reduction. Mediterranean-type patterns have been associated with improvements in inflammation, insulin resistance, glucose metabolism, hypertension and atherogenic dyslipidaemia.
Clinical Presentation and Symptoms
Dietary patterns do not produce a distinctive clinical syndrome. Their cardiovascular effects generally emerge through established conditions and risk factors, including obesity, hypertension, dyslipidaemia, type 2 diabetes, coronary disease, stroke, heart failure and related cardiometabolic disorders.
The source material does not describe a specific symptom profile or physical presentation attributable to dietary patterns alone. Clinical assessment should therefore focus on the cardiovascular diseases and risk factors present, together with a structured assessment of habitual food intake, food processing, energy balance, weight trajectory and dietary adherence.
Evaluation and Physical Examination
Evaluation should establish the patient’s current dietary pattern and its relationship to cardiovascular risk. Important domains include:
Consumption of fruits, vegetables, beans, whole grains, nuts, seeds, yogurt, seafood and plant oils.
Intake of refined grains, starches, sugar-sweetened beverages, sweets, bakery foods, processed meats, red meat, salt and trans fat.
Portion sizes, meals eaten away from home and consumption of ultraprocessed foods.
Weight trajectory, abdominal adiposity and energy balance.
Physical activity, sedentary behaviour, sleep duration and television viewing.
Food availability, cultural preferences, financial constraints and food security.
Previous dietary interventions, adherence and barriers to sustained change.
Presence of obesity, hypertension, dyslipidaemia, diabetes, coronary disease, heart failure or other cardiovascular comorbidity.
Physical examination findings are not specific to diet. Assessment should include the clinical consequences of dietary risk, including body weight, adiposity and findings relevant to hypertension, diabetes, dyslipidaemia, coronary disease and heart failure. The source material does not provide a dedicated examination protocol for dietary counselling.
Diagnostics and Laboratory Findings
No specific ECG, imaging or electrophysiological test diagnoses an unhealthy dietary pattern. Diagnostic investigations should be directed toward the cardiovascular conditions and risk factors being assessed.
Relevant laboratory monitoring may include markers of the metabolic pathways identified in the source material, particularly:
Blood lipids and apolipoproteins.
Glucose and HbA1c.
Triglycerides.
Blood pressure, although this is a clinical measurement rather than a laboratory test.
Other investigations required to evaluate established cardiovascular disease or its complications.
The source material indicates that dietary quality can improve cardiometabolic risk factors within 6–8 weeks, even without weight loss. It does not define a laboratory monitoring schedule or specify target values for individual biomarkers.
Dietary Composition for Cardiovascular Health
Foods to increase
The following food-based components are recommended within an overall healthful pattern. The serving targets are based on a 2000 kcal/day diet and should be adjusted according to energy requirements.
| Food group | Suggested intake | Approximate serving |
|---|---|---|
| Fruits | 3 servings/day | About 100 g; for example, one medium fruit, ½ cup fresh/frozen/canned fruit, ¼ cup dried fruit or ½ cup 100% juice |
| Vegetables and beans | 3–4 servings/day | About 100 g; for example, 1 cup raw leafy vegetables or ½ cup cut-up or cooked vegetables |
| Whole grains | 3 servings/day, replacing refined grains | About 50 g; for example, one slice whole-grain bread or ½ cup cooked whole-grain rice, pasta or cereal |
| Nuts | 4–5 servings/week | About 28 g |
| Fish and shellfish | 2 servings/week, preferably oily fish | About 100 g; avoid meeting this target with deep-fried or breaded fish |
| Dairy products, particularly yogurt | 2–3 servings/day | One cup of milk or yogurt, or 1.5 oz of cheese |
| Plant oils | 2–6 servings/day | About 1 teaspoon of oil or 1 tablespoon of vegetable spread |
A practical method for choosing healthier carbohydrate-rich products is to select foods providing at least 1 g of dietary fibre per 10 g of total carbohydrate per serving, corresponding to a carbohydrate-to-fibre ratio below 10:1.
Foods to limit or avoid
| Food or dietary factor | Suggested approach |
|---|---|
| Refined grains and starches | Minimize |
| Sugar-sweetened beverages, sweets and bakery foods | Avoid or consume only modestly, such as up to 5 servings/week |
| Processed meats | Minimize, for example up to 1 serving/week |
| Unprocessed red meat | Minimize, for example 1–2 servings/week |
| Industrial trans fat from partially hydrogenated oils | Avoid |
| Alcohol | Up to 1 drink/day in the dietary pattern table; in type 2 diabetes, intake should generally be moderate |
| Sugar-sweetened soft drinks and fruit juices | Avoid |
| Salt | Reduce intake; one guideline cited recommends less than 2300 mg/day |
Cardioprotective eating is best defined by the presence of healthful foods rather than simply by excluding all animal-source foods. Yogurt and fish are identified as beneficial, while poultry, eggs, milk and cheese are not considered to have meaningful harms in the cited dietary framework. Plant-based, vegetarian and vegan patterns can be cardioprotective when appropriately constructed, but may still contain refined grains, starches, added sugars, sugar-sweetened beverages and trans fats.
Treatment and Management
Foundational dietary strategy
Nutritional intervention is a foundation of cardiovascular disease prevention and treatment. The preferred approach is a food-based Mediterranean or DASH-style pattern adapted to local food availability, cultural traditions, preferences and medical conditions.
Management should address both inadequate intake of protective foods and excessive intake of harmful foods. The intervention should generally emphasize:
Greater consumption of fruits, vegetables, beans, whole grains, nuts, seeds, fish, yogurt and plant oils.
Replacement of refined grains with whole grains.
Reduction of processed and red meat.
Avoidance of sugar-sweetened beverages, fruit juice, industrial trans fat and excess added sugar.
Reduction of salt.
Limitation of ultraprocessed foods, fast food and prepared meals.
Portion control and appropriate energy intake.
Regular physical activity and reduction of sedentary behaviour.
Adequate sleep, reported in the dietary guidance as 7–8 hours.
Individualized behavioural counselling with specific, measurable, agreed, realistic and time-limited goals.
The food pattern should be sustainable rather than extreme. Multiple modest changes may be more feasible and more effective for adherence than major restriction of a few nutrients.
Weight reduction and obesity
For obesity management, energy restriction remains the cornerstone. A calorie deficit of 500–750 kcal/day compared with habitual intake may be used. Alternatively, the cited guidance describes diets providing 1200–1500 kcal/day for women and 1500–1800 kcal/day for men, adjusted for body weight. Lifestyle management typically produces modest weight loss, often approximately 3–5 kg compared with usual care.
Weight loss is influenced primarily by total energy reduction and adherence rather than by a single prescribed macronutrient ratio. Low-energy-density foods, including soups, fruits, vegetables and oatmeal, may improve hunger control by increasing food volume relative to calories. Meal replacements may be useful for portion control and have been associated with 7–8% weight loss in the cited material.
Very-low-calorie diets may be considered in selected, highly motivated individuals with moderate to severe obesity who have not responded to conservative treatment and have a medical condition likely to improve rapidly with weight loss. The cited formula diets provide no more than 800 kcal/day, 50–80 g of protein and 100% of the recommended daily intake for vitamins and minerals. They may produce 13–23 kg of short-term weight loss over 3–6 months. Such diets require trained practitioners, medical monitoring and high-intensity lifestyle support.
Diet, physical activity and behavioural therapy are foundational at the pre-obesity and obesity stages. Pharmacotherapy or bariatric surgery may be considered when lifestyle intervention is insufficient, according to body mass index, comorbidities and treatment response.
Macronutrient patterns
Low-carbohydrate, low-fat, high-protein, Mediterranean, vegetarian and intermittent-fasting approaches can produce broadly similar short-term weight loss when energy intake is reduced. By 12 months, the effects of many approaches tend to diminish, whereas benefits of the Mediterranean diet may persist.
Low-carbohydrate diets are described as:
Low carbohydrate: 50–130 g/day.
Very low carbohydrate: 20–49 g/day.
Moderate carbohydrate: more than 130–225 g/day.
Low or very low carbohydrate diets may help appetite control, lower triglycerides and reduce medication requirements in type 2 diabetes. Ketogenic diets may require medical or dietetic supervision. Long-term studies beyond 2 years are scarce, and extreme carbohydrate restriction should be avoided over the long term. Plant-derived substitutions for carbohydrate calories are considered preferable to animal-derived substitutions.
Intermittent fasting and time-restricted eating produce weight loss equivalent to continuous energy restriction when total energy intake is matched. The evidence does not establish one fasting method as superior to another, particularly in people with psychiatric conditions.
Heart failure
A plant-forward pattern emphasizing vegetables, fruit, beans and fish is associated with lower incident heart failure risk. In patients with heart failure and type 2 diabetes, the cited material reports that a high-protein diet containing 30% protein, 40% carbohydrate and 30% fat and a standard-protein diet containing 15% protein, 55% carbohydrate and 30% fat produced similar reductions in body weight and waist circumference. The high-protein diet produced greater reductions in HbA1c, cholesterol, triglycerides and blood pressure.
The source material does not provide a comprehensive heart-failure-specific dietary prescription beyond these observations.
Type 2 diabetes with or without cardiovascular disease
Patients with type 2 diabetes should follow a nutritional pattern that supports weight reduction, glycaemic control and cardiovascular risk reduction. Mediterranean-style eating improves glucose control, lipids and blood pressure. Sugar-sweetened beverages, sugars and fruit juices should be avoided. Sodium reduction is encouraged in people with cardiovascular disease and type 2 diabetes.
Reducing salt intake by 2.5 g/day was associated in the cited meta-analysis with a 20% relative reduction in atherosclerotic cardiovascular disease events. Salt substitution with lower sodium and higher potassium content reduced stroke, cardiovascular disease and overall mortality in people at high cardiovascular risk.
Routine n-3 fatty-acid supplementation is not supported for secondary cardiovascular prevention in type 2 diabetes by the cited evidence.
Mental health and cardiovascular disease
Dietary interventions may have simultaneous cardiovascular and mental-health benefits, but evidence for mental-health improvement in people with cardiovascular disease remains limited. Mediterranean diets have been associated with lower rates of depression and cognitive decline in the general population, but cardiovascular-disease-specific evidence remains emergent. Fasting and calorie restriction have yielded preliminary findings for mood and cognition, without sufficient evidence to endorse one method.
In a small heart-failure trial, eicosapentaenoic acid and docosahexaenoic acid supplementation was associated with favourable changes in cognitive depressive symptoms and social functioning; the small sample and soft endpoints require cautious interpretation. No definitive dietary recommendation for mental-health outcomes in cardiovascular disease can be made from the available evidence.
Drugs and Supplements
Dietary-pattern management is not principally pharmacological. The source material does, however, identify medications approved in Europe that may supplement lifestyle treatment for weight loss:
Orlistat.
Naltrexone/bupropion.
High-dose liraglutide.
These agents may assist weight reduction and maintenance but may cause adverse effects. No doses are provided in the source material.
The cited evidence does not support recommending n-3 fatty-acid supplements for secondary cardiovascular prevention in people with type 2 diabetes. Supplement use is widespread, but the source material provides no general supplement regimen or dosing recommendations.
Psychiatric drugs require particular caution in cardiovascular disease. Many psychiatric medications are associated with increased risk of sudden cardiac death, and antidepressants in heart failure have been associated with increased cardiac and all-cause mortality. Their use therefore requires interdisciplinary cooperation in patients with complex mental disorders or heart failure.
Guideline Recommendations
The available recommendations can be summarized as follows:
Use Mediterranean or DASH-style dietary patterns as the principal evidence-based approaches for long-term cardiometabolic health.
Emphasize minimally processed foods, fruits, vegetables, beans, whole grains, nuts, fish, yogurt and plant oils.
Reduce ultraprocessed foods, refined grains and starches, added sugars, sugar-sweetened beverages, salt, processed meat, red meat and industrial trans fat.
Adapt the dietary pattern to cultural traditions, food availability, preferences, energy requirements and comorbid disease.
For obesity, initiate structured lifestyle treatment with calorie reduction, physical activity and behavioural modification.
When lifestyle measures do not produce adequate results, consider escalation to weight-loss pharmacotherapy and, where appropriate, bariatric surgery.
In type 2 diabetes, use Mediterranean-style eating to improve glycaemic control, lipid levels, blood pressure and cardiovascular risk.
Encourage sodium reduction in people with cardiovascular disease and type 2 diabetes.
Avoid routine n-3 supplementation for secondary cardiovascular prevention in type 2 diabetes based on the cited evidence.
Use ketogenic or very-low-carbohydrate diets only with appropriate medical or dietetic supervision, and avoid extreme carbohydrate restriction as a long-term strategy.
Recognize that evidence for dietary treatment of mental-health outcomes in cardiovascular disease is currently insufficient for a specific recommendation.
Prognosis and Follow-up
Greater adherence to Mediterranean dietary patterns is associated with lower risks of cardiovascular events, myocardial infarction, stroke, cardiovascular mortality and diabetes. In randomized trials, benefits have been observed in both primary and secondary prevention, including reductions in major cardiovascular events and cardiovascular death.
The durability of benefit depends on sustained adherence. Many weight-loss diets show diminishing effects by 12 months, whereas Mediterranean dietary benefits appear more persistent. Long-term maintenance is supported by flexible, culturally relevant counselling and by focusing on overall dietary quality rather than extreme restriction of a single nutrient.
Follow-up should assess:
Dietary adherence and the specific foods being consumed.
Weight and waist trajectory.
Blood pressure.
Lipids and triglycerides.
Glucose and HbA1c when diabetes or dysglycaemia is present.
Cardiovascular symptoms and clinical status.
Physical activity, sedentary behaviour and sleep.
Practical barriers, food security and the feasibility of the dietary plan.
Adverse effects and effectiveness when weight-loss medication or a very-low-calorie diet is used.
No fixed follow-up interval is specified in the source material. Dietary counselling should be iterative, with progress reviewed and behavioural goals revised over time. The principal measure of success is improvement in overall cardiometabolic health, not weight alone.
