Nutrition for Common Conditions
Dietary Patterns the Research Supports

What the peer-reviewed evidence says about food and Type 2 diabetes, hypertension, IBS, PCOS, and heart disease — never as a substitute for medical care.

ADA / AHA / NICE Aligned
5 Conditions Covered
Strong Disclaimers
Specialist Referrals

This page is educational information, NOT medical advice

The content below describes dietary patterns that peer-reviewed research has associated with better outcomes for the listed conditions. It is not a treatment protocol. Every condition listed here has individual variability that requires medical assessment. Medications, lab values, organ function, comorbidities, allergies and personal circumstances all change what is safe and effective for you.

Before changing your diet to manage any of these conditions, speak with your physician and (ideally) a registered dietitian. Stopping medication based on a website is dangerous. See the full medical disclaimer.

Type 2 Diabetes

Characterised by insulin resistance and elevated blood glucose. The strongest-evidence dietary patterns are Mediterranean, DASH, low-GI / low-GL, and well-formulated low-carb — all individualised to medications and comorbidities.

Patterns the ADA Endorses

The American Diabetes Association's 2024 Standards of Care state that "there is no single ideal dietary distribution of calories among carbohydrates, fats, and proteins for people with diabetes." Choose a pattern your patient can sustain.

🥬Non-Starchy Veg½ plateLow GL, fiber
🐟Fatty Fish2×/weekOmega-3, no GL
🫘Legumes½ cupSlow-GL carbs
🌰Nuts30g↓HbA1c (modest)
🌾Steel-Cut Oats½ cup dryBeta-glucan
🍓Berries1 cupLow GL fruit
🫒Olive Oilcooking fatMUFA
🌿Cinnamon1 tsp/dayModest BG effect

Limit

Sugar-sweetened beverages — the strongest single dietary risk factor
Refined grains as a meal base (white rice, white bread)
Processed meats (bacon, sausages — independent risk increase)
Ultra-processed snacks regardless of macros
Alcohol on an empty stomach (hypoglycaemia risk on insulin/sulfonylureas)
Talk to your endocrinologist or diabetes educator / RD before changing carb intake on insulin or sulfonylureas — doses need to come down with the food, or hypoglycaemia happens. CGM data + lab work + medication review = the safe pathway.

Hypertension

Persistent BP >130/80 mmHg. The best-studied dietary pattern is DASH (Dietary Approaches to Stop Hypertension); the second is Mediterranean. Both lower systolic BP by 8–14 mmHg in trials — comparable to a single medication.

DASH Pattern in One Glance

4–5
servings
Vegetables / day
4–5
servings
Fruit / day
6–8
servings
Whole grains / day
2–3
servings
Low-fat dairy / day
<1500
mg
Sodium / day (target)
~4700
mg
Potassium / day

Beetroot & Nitrate Foods

Dietary nitrates from beetroot, spinach, arugula, and other leafy greens convert to nitric oxide and modestly lower BP (≈ 4–5 mmHg systolic in meta-analyses). Effect is acute and dose-dependent.

🥬Beetroot Juice200mLNitrates 250mg
🥬Spinach1 cupNitrates + Mg + K
🌿Arugula1 cupHighest leafy nitrate
🍌Banana1 fruitK 422mg
🍠Sweet Potato1 mediumK 542mg

Hidden Sodium Sources

Bread & rolls (often the #1 source — small per-slice, eaten often)
Pizza, sandwiches, soups, processed meats
Restaurant meals (often 50–80% of daily sodium in one meal)
Sauces & condiments (soy sauce, BBQ, salad dressing)
"Reduced-fat" snacks (sodium often added when fat is removed)
Talk to your cardiologist or primary-care physician — never adjust BP medication based on diet changes alone. Home BP monitoring + medication review = the safe pathway. If you have kidney disease, potassium-rich foods may need limiting (the opposite of standard DASH).

Irritable Bowel Syndrome (IBS)

A symptom-based diagnosis — pain + altered bowel habits without structural disease. The best-evidenced dietary intervention is a structured low-FODMAP protocol, done in 3 phases under RD supervision.

The 3 Phases of Low-FODMAP

Phase 1 — Elimination (2–6 weeks): remove all high-FODMAP foods. ~70% of IBS patients improve.
Phase 2 — Reintroduction (6–10 weeks): systematically test each FODMAP category to find personal triggers.
Phase 3 — Personalisation: long-term, the least-restrictive diet that controls symptoms. Most people end up eating MOST FODMAP foods again.

Do NOT stay on elimination long-term

Permanent low-FODMAP starves the gut microbiome — bifidobacteria drop. Phase 1 is diagnostic, not therapeutic. Work with an IBS-trained RD.

Generally Well-Tolerated

🍚Rice (any)1 cupLow FODMAP
🥔Potato1 mediumLow FODMAP
🥕Carrot1 cupLow FODMAP
🥬Spinach1 cupLow FODMAP
🍋Citrus1 fruitLow FODMAP
🍓Strawberries10 berriesLow FODMAP
🍌Unripe Banana1 fruitLow FODMAP (ripe = mod)
🍗Plain Chicken/Fish100gNo FODMAPs (protein)

Common Triggers (High-FODMAP)

Onion, garlic (concentrated fructans — the most common triggers)
Wheat-based bread, pasta in large amounts
Lentils & beans in standard portions
Apple, pear, mango, watermelon
Cow's milk, yogurt, ice cream (lactose)
Honey, agave, sugar-free gum (polyols)
Talk to your gastroenterologist + IBS-trained registered dietitian — IBS shares symptoms with coeliac disease, IBD, and other conditions that need ruling out first. Low-FODMAP done DIY often fails or leads to nutrient deficits; do it with a credentialed RD.

Polycystic Ovary Syndrome (PCOS)

Diagnosis varies — Rotterdam (most common), NIH and AE-PCOS Society criteria require ≥2 of: irregular cycles, hyperandrogenism, polycystic ovaries on ultrasound. ~70% of cases involve insulin resistance, which is the dietary lever.

Anti-Inflammatory + Low-GI Pattern

Strongest evidence: Mediterranean-style + emphasis on lower-glycaemic-index carbs. Modest weight loss (5–10%) when applicable can restore ovulation in many. Endocrine Society guidelines recommend it as first-line.

🥬Leafy Greens2 cups/dayFolate, Mg, fiber
🐟Fatty Fish2×/weekOmega-3 anti-inflam
🫘Legumes½ cupLow GI carbs
🌰Nuts & Seeds30gMg, Zn, MUFA
🍓Berries1 cupLow GI, polyphenols
🌾Whole Grains½ cupSteel oats, quinoa
🌿Cinnamon1 tspModest insulin effect
🫒Olive OilcookingAnti-inflammatory

Inositol — Evidence & Caveats

Myo-inositol (often combined with D-chiro-inositol in a 40:1 ratio) has accumulating evidence for improving insulin sensitivity and ovulation rates in PCOS. The Endocrine Society 2023 guideline accepts it as an option. Discuss dose with your endocrinologist or gynaecologist — it interacts with other medications and isn't well-regulated as a supplement.

Limit

Sugar-sweetened beverages and high-GI desserts
Refined grains as a meal base
Ultra-processed snacks (linked to higher androgen-related symptoms)
Excessive trans fats (margarine spreads, fried fast food)
Talk to your endocrinologist or gynaecologist — PCOS is a syndrome with overlapping conditions (thyroid, prolactin, CAH) that need ruling out. Treatment plans usually combine lifestyle + medication (metformin, hormonal contraceptives) and the choice is personal. Do not start inositol or other supplements without coordinating with your team.

Heart Disease & Cardiovascular Risk

Includes coronary artery disease, post-MI recovery, heart failure, and elevated LDL/triglycerides. AHA's strongest endorsement is the Mediterranean pattern (PREDIMED trial showed 30% reduction in major events).

Mediterranean as Foundation

🫒Extra-Virgin Olive Oil≥ 4 tbsp/dayPREDIMED dose
🌰Mixed Nuts30g/dayPREDIMED dose
🐟Fatty Fish2–3×/weekEPA + DHA
🥬Leafy GreensdailyNitrates, K, fiber
🫘Legumes3–4×/weekSoluble fiber, K
🍓Berries≥ 3×/weekPolyphenols, ↓LDL
🌾Whole GrainsdailyBeta-glucan ↓LDL
🌿Garlic1–2 clovesModest BP/lipid

Specific LDL-Lowering Foods

"Portfolio Diet" foods — each contributes ~5% LDL reduction; combined they rival a low-dose statin in trials.

Soluble fiber (oats, barley, psyllium) — 5–10g/day = ~5% LDL drop
Plant sterols / stanols — 2g/day from fortified spreads
Soy protein — 25g/day (tofu, tempeh, edamame)
Tree nuts — 30g/day

Limit

Trans fats — zero target (avoid partially hydrogenated oils)
Processed meats (bacon, sausage, deli)
Sugar-sweetened beverages
Refined grains as a meal base
Excess sodium (per the hypertension tab)
Talk to your cardiologist or primary-care physician — never stop statins or BP/anticoagulant medication based on diet. If you take warfarin, vitamin K from greens must stay consistent (not avoided — consistent). Cardiac rehab + RD + medication review = the safe pathway.

One more reminder

If any condition on this page applies to you, the single most valuable thing you can do is book time with a registered dietitian (RD/RDN/APD) who works alongside your physician. Most insurance plans cover several sessions a year. Personalised plans beat any internet article, including this one.

See our full terms & medical disclaimer.