Alimentazione e nutrizione Diabetes Low GI Potassium Phosphorus

Glycemic Index Food Guide for Diabetic Kidney Patients: Full Low/Medium/High GI Table, Recommended and Not-Recommended Lists, and How to Balance Potassium, Phosphorus and Protein

Beyond CKD 14 ottobre 2026 14 min di lettura

Diabetes plus kidney disease is the hardest diet to manage: control glucose, limit potassium and phosphorus, and get protein just right. This guide lists the GI and glycemic load of 90+ everyday foods, flags which low-GI foods are also low in potassium and phosphorus (truly recommended), which are low-GI but high-potassium (handle with care), and which high-GI foods to avoid — plus pre- vs post-dialysis protein, safe hypoglycaemia treatment and a sample day.

Who this is for: people with diabetes and CKD stages 3–5, diabetic dialysis patients, and transplant recipients with post-transplant diabetes (PTDM). GI values come from the University of Sydney GI database and the 2021 International GI/GL Tables (Atkinson et al.); potassium and phosphorus from USDA FoodData Central. Individual glucose responses vary — check with your meter. This does not replace personalised advice from your dietitian.

1. Three terms to understand

Term	Meaning	Reading
Glycemic index (GI)	How fast and how high glucose rises after 50 g of carbohydrate from a food, with glucose = 100	Low ≤55, medium 56–69, high ≥70
Glycemic load (GL)	GI × grams of carbohydrate per serving ÷ 100 — accounts for portion	Low ≤10, medium 11–19, high ≥20
Net carbs	Total carbohydrate minus fibre	Fibre does not raise glucose

Why GI matters for kidney patients

Low-GI eating lowers HbA1c by about 0.3–0.5%, blunts post-meal spikes and improves triglycerides (Cochrane 2023, ADA 2025).
Post-meal glucose spikes are linked to glomerular hyperfiltration, albuminuria and cardiovascular events.
But GI looks only at carbohydrate — not potassium, phosphorus, protein or sodium. That is the trap: many "healthy low-GI foods" (whole grains, legumes, nuts, sweet potato, banana) are high in potassium or phosphorus. Every item below is therefore tagged for both.

2. What changes a food's GI (use these and you are halfway there)

More processing = higher GI: white rice > brown rice; juice > whole fruit; mashed potato > boiled whole.
Longer cooking = higher GI: rice porridge/congee (~~80–90) far exceeds steamed rice (~~70); pasta al dente is lower.
Cooling creates resistant starch: day-old rice or cooled potatoes drop GI by 10–20%.
Protein, fat, vinegar and fibre eaten together lower the GI of the whole meal.
Eating order: vegetables and protein first, starch last, cuts the post-meal peak by 20–30%.
Ripeness: riper bananas and mangoes have higher GI.

3. Complete table (GI / potassium / phosphorus per serving)

Tags: 🟢 low (K <150 mg, P <100 mg per serving), 🟡 medium (K 150–250, P 100–180), 🔴 high (K >250 or P >180).

A. Staples (grains, roots)

Food	GI	Serving	K	P	Kidney verdict
White rice (short/medium grain)	73	1 bowl 160 g	🟢 50	🟢 60	High GI but the lowest K/P staple; small portion, with protein and vegetables, slightly cooled is the most practical choice
Rice congee	88	1 bowl	🟢	🟢	Not recommended: fastest glucose rise, least filling
Glutinous rice, rice cakes, zongzi	87–98	1 piece	🟢	🟡	Not recommended: among the highest GI
Brown rice	68	1 bowl	🟡 150	🔴 200	Lower GI but high P/K; on dialysis limit to half a bowl 2–3×/week
Multigrain rice	55–65	1 bowl	🔴	🔴	As above, even more phosphorus
Rolled oats (traditional)	55	40 g dry	🟡 150	🔴 170	Low GI but high P; instant oats GI 79 not recommended
Soba (100% buckwheat)	46–54	1 serving	🟡	🔴	Low GI, medium K, high P; occasionally
Wheat noodles, udon	55–62	1 serving	🟢	🟢	Recommended: medium-low GI, low K/P; cook firm
Pasta (al dente)	45–50	1 serving	🟢	🟡	Recommended: low GI, low K
Glass noodles (mung bean)	39	1 serving	🟢	🟢	Recommended: one of the lowest-GI staples
Rice vermicelli	58–61	1 serving	🟢	🟢	Acceptable
White bread	75	1 slice	🟢	🟢	High GI; if eaten, pair with egg or meat
Wholemeal bread	69–74	1 slice	🟡	🟡	"Wholemeal" GI is not actually low and P is higher — limited advantage
Rye sourdough	48–55	1 slice	🟡	🟡	Recommended: fermentation lowers GI
Steamed bun (mantou)	80+	1	🟢	🟢	Not recommended
Potato (boiled, hot)	78–82	1 × 150 g	🔴 600	🟡	Not recommended: high GI and high K; slicing, soaking and boiling removes 30–50% K; cooling lowers GI
Sweet potato (steamed)	63–70	1 × 130 g	🔴 450	🟡	High K; less glucose-friendly than its reputation; caution on dialysis
Taro	53	100 g	🔴 500	🟡	Low GI but very high K; not recommended on dialysis
Yam (Chinese)	51–54	100 g	🔴	🟡	As above
Pumpkin	64–75	100 g	🔴 340	🟡	High GI and K; small amounts
Sweet corn	52	half cob	🟡	🟡	Acceptable — count as a staple, not a vegetable
Lotus root	33	100 g	🔴	🟡	Low GI but high K

B. Legumes and protein foods

Food	GI	Serving	K	P	Kidney verdict
Egg	0	1	🟢 70	🟡 95	Recommended: high-quality protein, controllable P
Chicken breast, fish, pork loin	0	palm-size 100 g	🔴 300–400	🔴 200	Essential protein; 1.0–1.2 g/kg/day on dialysis, 0.6–0.8 g/kg in CKD 3–4; "organic" phosphorus in meat is only 40–60% absorbed — far better than additive phosphate
Firm tofu	15	150 g	🟡 180	🟡 150	Recommended: low GI, plant protein, poorly absorbed P
Unsweetened soy milk	30	240 mL	🟡 280	🟡 120	Acceptable; watch K; 1 cup/day
Soybeans, black beans (cooked)	15–20	half cup	🔴 450	🔴 220	Low GI but high K/P; small amounts on dialysis
Adzuki, mung beans (unsweetened)	25–35	half cup	🔴 300+	🔴	As above; sweetened bean soups are higher GI
Chickpeas, lentils	28–36	half cup	🔴	🔴	As above
Edamame	18	half cup	🔴 450	🟡	Very high K; occasional small portion
Nuts (almonds, walnuts)	0–15	10 nuts	🟡	🔴	Low GI, good fats, but high P; ≤10/day
Milk (whole/low-fat)	30–40	240 mL	🔴 350	🔴 230	Low GI but high K and P; ≤half cup/day on dialysis
Plain yoghurt	35	150 g	🟡	🟡	Somewhat better than milk; still measure
Cheese	0	1 slice	🟢	🔴	High P (processed slices contain phosphate additives)

C. Fruit

Food	GI	Serving	K	P	Kidney verdict
Apple	36–40	1 small	🟡 150	🟢	Recommended
Guava	31–38	half	🟡 230	🟢	Recommended: low GI; half a fruit is enough
Pear	38	1 small	🟡	🟢	Recommended
Strawberries, blueberries	40–53	10	🟢	🟢	Recommended
Orange	43	1	🟡 230	🟢	Acceptable; orange juice has 450 mg K/cup and GI 50+ — not recommended
Grapefruit	25	half	🟡	🟢	Very low GI but forbidden after transplant (interacts with tacrolimus/ciclosporin)
Kiwi	50–58	1	🟡 230	🟢	Medium GI, medium K
Peach, plum	28–42	1	🟡	🟢	Acceptable
Cherries	22	10	🟡	🟢	Acceptable
Papaya	56–60	half cup	🟡	🟢	Medium GI, acceptable
Pineapple	59–66	half cup	🟢 110	🟢	Medium GI but low K — a good fruit on dialysis
Banana (yellow)	51–62	1	🔴 420	🟢	Medium GI but high K; not recommended on dialysis; also not ideal for hypos (slow)
Mango	51–60	half	🟡	🟢	Medium GI; keep portions small
Lychee, longan	57–79	10	🟡	🟢	Sugary, higher GI; small amounts
Watermelon	72–80	1 cup	🟡	🟢	High GI but low GL (mostly water); one cup is fine
Cantaloupe/rock melon	65–70	1 cup	🔴	🟢	High GI and K; not recommended
Custard apple, durian	54–60	small	🔴	🟡	High sugar and K; not recommended
Raisins, dates, dried fruit	64–103	30 g	🔴	🟡	Not recommended: concentrated sugar and K
All fruit juices	45–70	1 cup	🔴	🟢	Not recommended: no fibre, concentrated K

D. Vegetables

Food	GI	Serving	K	P	Kidney verdict
Leafy greens (cabbage, bok choy, lettuce)	<15	1 cup cooked	🟡	🟢	Recommended: blanch 3 min and discard water to remove 30–40% K
Cauliflower, broccoli	15	1 cup	🟡	🟢	Recommended (blanched)
Cucumber, zucchini	15	1 cup	🟢	🟢	Recommended: among the lowest-K vegetables
Bell peppers	15	1 cup	🟡	🟢	Recommended
Onion	10–15	half cup	🟢	🟢	Recommended
Eggplant	15	1 cup	🟡	🟢	Acceptable
Tomato	15–38	1	🟡 240	🟢	Acceptable; paste and sauce concentrate K
Carrot (cooked)	39–49	half cup	🟡	🟢	Acceptable (the old "high GI" figure is outdated)
Mushrooms	<15	1 cup	🟡	🟡	Acceptable; slightly higher P
Spinach, amaranth, water spinach	<15	1 cup cooked	🔴 500+	🟢	Low GI but very high K; must blanch and limit on dialysis
Bamboo shoots	<15	1 cup	🔴	🟢	High K
Kelp, seaweed	<15	small	🔴	🟡	Very high K; tiny amounts
Burdock	45	half cup	🔴	🟢	High K

E. Snacks, drinks, sweeteners

Food	GI	Kidney verdict
Sugary drinks, bubble tea	60–80	Not recommended: sugar, phosphoric acid (cola), tapioca pearls
Unsweetened tea, black coffee	0	Recommended; coffee ≤2 cups/day (115 mg K per cup)
Crackers, rice crackers	70–90	Not recommended: high GI, sodium, phosphate
Cake, doughnuts, pastries	60–76	Not recommended
Dark chocolate ≥70%	23	Small amount (10 g); medium K/P
Potato chips	55–60	High K and sodium, not recommended
Honey	58–61	Sugar is sugar
Sweeteners (erythritol, monk fruit, stevia, aspartame, sucralose)	0	Fine; sugar alcohols cause diarrhoea in excess; do not harm kidneys (common myth)
Maltodextrin (in many "sugar-free" products)	85–105	Higher GI than glucose — read labels
"Sugar-free"/"low-sugar" baked goods	often >60	Sugar-free ≠ carb-free; starch still raises glucose

4. At a glance: truly recommended vs. truly avoid

✅ Truly recommended — low GI AND low K/P

Glass noodles, pasta (al dente), udon, rye sourdough, firm tofu, eggs, apple, guava (half), pear, berries, pineapple, cherries, cucumber, bell pepper, onion, blanched cabbage, cauliflower, unsweetened tea and coffee, non-nutritive sweeteners.

⚠️ Low GI but high K or P — allowed, measured

Brown rice, oats, legumes, nuts, milk, yoghurt, sweet potato, taro, yam, lotus root, spinach, tomato, orange, kiwi, soy milk, dark chocolate.

❌ Avoid — high GI, or high GI + high K + high P

Congee, glutinous rice products, steamed buns, white bread, instant oats, mashed potato, pumpkin, cantaloupe, banana, dried fruit, all juices, sugary drinks, pastries, rice crackers, chips, cola (phosphoric acid), processed meats (phosphate additives).

5. Special rules for diabetic kidney patients

1. Protein — opposite directions before and after dialysis

CKD 3–4 (pre-dialysis): 0.6–0.8 g/kg/day, favouring high-biological-value protein (egg, fish, lean meat, tofu). Low protein but not low calorie — energy deficit breaks down muscle.
Dialysis: 1.0–1.2 g/kg/day because amino acids are lost in dialysate. Diabetic dialysis patients are at particularly high risk of malnutrition.
When carbohydrate is cut, replace the energy with healthy fats (olive oil, a little avocado, canola), not unlimited protein.

2. Treating hypoglycaemia — not juice, not banana

Take 15 g fast sugar: 3–4 glucose tablets, 3 sugar cubes, 1 tablespoon honey, or 150 mL regular cola (occasionally).
Re-test after 15 minutes; repeat if still <70 mg/dL (3.9 mmol/L).
Avoid orange juice and banana (high K) and chocolate (fat slows absorption).
Hypos are commonest on dialysis days; a small complex-carb snack (half slice of bread with egg) before the session helps.

3. Peritoneal dialysis

Dialysate glucose adds 100–200 kcal/day (25–50 g of sugar); reduce dietary carbohydrate accordingly and ask about icodextrin.

4. Transplant recipients

No grapefruit, pomelo or starfruit; starfruit is neurotoxic for all kidney patients.
Steroids push post-lunch and afternoon glucose highest; many patients front-load carbohydrate at breakfast and cut starch at lunch and dinner.
Potassium and phosphorus limits usually relax after transplant — whole grains and legumes can return gradually, guided by blood tests.

5. Sodium

<2,000 mg/day (5 g salt). Salt → thirst → fluid → interdialytic weight gain. Many "low-GI" packaged foods (whole-grain crackers, cereal bars) are high in sodium and phosphate.

6. Phosphate additives

Ingredients such as "phosphoric acid", "sodium pyrophosphate", "polyphosphate", "E338–E452" are 90–100% absorbed — far more harmful than natural phosphorus. Found in cola, processed meat, cheese slices, frozen ready meals and instant noodles.

6. Sample day (on dialysis, 60 kg, ~150–180 g carbohydrate)

Meal	Food	Notes
Breakfast	1 slice rye sourdough + 2 scrambled eggs + cucumber slices + black coffee	~20 g carb, 14 g protein, low K
Lunch	2/3 bowl white rice (cooled 10 min) + 100 g steamed fish + 1 cup blanched cabbage (water discarded) + stir-fried peppers and onion	Vegetables and fish first, rice last
Snack	Half a guava or 1 small apple	GI <40
Dinner	80 g (dry) pasta al dente + 100 g chicken breast in olive oil and garlic + zucchini	Low GI, low K
Evening (if needed)	100 g cold tofu or half cup plain yoghurt	Protein-led

Approximate totals: carbohydrate 160 g, protein 70 g (1.15 g/kg), potassium ~1,900 mg, phosphorus ~900 mg (taken with phosphate binders). Adjust with your dietitian according to your blood results.

7. Common myths

"Sweet potato is healthier than white rice" — true for diabetes alone; on dialysis, sweet potato has 9× the potassium of white rice for only a slightly lower GI.
"Wholemeal bread is low GI" — commercial wholemeal has GI 69–74, barely below white; only dense rye sourdough and whole-kernel breads are genuinely low.
"Fruit sugar is natural, so it's fine" — fructose raises glucose slowly but raises triglycerides; cap fruit at 2 fist-sized portions a day, and juice does not count as fruit.
"Sweeteners damage the kidneys" — no evidence of nephrotoxicity for approved sweeteners; a 2023 observational link between erythritol and cardiovascular events remains unconfirmed — moderation is enough.
"Diabetics can't eat rice" — white rice is one of the safest staples for kidney patients because of its low K/P; the issue is portion and pairing, not the rice itself.

Sources

Atkinson FS, Brand-Miller JC, et al. International tables of glycemic index and glycemic load values 2021. Am J Clin Nutr 2021;114:1625–1632.
The University of Sydney. GI Database. https://glycemicindex.com/
American Diabetes Association. Standards of Care in Diabetes—2025, Section 5 (Nutrition). Diabetes Care 2025;48(Suppl 1).
KDIGO. 2022 Clinical Practice Guideline for Diabetes Management in CKD — nutrition section. Kidney Int 2022;102(5S).
Ikizler TA, et al. KDOQI Clinical Practice Guideline for Nutrition in CKD: 2020 Update. Am J Kidney Dis 2020;76(3 Suppl 1):S1–S107.
Chiavaroli L, et al. Effect of low glycaemic index or load dietary patterns on glycaemic control in diabetes. BMJ 2021;374:n1651.
USDA. FoodData Central. https://fdc.nal.usda.gov/
National Kidney Foundation. Diabetes and Kidney Disease: What to Eat? https://www.kidney.org/atoz/content/Diabetes-and-Kidney-Disease-What-to-Eat

Leggi in un'altra lingua: English 日本語繁體中文