Based on my research, here are the key foods to avoid when you have one kidney and IgAN:

High-sodium foods like:
Processed meats (pepperoni, ham, sausages)
Canned soups
Fast food
Salty snacks

High-potassium foods like:

Potatoes and french fries

Dried fruits (especially prunes)

Bananas

Most beans

Avocados

High-phosphorus foods like:

Ice cream and dairy products

Most nuts

Egg yolks (whites are okay)

Instead, focus on kidney-friendly foods like:
- Cauliflower
- Carrots
- Eggplant
- Egg whites
- White rice
- Fresh lean fish

Always check with your doctor about specific restrictions based on your kidney function.