What is alkaline food

All foods are alkaline or acid forming, giving them a pH level (potential for Hydrogen) referring to hydrogen ions in water.
A pH range is between 0-14.
7 is neutral, anything below 7 is acidic and above 7 is alkaline.
A healthy pH of the blood is ranged between 7.35 and 7.45

Ideally we should consume 80% alkaline and 20% acid to restore good health.
Otherwise 60/40 to maintain good health.

Examples
Acid forming foods
Dairy, meat, seafood, sugars, yeast, wheat, rice, saturated fats, processed foods, pickled vegetables, berries, eggs, chocolate, most nuts (except almonds), caffeine, black tea, fruit juices and alcohol.

Alkaline forming foods
Fruits & Vegetables- lemon, lime, watermelon, avocado, kale, capsicum, alfalfa, root vegetables, pumpkin, lettuce, asparagus, cauliflower, cabbage, artichoke, radish, wheat grass, sweet potato, cucumber, melons, dates, figs, coconut, pears, sea vegetables, onion, garlic, ginger, lime and herbs
Nuts & Grains- almonds, chestnuts, sesame, buckwheat, spelt, sunflower, flax, millet and sprouted seeds
Oils & Fats- avocado, hemp, evening primrose, borage, coconut, sesame and olive
Drinks- Fresh vegetable juices, herbal tea, green tea, fresh coconut water and almond milk (unsweetened)
Other- most spices, sea salt and stevia (sweetener)

Many Alkaline Food Charts may contradict each other. This is because they may indicate the pH level either before or after ingestion, which changes.
Also a pH level changes from raw to cooked.
E.g. Spinach is alkaline raw but low acidic when cooked, Lemon is acidic and alkaline when ingested.