7.4, give or take .1, is the perfect pH for the body. Newborn babies and healthy people have slightly alkaline pH. As the body matures, its pH slowly becomes more acidic. Studies show that 85% of cancer patients have a low (acidic) pH. The best way to keep your body's pH healthy is to keep it slightly alkaline. People with more acidic pH are characterized by fatigue, low metabolism, overweight, large abdomen, pale skin, cold hands/feet, itchy feet, low energy capacity, lots of yawning, neck/shoulder discomfort, poor circulation, thickened blood, and sleep/breathing difficulty. All of these symptoms go hand in hand: thickened blood does not flow well, especially through the thinner veins in one's hands and feet, resulting in cold hands/feet and poor circulation, which results in fatigue and other energy-related symptoms. If you are keeping an eye on your weight, it is important to maintain a healthy alkaline pH so that you don't experience weight gain and those other symptoms.
pH is affected by diet and stress. Too much meat, dairy products, and egg yolk can acidify your pH, as can emotional stress (overthinking, worry, fear, etc.). Here is a small list of foods according to their pH (see the appendix in the back for a complete list):
Acidic foods (from most acidic to least): egg yolk, cheese, sugar, cookies (sugary), fish eggs, bacon, ham, chicken, pork, beef, bread, pasta, noodles, wheat, butter, rice, peanuts, beer, hard liquor, fried foods, clams, shellfish.
Alkaline foods (from least alkaline to most): red bean, white radish, apple, broccoli, Spanish onion, tofu & tofu products, soybean, carrot, tomato, banana, egg white, lemon, chicory, cilantro, watercress, spinach, bitter melon, watermelon, grape, tea (green/black), red wine, seaweed, kelp, natural green algae.
A meal with some foods from both categories falls into whichever category it contains more of. For example, a meal with a small amount of chicken (acidic) and a large amount of spinach (alkaline) is an alkaline meal. Ideally, you should eat 20-30% acidic foods and 70-80% alkaline foods. A meal with some meat (most of which tends to be acidic) and a lot of vegetables (most of which tend to be alkaline) is a meal that is overall healthy for your pH. For example, a soup containing tofu, seaweed, egg white, and chicken is good: the meat helps fill you, but most of the soup is still alkaline.