What food is best for a normal person to maintain health?

For adults

A healthy diet includes the following:

Fruit, vegetables, legumes (e.g. lentils and beans), nuts and whole grains (e.g. unprocessed maize, millet, oats, wheat and brown rice).
At least 400 g (i.e. five portions) of fruit and vegetables per day (2), excluding potatoes, sweet potatoes, cassava and other starchy roots.
Less than 10% of total energy intake from free sugars (2, 7), which is equivalent to 50 g (or about 12 level teaspoons) for a person of healthy body weight consuming about 2000 calories per day, but ideally is less than 5% of total energy intake for additional health benefits (7). Free sugars are all sugars added to foods or drinks by the manufacturer, cook or consumer, as well as sugars naturally present in honey, syrups, fruit juices and fruit juice concentrates.
Less than 30% of total energy intake from fats (1, 2, 3). Unsaturated fats (found in fish, avocado and nuts, and in sunflower, soybean, canola and olive oils) are preferable to saturated fats (found in fatty meat, butter, palm and coconut oil, cream, cheese, ghee and lard) and trans-fats of all kinds, including both industrially-produced trans-fats (found in baked and fried foods, and pre-packaged snacks and foods, such as frozen pizza, pies, cookies, biscuits, wafers, and cooking oils and spreads) and ruminant trans-fats (found in meat and dairy foods from ruminant animals, such as cows, sheep, goats and camels). It is suggested that the intake of saturated fats be reduced to less than 10% of total energy intake and trans-fats to less than 1% of total energy intake (5). In particular, industrially-produced trans-fats are not part of a healthy diet and should be avoided (4, 6).
Less than 5 g of salt (equivalent to about one teaspoon) per day (8). Salt should be iodized.

For infants and young children

In the first 2 years of a child’s life, optimal nutrition fosters healthy growth and improves cognitive development. It also reduces the risk of becoming overweight or obese and developing NCDs later in life.

Advice on a healthy diet for infants and children is similar to that for adults, but the following elements are also important:

Infants should be breastfed exclusively during the first 6 months of life.
Infants should be breastfed continuously until 2 years of age and beyond.
From 6 months of age, breast milk should be complemented with a variety of adequate, safe and nutrient-dense foods. Salt and sugars should not be added to complementary foods.

Water

Drink 8 to 12 cups of water daily.

Dark Green Vegetables

Eat dark green vegetables at least three to four times a week. Good options include broccoli, peppers, brussel sprouts and leafy greens like kale and spinach.

Whole Grains

Eat whole grains sat least two or three times daily. Look for whole wheat flour, rye, oatmeal, barley, amaranth, quinoa or a multigrain. A good source of fiber has 3 to 4 grams of fiber per serving. A great source has 5 or more grams of fiber per serving.

Beans and Lentils

Try to eat a bean-based meal at least once a week. Try to add legumes, including beans and lentils, to soups, stews, casseroles, salads and dips or eat them plain.

Fish

Try to eat two to three serving of fish a week. A serving consists of 3 to 4 ounces of cooked fish. Good choices are salmon, trout, herring, bluefish, sardines and tuna.

Berries

Include two to four servings of fruit in your diet each day. Try to eat berries such as raspberries, blueberries, blackberries and strawberries.

Winter Squash

Eat butternut and acorn squash as well as other richly pigmented dark orange and green colored vegetables like sweet potato, cantaloupe and mango.

Soy

25 grams of soy protein a day is recommended as part of a low-fat diet to help lower cholesterol levels. Try tofu, soy milk, edamame soybeans, tempeh and texturized vegetable protein (TVP).

Flaxseed, Nuts and Seeds

Add 1 to 2 tablespoons of ground flaxseed or other seeds to food each day or include a moderate amount of nuts – 1/4 cup – in your daily diet.

Organic Yogurt

Men and women between 19 and 50 years of age need 1000 milligrams of calcium a day and 1200 milligrams if 50 or older. Eat calcium-rich foods such as nonfat or low-fat dairy products three to four times a day. Include organic choices.