See how good your nutrition knowledge is by trying to figure out which food has the most of each nutrient.
Which food has the most fiber?
- Raspberries (1 cup)
- Black beans (1 cup)
- Almonds (1 cup)
- Lentils (1 cup)
Answer: Almonds are the highest, with 17 grams, lentils are a close second, at 16 g, and black beans and raspberries weigh in at 8 g per cup. Other rich sources include whole-wheat flour (14.6 g), broccoli (5 g) and blueberries (3.5 g per cup).
Daily Need: 30 to 38 grams for men and 21 to 25 grams for women.
Why It Matters: Fiber is loaded with health benefits it reduces your risk of heart disease and diabetes and lowers cholesterol. Plus, foods with fiber help to keep you fuller longer. The problem is that most people don't get enough fiber in their diet.
Which food has the most potassium?
- Avocado (1 cup sliced)
- Papaya (1 large)
- Cantaloupe (1/2 large melon)
- Tomato sauce (1 cup)
Answer: One large papaya is surprisingly rich in potassium, with 1,421 milligrams. Cantaloupe is also a surprise, at 1,087 mg. Avocados have 708 mg, and tomato sauce has 811 mg. Other sources include raisins (1,086 mg of potassium per cup), potatoes (1,081 mg), bananas (537 mg) and, yes, even cucumbers (442 mg each).
Daily Need: 4,700 mg
Why It Matters: Potassium is necessary for muscle contractions (including your heartbeat), transmission of nerve impulses and the regulation of fluids and electrolytes. Diets rich in potassium blunt the adverse effects of salt on blood pressure (one in five Americans has high blood pressure), may reduce the risk of developing kidney stones and may decrease bone loss. More than 90 percent of Americans are not meeting their recommended daily need.
Which food has the most iron?
- Kidney beans, cooked (1 cup)
- White mushrooms, boiled (1 cup)
- Pumpkin seeds (1 ounce)
- Chickpeas / hummus (1 cup)
Answer: Chickpeas are the highest, at 4.74 mg per cup, then the kidney beans, at 3.93 mg, the mushrooms, at 2.71 mg, and last the pumpkin seeds, at 2.29 mg. Other sources of iron include clams (23.77 mg in 3 ounces), black beans (3.61 mg per cup) and prune juice (3.02 mg per cup).
Daily Need: Men should be getting 8 mg per day and women 18 mg.
Why It Matters: Iron is an essential component of hemoglobin, which carries oxygen in the blood, and myoglobin, which carries oxygen in muscle tissue. It also helps regulate cell growth and differentiation. Many women are deficient in iron. If you don't get enough, the deficiency limits oxygen delivery to the cells, resulting in fatigue, poor work performance and decreased immunity.
Which food has the most magnesium?
- Almonds (1 ounce)
- Potato, baked with skin (1 medium)
- Banana (1 medium)
- Raisins, seedless ( 1/2 cup packed)
Answer: One ounce of almonds has the most, with 80 mg. A potato is second, with 48 mg. Next is the banana, at 32 mg, and finally the raisins, at 26 mg. Other, even higher, sources of magnesium are buckwheat flour (301 mg per cup), halibut (170 mg), 1 cup of spinach (157 mg) and black beans (120 mg).
Daily Need: Men should get 400 to 420 mg and women 310 to 320 mg daily.
Why It Matters: Magnesium helps maintain normal muscle and nerve function, keeps heart rhythm steady, supports a healthy immune system and keeps bones strong. Magnesium also helps regulate blood sugar levels, promotes normal blood pressure and is involved in energy metabolism and protein synthesis.
Which food has the most calcium?
- Kale, fresh, cooked (1 cup)
- Broccoli, raw (1 medium stalk)
- Spinach, cooked (1 cup)
- Collards, boiled (1 cup)
Answer: Collards are the highest, at 266 mg, then the spinach, at 245 mg, broccoli, at 106 mg, and kale, at 94 mg. Other sources include ricotta cheese (669 mg per cup), yogurt (448 mg a cup) and skim milk (299 mg in a cup).
Daily Need: Men and women ages 19 to 50 need 1,000 mg per day, and people ages 51 and up need 1,200 mg.
Why It Matters: Calcium is famous for building and maintaining strong bones, but it also plays a role in blood clotting, blood pressure regulation and muscle and nerve functioning. Inadequate calcium can result in bone deformities, muscle cramps, hypertension and osteoporosis, which is characterized by fragile bones and increased risk of bone fractures.
Which food has the most vitamin D?
- Salmon (sockeye) cooked (3 ounces)
- Shiitake mushrooms (1 cup)
- Egg, hard-boiled (1 large)
- Milk (1 cup)
Answer: Believe it or not, milk has little or no vitamin D 5 iu (international units) per cup. The shiitake mushrooms have about 45 iu, and the egg has 27 iu, but the sockeye salmon has the most, at 447 iu keep in mind that only sockeye salmon has vitamin D.
Daily Need: Men and women ages 14 through 70 need about 600 iu, or 15 mcg, per day. Also, see: www.ajcn.org/content/88/2/570S.full.
Why It Matters: Vitamin D is unique in that it's found in food but can also be made in your body after exposure to ultraviolet (UV) rays from sunlight. The major biologic function of vitamin D is to maintain normal blood levels of calcium and phosphorus. By promoting calcium absorption, vitamin D helps to form and maintain strong bones. It also works in concert with a number of other vitamins, minerals and hormones to promote bone mineralization. Vitamin D is associated with decreased occurrence of fractures when taken with calcium. It was previously thought that many of us were not getting enough vitamin D; however, recent research has not supported that notion. Typically, 15 minutes in the sunlight will be just fine, but during the winter months (or if you don't get out much), you should consider food sources (not supplements, unless a physician advises you to do so).
CHARLES PLATKIN, Ph.D., M.P.H., is a nutrition and public health advocate and founder of DietDetective.com. Copyright 2012 by Charles Stuart Platkin. All rights reserved. Sign up for the free Diet Detective newsletter at DietDetective.com.