Nutrition

1. Nutrition • Plants are the only terrestrial organisms that convert inorganic carbon, oxygen, hydrogen, nitrogen, and sulfur to organic forms, via photosynthesis. • They are called autotrophs (meaning “self-feeder”). • Humans, and just about everything else that live on land are heterotrophs (or “other feeders”). • Because they feed off autotrophs or other heterotrophs.

2. Nutrition • Only a small percentage of all the plant species in existence feed the world’s people: • Cereal crops—wheat, maize (corn), rice, barley, oats, sorghum, rye, millet. • Over half the world’s food supply come from these crops. • Roots & tubers—potatoes, sweet potatoes, cassavas. • Oil crops—soybeans, corn, peanuts, palm, coconuts, sunflowers, olive, safflower. • Sugar—sugar cane & sugar beets. • Fruit crops—bananas, oranges, apples, pears, etc. • Vegetable crops—tomatoes, lettuce, carrots, melons, asparagus, etc.

3. Nutrition Common crops ranked in relation to the calories and proteins produced per unit of land area. Not all of the total productionof food materials is available for human consumption. Much is lost during harvesting, transportation, and marketing. Some of the production is saved to be used as seedfor future plantings.

4. Twenty-four to thirty-six slices of bread is one way to get our daily energy requirement. Lipids provide energy in more condensed form. Nutrition Adults need 2000 to 3000 kcal of energy per day, depending on their size and level of activity. This energy can be provided by carbohydrates,typically found in plant foods.

5. Nutrition • Animal fats tend to be saturated fats, which lack double bonds in their fatty acids. • Plant energy carbohydrate sources are healthy as they are associated with indigestible fiber, which protects from colon disorders. • Purified carbohydrates such as refined sugar or starchare not as beneficial, and carry their own health risks.

6. An adult needs about 70 grams of protein in a day. Plant foods, especially cereal grains and pulses (peas & beans),often provide enough protein along with the energy they supply. Nutrition

7. Nutrition • A plant diet may not satisfy protein requirements,as it may be deficient in one or more amino acids. • Plant proteins often have a low proportion of essential amino acids • An exception is quinoa (Chenopodium quinoa). • Animals generally provide better-quality protein. • Eggs are generally regarded as providing perfect protein. • Deficiencies of individual plant foods can be remedied to a large extent by combining them. • A balance can also be achieved on a plant dietwith a small amount of meat or other animal food.

8. Nutrition • Carbohydrates, lipids (fats), and proteins are thebulk constituents of our diet. • We also need small amounts organic molecules—vitamins. • Most can be obtained from fruits, vegetables, or grains.

9. Nutrition • Vitamin C is found only in fresh fruits and vegetables. • Vitamin Ais derived from carotene, found in green, yellow, orange, or red fruits, vegetables, and grains. • Vitamin B12 is not provided by plants. • Cyanocobalamin is manufactured by bacteria, especiallyin ruminant organisms, is available in meat & dairy foods. • We require six major inorganic nutrients—calcium, phosphorus, magnesium, sodium, potassium, chloride—and seven micronutrients. • All can be obtained from plant foods, althoughoften more abundant in animal foods.

10. Nutrition • Worldwide there are about 0.25 hectares (0.6 acres) of cropland for each person. • With realistic inputs/yields, this is about enough to provide everyone with a vegetarian diet. • In addition to land required to grow crops, we should count area needed to provide inputs of energy and chemicals, and absorb the wastes generated.

11. Nutrition • Crop production has become concentrated and specialized in regions & countries around the world. • California and Florida produce more than 60% of U.S. grown fruits and vegetables. • Crops can move thousands of miles from producer to consumer.

12. Nutrition • Some argue—from an ecological perspective—that we should consume local produce. • However, energy costs of transport are much lowerthan for out-of-season production in a greenhouse. • Nutrient flow from food transport presents problems. • The nutrients in the produce are removed from the area where the crop was grown.

13. Nutrition • In moist, temperate parts of the world, it is easy to forget how much water is needed to produce crops. • It can take a ton of water to produce a kilogram of grain. • In dry areas, a large land surface may be needed to collect water to be used for irrigation to grow crops. • Water needs in arid locations cause political problems.