A placebo-controlled double-blind study. Lesson 5 - Oogenesis: Reprinted in Nutrition Mar—Apr;5 2: How much less cancer are we talking about? Every module is like a piece of a puzzle. Lesson 10 - Vitamins We Need: Take quizzes and exams.
Consuming adequate amounts of essential vitamins, minerals, carbohydrates, fiber and protein, while limiting unhealthy fats, processed foods and added sugar, is just as important at this stage of life as it is during childhood. Overall, a healthy diet that incorporates whole grains, fruits, vegetables, lean protein and nonfat and low-fat dairy products should meet all of an adult's nutritional needs.
For adults, weight management can be a major nutrition-related concern and a key factor in achieving health and wellness. In order to remain healthy, adults must be aware of changes in their energy needs, based on their level of physical activity, and then balance their calorie intake as needed. Adults who are active in sports or other physical activities may require more calories than adults who are less active. Caloric intake for adult women should be 1, to 2, calories a day and adult men should consume 2, to 2, calories depending on age and activity level.
You should avoid trans fats when possible, while choosing healthier fats, such as monounsaturated and polyunsaturated. Foods that include these types of fats would be nuts, seeds, fish and vegetable oils. Cholesterol intake should be less than mg per day. In addition, adult males require more of vitamins C, K, B1, B2, B3 and zinc, while women require more iron.
Furthermore, pregnant women should increase their diet by calories per day starting in the second trimester, while lactating women should add an additional calories a day to their typical pre-pregnancy diet. Both pregnant and lactating women should make sure they consume adequate amounts of folic acid, iron and zinc.
Get access risk-free for 30 days, just create an account. In summary, by the time you reach adulthood, the majority of your growth and development will be complete. With regards to nutrition, the focus should now be on maintaining a healthy and active lifestyle and preventing diet-related health problems , such as cardiovascular disease, hypertension and type 2 diabetes. Adults should maintain a diet that incorporates whole grains, fruits, vegetables, lean protein and low-fat or non-fat dairy products, while limiting unhealthy fats, processed foods and sugar.
Weight management can be a major nutrition-related concern for adults and a key factor in achieving health and wellness. In order to remain healthy, adults must be aware of changes in their level of physical activity and balance their calorie intake as needed.
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By creating an account, you agree to Study. Explore over 4, video courses. Find a degree that fits your goals. Nutrition Needs During Adulthood In this lesson, you will learn about nutritional requirements during adulthood. You will also gain an understanding of nutrition-related concerns facing grown-ups, as well as daily dietary recommendations for adults.
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Factors that Influence Dietary Choices: What Are Fat-Soluble Vitamins? Physical, Psychological and Emotional Changes in Adults. What is Anthropometric Measurement? Lipids Digestion and Absorption.
Eutrophication arises from the oversupply of nutrients, which leads to overgrowth of plants and algae. After such organisms die, the bacterial degradation of their biomass consumes the oxygen in the water, thereby creating the state of hypoxia. According to Ullmann's Encyclopedia, "the primary limiting factor for eutrophication is phosphate. Phosphorus is a necessary nutrient for plants to live, and is the limiting factor for plant growth in many freshwater ecosystems.
Phosphate adheres tightly to soil, so it is mainly transported by erosion. Once translocated to lakes, the extraction of phosphate into water is slow, hence the difficulty of reversing the effects of eutrophication. Cultural eutrophication is the process that speeds up natural eutrophication because of human activity.
Extra nutrients are also supplied by treatment plants, golf courses, fertilizers, farms including fish farms , as well as untreated sewage in many countries. When algae die, they decompose and the nutrients contained in that organic matter are converted into inorganic form by microorganisms. This decomposition process consumes oxygen, which reduces the concentration of dissolved oxygen. The depleted oxygen levels in turn may lead to fish kills and a range of other effects reducing biodiversity.
Nutrients may become concentrated in an anoxic zone and may only be made available again during autumn turn-over or in conditions of turbulent flow. Enhanced growth of aquatic vegetation or phytoplankton and algal blooms disrupts normal functioning of the ecosystem, causing a variety of problems such as a lack of oxygen needed for fish and shellfish to survive.
The water becomes cloudy, typically coloured a shade of green, yellow, brown, or red. Eutrophication also decreases the value of rivers, lakes and aesthetic enjoyment. Health problems can occur where eutrophic conditions interfere with drinking water treatment. Human activities can accelerate the rate at which nutrients enter ecosystems.
Runoff from agriculture and development, pollution from septic systems and sewers , sewage sludge spreading, and other human-related activities increase the flow of both inorganic nutrients and organic substances into ecosystems. Elevated levels of atmospheric compounds of nitrogen can increase nitrogen availability.
Phosphorus is often regarded as the main culprit in cases of eutrophication in lakes subjected to "point source" pollution from sewage pipes. The concentration of algae and the trophic state of lakes correspond well to phosphorus levels in water. Studies conducted in the Experimental Lakes Area in Ontario have shown a relationship between the addition of phosphorus and the rate of eutrophication. Humankind has increased the rate of phosphorus cycling on Earth by four times, mainly due to agricultural fertilizer production and application.
Between and , an estimated ,, tonnes of phosphorus was applied to Earth's surface, primarily on croplands. Although eutrophication is commonly caused by human activities, it can also be a natural process, particularly in lakes. Eutrophy occurs in many lakes in temperate grasslands, for instance. Paleolimnologists now recognise that climate change, geology, and other external influences are critical in regulating the natural productivity of lakes.
Some lakes also demonstrate the reverse process meiotrophication , becoming less nutrient rich with time. Eutrophication is a common phenomenon in coastal waters. In contrast to freshwater systems, nitrogen is more commonly the key limiting nutrient of marine waters; thus, nitrogen levels have greater importance to understanding eutrophication problems in salt water.
Estuaries tend to be naturally eutrophic because land-derived nutrients are concentrated where run-off enters a confined channel. Upwelling in coastal systems also promotes increased productivity by conveying deep, nutrient-rich waters to the surface, where the nutrients can be assimilated by algae. Examples of anthropogenic sources of nitrogen-rich pollution include seacage fish farming and discharges of ammonia from the production of coke from coal. In addition to runoff from land, fish farming wastes and industrial ammonia discharges, atmospheric fixed nitrogen can enter the open ocean.
Terrestrial ecosystems are subject to similarly adverse impacts from eutrophication. Many terrestrial plant species are endangered as a result of soil eutrophication, such as the majority of orchid species in Europe. In meadows, tall grasses that can take advantage of higher nitrogen levels may change the area so that natural species may be lost. Species-rich fens can be overtaken by reed or reedgrass species. Forest undergrowth affected by run-off from a nearby fertilized field can be turned into a nettle and bramble thicket.
Chemical forms of nitrogen are most often of concern with regard to eutrophication, because plants have high nitrogen requirements so that additions of nitrogen compounds will stimulate plant growth. Nitrogen is not readily available in soil because N 2 , a gaseous form of nitrogen, is very stable and unavailable directly to higher plants. Terrestrial ecosystems rely on microbial nitrogen fixation to convert N 2 into other forms such as nitrates.
However, there is a limit to how much nitrogen can be utilized. Ecosystems receiving more nitrogen than the plants require are called nitrogen-saturated. Saturated terrestrial ecosystems then can contribute both inorganic and organic nitrogen to freshwater, coastal, and marine eutrophication, where nitrogen is also typically a limiting nutrient.
However, because phosphorus is generally much less soluble than nitrogen, it is leached from the soil at a much slower rate than nitrogen. Consequently, phosphorus is much more important as a limiting nutrient in aquatic systems.
Eutrophication was recognized as a water pollution problem in European and North American lakes and reservoirs in the midth century. Many ecological effects can arise from stimulating primary production , but there are three particularly troubling ecological impacts: When an ecosystem experiences an increase in nutrients, primary producers reap the benefits first. In aquatic ecosystems, species such as algae experience a population increase called an algal bloom. Algal blooms limit the sunlight available to bottom-dwelling organisms and cause wide swings in the amount of dissolved oxygen in the water.
Oxygen is required by all aerobically respiring plants and animals and it is replenished in daylight by photosynthesizing plants and algae. Under eutrophic conditions, dissolved oxygen greatly increases during the day, but is greatly reduced after dark by the respiring algae and by microorganisms that feed on the increasing mass of dead algae. When dissolved oxygen levels decline to hypoxic levels, fish and other marine animals suffocate. As a result, creatures such as fish, shrimp, and especially immobile bottom dwellers die off.
Zones where this occurs are known as dead zones. Eutrophication may cause competitive release by making abundant a normally limiting nutrient.
This process causes shifts in the species composition of ecosystems. For instance, an increase in nitrogen might allow new, competitive species to invade and out-compete original inhabitant species. This has been shown to occur  in New England salt marshes. In Europe and Asia, the common carp frequently lives in naturally Eutrophic or Hypereutrophic areas, and is adapted to living in such conditions.
The eutrophication of areas outside its natural range partially explain the fish's success in colonising these areas after being introduced. Lesson 9 - Tetrapods: Development of Limbs in Vertebrates. Lesson 10 - Amniotes: Definition and Evolutionary Characteristics. Lesson 11 - Primates and Human Origin. Lesson 1 - What is Nutrition? Lesson 2 - Energy-Yielding Nutrients: Lesson 3 - Structure and Function of Carbohydrates. Lesson 4 - Structure and Function of Lipids.
Lesson 7 - Primary Functions of Protein in the Body. Lesson 8 - DNA: Lesson 9 - Minerals in Our Food: Lesson 10 - Vitamins We Need: Lesson 1 - Digestive System I: The Upper Gastrointestinal Tract. Lesson 2 - Digestive System II: The Lower Gastrointestinal Tract.
Lesson 3 - Anatomy and Physiology of the Mouth. Lesson 4 - Anatomy of the Throat and Esophagus. Lesson 6 - What is the Small Intestine? Lesson 7 - Small Intestine: Nutrient Absorption and Role In Digestion. Lesson 8 - Anatomy and Physiology of the Large Intestine. Lesson 1 - Gross Anatomy of the Airway and Lungs: Lesson 3 - Circulatory System I: Types of Circulatory Systems.
Lesson 4 - Circulatory System II: The Human Vascular System. Lesson 6 - Circulatory System IV: Lesson 7 - Circulatory System V: Lesson 9 - Functions of the Lymphatic System.
Lesson 1 - Excretory System. Lesson 2 - Gross Anatomy of the Urinary System. Lesson 3 - The Kidney: Lesson 4 - The Renal Tubule: Lesson 1 - Hormones: Lesson 2 - What Is the Pituitary Gland? Lesson 3 - The Thyroid Gland: Lesson 4 - Pancreas: Lesson 5 - Adrenal Glands: Lesson 6 - Hormones of the Testes and Ovaries: Lesson 1 - Functions of the Nervous System. Lesson 5 - The Cerebral Cortex: Lesson 6 - Homeostasis and Temperature Regulation in Humans.
Lesson 1 - Overview of Animal Reproduction and Development. Lesson 2 - Male Reproductive System: Lesson 3 - Spermatogenesis: Lesson 4 - Female Reproductive System: Lesson 5 - Oogenesis: Lesson 6 - Fertilization and Zygote Formation: Lesson 2 - Ecosystems, Habitats and Ecological Niches. Lesson 6 - Symbiotic Relationships: Lesson 7 - Populations: