Adaptations to Starvation and Lean Tissue Conservation
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Questions and Answers

What type of fatty acids are primarily found in animal fats and tropical oils?

  • Polyunsaturated fatty acids
  • Saturated fatty acids (correct)
  • Monounsaturated fatty acids
  • Trans fatty acids

Which statement about cis and trans double bonds in fatty acids is correct?

  • Cis double bonds have hydrogen atoms facing opposite directions.
  • Cis double bonds are mainly introduced by human manipulation.
  • Trans double bonds are more abundant in nature than cis double bonds.
  • Trans double bonds are generally produced through hydrogenation. (correct)

What characteristic is true for long-chain fatty acids?

  • They solidify at room temperature. (correct)
  • They contain one double bond.
  • They contain less than 8 carbon atoms.
  • They are primarily liquid at room temperature.

Which of the following fatty acids is classified as essential?

<p>Polyunsaturated fatty acids (D)</p> Signup and view all the answers

What is a typical characteristic of short-chain fatty acids?

<p>They are liquid at colder temperatures. (D)</p> Signup and view all the answers

Which dietary component is crucial for replenishing glycogen stores after aerobic activity?

<p>Carbohydrates (D)</p> Signup and view all the answers

What effect does creatine supplementation have on athletic performance?

<p>Enhances certain power activities (A)</p> Signup and view all the answers

What is a potential consequence of using anabolic steroids?

<p>Development of liver tumors (C)</p> Signup and view all the answers

What role does protein intake play in muscle mass accrual?

<p>Relevant only when combined with resistance exercise (C)</p> Signup and view all the answers

Which nutritional supplement has shown negligible advantages for exercise performance?

<p>Energy bars and drinks (A)</p> Signup and view all the answers

What impact does caffeine have on athletic performance?

<p>Acts as a stimulant that may help in some activities (D)</p> Signup and view all the answers

Which of the following statements about DHEA/Andro is true?

<p>It's a weak version of testosterone (A)</p> Signup and view all the answers

What is a primary reason for athletes to consume high carbohydrate meals?

<p>To stimulate insulin release (A)</p> Signup and view all the answers

What type of fat is primarily found in the body and food, consisting of three fatty acids bound to glycerol?

<p>Triglycerides (B)</p> Signup and view all the answers

Which type of adipose tissue is considered beneficial and provides significant estrogen in non-pregnant females?

<p>Subcutaneous adipose tissue (C)</p> Signup and view all the answers

What is the effect of increasing the number of double bonds in fatty acids on their melting point?

<p>Decreases melting point (A)</p> Signup and view all the answers

Which fatty acid is classified as omega-3 and is known for its anti-inflammatory properties?

<p>Linolenic acid (C)</p> Signup and view all the answers

What is the approximate caloric value of fats and oils per gram?

<p>9 kcal/gram (C)</p> Signup and view all the answers

Which type of adipose tissue surrounds internal organs and is often referred to as 'bad' fat?

<p>Visceral adipose tissue (A)</p> Signup and view all the answers

Which of the following factors contributes to an increase in the melting point of fatty acids?

<p>Higher number of carbon atoms (D)</p> Signup and view all the answers

What is the process called that creates trans fatty acids from fats and oils?

<p>Hydrogenation (D)</p> Signup and view all the answers

What is the relationship between muscle mass in children and brain development?

<p>Higher muscle mass is associated with better brain development. (A)</p> Signup and view all the answers

Why is muscle mass considered an important index of nutritional status?

<p>It is the largest component of fat-free mass. (B)</p> Signup and view all the answers

What does the measurement of muscle mass help with in the context of stunting tests?

<p>It plays a fundamental role in assessing nutritional health. (A)</p> Signup and view all the answers

Which method is NOT mentioned as a reliable way to measure muscle mass?

<p>High-intensity exercise testing (C)</p> Signup and view all the answers

What effect does calorie restriction typically have on lifespan?

<p>It increases lifespan. (B)</p> Signup and view all the answers

In calorie restriction studies, what is a typical percentage reduction in caloric intake?

<p>20-40% (A)</p> Signup and view all the answers

Which of the following is NOT a benefit associated with calorie restriction?

<p>Increased susceptibility to diseases. (A)</p> Signup and view all the answers

What is the primary purpose of measuring D3-creatinine enrichment in muscle mass evaluation?

<p>To determine total body creatine pool size. (A)</p> Signup and view all the answers

What is the primary objective of blood doping?

<p>To enhance oxygen carrying capacity of blood (B)</p> Signup and view all the answers

How can endurance athletes commonly store their own blood for performance enhancement?

<p>Through auto transfusion before races (A)</p> Signup and view all the answers

What significant health risk is associated with blood doping in young athletes?

<p>Blood sludging and strokes (A)</p> Signup and view all the answers

What is the role of erythropoietin in the performance-enhancing process?

<p>To stimulate production of red blood cells (B)</p> Signup and view all the answers

What is the main purpose of anabolic drugs in medical settings?

<p>To enhance muscle growth and rehabilitation (D)</p> Signup and view all the answers

What is a common dietary source of triglycerides in the American diet?

<p>Oils and fats (A)</p> Signup and view all the answers

During fasting, what occurs to triglycerides stored in adipose tissue?

<p>They are broken down to release fatty acids (B)</p> Signup and view all the answers

Which of the following statements about lipids is true?

<p>Fats are solid at room temperature, while oils are liquid (C)</p> Signup and view all the answers

What is insulin resistance primarily defined as?

<p>A state requiring higher levels of insulin for normal biological response (A)</p> Signup and view all the answers

Which statement accurately reflects the relationship between obesity and type 2 diabetes (T2D)?

<p>Approximately 25-30% of obese individuals will develop T2D (C)</p> Signup and view all the answers

What was observed concerning the intake of simple sugars in the average US diet?

<p>Simple sugars now contribute a similar amount of calories as saturated fat (A)</p> Signup and view all the answers

What effect does restricting sugar intake have on adolescents with fatty liver disease?

<p>It reduces fatty liver and fat synthesis in the liver (A)</p> Signup and view all the answers

What percentage of obese individuals are typically affected by insulin resistance?

<p>2/3 of obese individuals (C)</p> Signup and view all the answers

What is a common outcome of excessive intake of simple sugars and fructose?

<p>Increased risk of fatty liver and insulin resistance (C)</p> Signup and view all the answers

Which of the following is true about non-insulin resistant (non-IR) obese individuals?

<p>They are often considered healthy despite their obesity (C)</p> Signup and view all the answers

How is the progression of chronic diseases like T2D best understood?

<p>By studying the timing of progression and underlying causes (A)</p> Signup and view all the answers

Flashcards

Saturated Fatty Acid

A fatty acid with no double bonds between carbon atoms. All carbons are saturated with hydrogen atoms.

Unsaturated Fatty Acid

A fatty acid with one or more double bonds between carbon atoms.

Cis Fatty Acid

Fatty acids with double bonds that have hydrogen atoms on the same side of the bond.

Trans Fatty Acid

Fatty acids with double bonds that have hydrogen atoms on opposite sides of the bond.

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Essential Fatty Acid

Fatty acids that cannot be synthesized by the body and must be obtained from the diet.

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Muscle Mass

A measurement of the amount of skeletal muscle in the body.

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D3-Creatine Dilution Method

A technique using a stable isotope tracer (D3-creatine) ingested orally to measure total body skeletal muscle mass. This method involves the uptake of the tracer into the muscle creatine pool, conversion to creatinine, and analysis of the tracer enrichment in urine.

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Stunting

A condition characterized by a decreased rate of growth in children, typically measured by height and weight.

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Calorie Restriction (CR)

The amount of calories consumed by an individual or animal, compared to the amount they would eat if they were free to eat as much as they wanted.

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Healthspan

The length of time an individual or animal remains in a healthy state, free from diseases and age-related decline.

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Lifespan

The total length of time an individual or animal lives.

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Calorie Restriction (CR)

A reduction in caloric intake without malnutrition, typically 20-40% below the amount that would be consumed ad-libitum.

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Calorie Restriction and Longevity

The ability of calorie restriction to extend both lifespan and healthspan in various organisms including worms, flies, rodents, and primates.

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Erythropoietin (EPO)

A naturally occurring hormone that stimulates the production of red blood cells, primarily used to treat anemia, but also used to enhance athletic performance.

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Altitude Training

The process of training at high altitudes, where oxygen is less abundant, to increase the production of red blood cells and improve oxygen carrying capacity.

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Autologous Blood Transfusion

The storage and re-infusion of an athlete's own blood before a competition to boost red blood cell count and increase oxygen carrying capacity.

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Fat

A type of lipid, specifically triglycerides, that are solid at room temperature. Found in both food and the body.

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Oil

A type of lipid, specifically triglycerides, that are liquid at room temperature. Found in both food and the body.

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Fasting (Lipid Metabolism)

The process of breaking down stored triglycerides in adipose tissue to release fatty acids as an energy source during periods of fasting or low energy intake.

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Feasting (Lipid Metabolism)

The state where excess energy intake is stored as triglycerides in adipose tissue.

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Growth Hormone

A naturally occurring hormone primarily used to treat a variety of conditions like anemia and frailty, but can also be used to enhance athletic performance.

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Insulin Resistance

A state where cells, tissues, or the whole body require higher than normal insulin levels to achieve a normal response.

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Type 2 Diabetes (T2D)

A condition where blood sugar levels are elevated due to the body's inability to use insulin effectively.

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Natural History of Disease

The natural progression of a disease over time, including its stages and potential outcomes.

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Pathogenesis

The study of the mechanisms and processes involved in the development and progression of a disease.

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Metabolic Syndrome

A complex metabolic disorder characterized by insulin resistance, high blood pressure, abdominal obesity, and abnormal lipid levels.

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De Novo Lipogenesis (DNL)

The process of converting excess carbohydrates, particularly fructose, into fat in the liver.

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Fatty Liver Disease

A condition characterized by excessive fat accumulation in the liver, often linked to insulin resistance and obesity.

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Simple Sugars

A simplified sugar, often found in processed foods and drinks, that can contribute to insulin resistance and metabolic problems.

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Oxygen delivery during exercise

The process by which the body delivers more oxygen to exercising muscles. This involves increasing cardiac output, enhancing oxygen-carrying capacity of the blood, and improving capillary density in muscles.

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Muscle oxygen utilization

The ability of exercising muscles to use oxygen efficiently. This is linked to the function of mitochondria, the powerhouses of cells.

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Carbohydrate depletion in athletes

Intense physical activity depletes glycogen stores in muscles and liver. This leads to a craving for carbohydrates to replenish these stores.

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Carbohydrate loading

A strategy where athletes consume high amounts of carbohydrates to maximize glycogen stores before a long endurance event like a marathon. The effectiveness of this technique is debated.

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Protein intake for muscle growth

Increased protein intake is essential for muscle growth when combined with resistance exercise. However, consuming high protein without exercise doesn't significantly impact muscle mass.

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Creatine supplementation

A dietary supplement that may improve power activities like sprinting and weightlifting. It is believed to increase muscle phosphocreatine stores, enhancing energy production.

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Androgenic/Anabolic steroids

Synthetic hormones that mimic the effects of testosterone, leading to increased muscle mass and strength when used in combination with resistance training.

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Consequences of performance-enhancing drugs

Performance-enhancing drugs can have serious side effects, including cardiovascular problems, mood swings, acne, liver damage, and hormonal imbalances.

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Triglyceride (TG/TAG)

A type of fat molecule that includes three fatty acids attached to a glycerol molecule. It is the primary form of fat found in foods and stored in the body.

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Essential Fatty Acids (EFA)

Essential fatty acids (EFA) are fatty acids that cannot be synthesized by the body and must be obtained through diet. They are crucial for the biological processes including growth, skin health, fertility, and cell membrane structure.

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Omega-6 Fatty Acid

A fatty acid with its last double bond located within the terminal six carbon atoms. Examples include linoleic acid (omega 6).

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Omega-3 Fatty Acid

A fatty acid with its last double bond located within the terminal three carbon atoms. Examples include linolenic acid (omega 3).

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Hydrogenation of Fats

The process of adding hydrogen atoms to unsaturated fats, which increases the saturation and changes the configuration of double bonds to 'trans' (as opposed to the naturally occurring 'cis' configuration).

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White Adipose Tissue (WAT)

Fat that is stored in adipose tissue primarily for the purpose of providing energy through fatty acid oxidation. It can be found in subcutaneous and visceral locations.

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Brown Adipose Tissue (BAT)

A specialized type of fat tissue that plays a crucial role in regulating body temperature. It is found in higher concentrations in infants and can be activated in adults.

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Study Notes

Adaptations to Starvation

  • The body is mostly water (60-70% in children, 50% in adults).
  • Lean tissue is about 20% protein.
  • Energy stores are primarily triglycerides in adipose tissue.
  • Total energy content of fat in the body is roughly 135,000 kcal in a 70 kg individual.
  • Key storage sites for carbohydrates include liver (~300 kcal) and muscle (<1200kcal).

Lean Tissue Conservation

  • Normal protein loss equals protein intake (nitrogen balance).
  • Up to ~500 grams of lean tissue can be lost per 100 grams of protein lost.
  • 30 days of a 100 gram protein loss rate could lead to a 3 kg loss.

Starvation and Lethal Losses

  • 40-50% lean body mass loss is lethal.
  • Losing 15kg of lean body mass is life-threatening.
  • Survival can be extended to 60-90 days or more with hydration and electrolyte maintenance

Sequential Metabolic Response

  • Phase 1: Glycogen depletion, high nitrogen loss, baseline fuel maintained
  • Phase 2: Fatty acid oxidation and ketosis, reduced nitrogen loss, tissue loss (~7 days)
  • Phase 3: Brain adapts to ketones, reduced nitrogen and tissue loss, other adaptations occur. This involves the brain shifting from glucose to ketones as its primary fuel source.

Role of Different Tissues in Starvation

  • Liver: reduces glucose release, increases fatty acid oxidation, and decreases gluconeogenesis.
  • Pancreas: reduces insulin secretion.
  • Adipose tissue: increases fatty acid release.
  • Muscle: reduces glucose oxidation, increases fat oxidation, reduces protein breakdown.
  • Brain: adapts to utilize ketones, reduces glucose oxidation, and dramatically reduces amino acid use.

Other Relevant Information

  • The text discusses the hormonal consequences of starvation, reasons for losing nitrogen, interactions of starvation and infection, and effects of feeding during infection.
  • There are also descriptions of stunting, muscle mass as a marker of stunting, and calorie restriction. The text discusses the difference between starvation in mice versus humans, and the importance of understanding the natural history of nutrition-related chronic diseases, particularly type 2 diabetes.
  • The role of fructose in the diet, and the effects of long-term fructose intake on metabolic risks factors.
  • The text thoroughly analyzes the complex relationship between metabolic factors, including those related to insulin, and how they manifest themselves in different conditions.

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Unit 2 Nutrition Notes PDF

Description

This quiz explores the physiological adaptations of the body during starvation, focusing on lean tissue conservation, metabolic responses, and the critical thresholds of body mass loss. Understand the intricate balance of energy stores and the implications of protein loss on survival during prolonged fasting. Test your knowledge on how the body copes with nutrient deficiencies over time.

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