chapter 9 human nut

Question 1

What are the main energy systems that enable muscle cells to regenerate ATP during physical activity?

Answer 1

The phosphagen system (creatine phosphate system), the lactic acid system (anaerobic glycolysis), and the aerobic system (aerobic glycolysis, fatty acid oxidation, and TCA cycle).

Question 2

How does the phosphagen system contribute to energy production during physical activity, and how long does it last?

Answer 2

The phosphagen system involves the breakdown of creatine phosphate (CP) anaerobically, providing phosphate to replenish ATP. It lasts for about 10 seconds, providing quick energy for activities like a 100-meter dash.

Question 3

Describe the lactic acid system and its role in energy production during physical activity.

Answer 3

After the initial 10 seconds of intense activity, the lactic acid system involves the anaerobic breakdown of glucose to pyruvate and then to lactate. It generates a small amount of ATP quickly, suitable for high-intensity activity lasting up to 3 minutes.

Question 4

What is the aerobic system, and how does it support prolonged, sustained physical activity?

Answer 4

continuously oxidizes carbohydrates, fats, and some amino acids to provide ATP for muscle contraction. It supports prolonged, sustained activity by ensuring an uninterrupted supply of ATP. The fuel mixture used during physical activity depends on diet, intensity, duration, and conditioning.

Question 5

Explain the role of glucose in physical activity, including its storage form and impact on performance.

Answer 5

Glucose, stored as glycogen in the liver and muscles, is vital for physical activity. It is broken down to provide energy during exertion. Athletes with well-filled glycogen stores can perform better, and diet influences glycogen storage.

Question 6

How does intensity and duration of activity affect glycogen use, and what happens when glycogen stores are depleted?

Answer 6

Intense activities use glycogen quickly, while moderate activities conserve glycogen by relying partly on fatty acids. When glycogen stores are depleted, muscles become fatigued, and physical activity becomes difficult.

Question 7

Examine the impact of training on glycogen use and muscle adaptation.

Answer 7

Training affects glycogen use by conditioning muscles to store more glycogen and rely less on glucose for energy. Trained muscles also use oxygen more efficiently due to increased mitochondria, allowing for slower glycogen breakdown.

Question 8

Describe the role of glucose before, during, and after physical activity.

Answer 8

Before activity, glucose from carbohydrate-rich meals tops off glycogen stores. During activity, glucose can be obtained from glycogen stores and consumed foods. After activity, consuming high-carbohydrate foods accelerates glycogen storage.

Question 9

What is the role of protein in physical activity, both in muscle building and as a fuel source?

Answer 9

Protein is crucial for muscle building, with synthesis accelerating during recovery. During activity, muscles use amino acids for energy, but protein contributes only about 10% of total fuel used.

Question 10

Discuss dietary recommendations for protein intake for athletes based on various factors.

Answer 10

Athletes need more protein than sedentary individuals, but excessive protein intake is not recommended. Protein needs depend on factors such as training, frequency, intensity, and energy availability.

Question 11

Explain the relationship between vitamins, minerals, and physical activity.

Answer 11

Vitamins and minerals assist in releasing energy and transporting oxygen during physical activity. While nutrient supplements may not enhance performance in well-nourished individuals, deficiencies can impede performance.

Question 12

What is the recommended approach for athletes to meet their vitamin and mineral needs through diet?

Answer 12

Well-nourished athletes can meet their vitamin and mineral needs by consuming nutrient-dense foods that match their increased energy needs. Supplements may be beneficial for those with deficiencies or difficulty maintaining a healthy body weight.

Question 13

Why are vitamin or mineral supplements taken right before an event considered ineffective for improving performance?

Answer 13

Most vitamins and minerals function as parts of larger working units, requiring hours or days to assemble with other components after absorption. Taking supplements right before an event is generally ineffective for immediate performance improvement.

Question 14

What is the prevalence of overweight and obesity in the United States?

Answer 14

n estimated 70 percent of adults in the United States are considered overweight or obese, defined by a BMI of 25 to 29.9 or 30 and greater, respectively.

Question 15

How has the prevalence of obesity changed over the past five decades?

Answer 15

Over the past five decades, obesity has increased in every state, in both genders, and across all ages, races, and educational levels.

Question 16

What are the key factors contributing to the development of obesity in individuals?

Answer 16

The key factors contributing to the development of obesity include genetics, environment, cultural, behavioral, socioeconomic, psychological, and metabolic factors. These factors are often interrelated.

Question 17

Explain the process of fat cell development and its role in obesity.

Answer 17

Fat cell development involves an increase in both the number and size of fat cells. Obesity occurs when a person’s fat cells increase in number, size, or both. Prevention of obesity is crucial during childhood and adolescence when fat cells increase in number.

Question 18

What is the role of leptin in the regulation of appetite and body weight?

Answer 18

Leptin is a hormone that regulates food intake and energy expenditure in response to adipose tissue. When body fat increases, leptin increases, suppressing appetite. When body fat decreases, leptin decreases, stimulating appetite and suppressing energy expenditure.

Question 19

How do ghrelin levels influence appetite and food intake?

Answer 19

Ghrelin is a hormone that stimulates appetite and triggers the desire to eat. Ghrelin levels rise before a meal and decline afterward. Higher ghrelin levels are associated with increased hunger, especially during low-calorie diets.

Question 20

What are some environmental factors contributing to obesity?

Answer 20

The obesogenic environment includes factors such as decreased physical activity, increased availability of high-calorie foods, large portion sizes, and sedentary activities like watching TV and using computers.

Question 21

How does physical inactivity contribute to weight gain and obesity?

Answer 21

Physical inactivity contributes to weight gain by requiring little energy expenditure beyond the resting metabolic rate, replacing time spent in more vigorous activities, and influencing food purchases and snacking on high-calorie foods.

Question 22

Why is the concept of set-point theory important in understanding weight regulation?

Answer 22

Set-point theory suggests that the body adjusts its metabolism to favor weight regain after weight loss. This adaptation may explain the difficulty in maintaining weight loss and the decrease in metabolic rate after weight loss.

Question 23

What are some health risks associated with obesity?

Answer 23

Health risks associated with obesity include heart disease, type 2 diabetes, and all-cause mortality. Higher BMI and waist circumference increase the risk of these health problems.

Question 24

How do social consequences contribute to the challenges faced by obese individuals?

Answer 24

Obese individuals may face prejudice and discrimination, affecting job opportunities, social interactions, and self-esteem. Socially, they may be negatively stereotyped as lazy, leading to increased risk of overeating and obesity.

Question 25

What are some dangers associated with weight-loss interventions?

Answer 25

Some weight-loss interventions, such as fad diets and unsafe supplements, can lead to adverse reactions and pose physical, metabolic, and psychosocial risks. It is essential to scrutinize such interventions and consult with healthcare professionals.

Question 26

Why is the energy-balance equation considering time important in understanding obesity?

Answer 26

The energy-balance equation must consider time, as both present and past eating and activity patterns influence current body weight. Factors like the demand for physical activity and large portion sizes over time contribute to the rise in obesity rates.

Question 27

What are some psychological problems associated with obesity?

Answer 27

Obese individuals may suffer embarrassment, shame, and depression due to hostility and contempt from others. Anxiety and depression can contribute to the development of obesity, creating a cycle of psychological burden.

Question 28

How do social relationships influence food choices and the development of obesity?

Answer 28

Social relationships, including friends, siblings, or spouses, can influence food choices and increase the likelihood of obesity when a close connection becomes obese. Social factors play a role in the complex interplay of genetics and the environment in obesit

Question 29

What are the primary strategies for weight loss, and how do they vary based on the degree of obesity?

Answer 29

e primary strategies for weight loss vary based on the degree of obesity. An overweight person may improve eating habits and increase physical activity, while someone with clinically severe obesity may need more aggressive options like drugs or surgery.

Question 30

How do weight-loss drugs work, and what are the challenges associated with their long-term use?

Answer 30

Weight-loss drugs aim to help with meaningful weight loss as part of a comprehensive program. Long-term use is challenging due to potential risks, and the balance between maintaining excess weight and taking drugs for an extended period is a consideration. Prescribing should be done cautiously, and benefits must exceed risks.

Question 31

Under what conditions is bariatric surgery considered as an option for weight loss?

Answer 31

Bariatric surgery is considered for individuals unable to achieve adequate weight loss through diet and exercise, with a BMI of 40 or BMI of 35 with obesity-related health problems, no medical or psychological contraindications, and a strong motivation to comply with post-surgery treatment plans.

Question 32

What are the advantages and potential risks associated with bariatric surgery for weight loss?

Answer 32

Bariatric surgery provides significant advantages for greater weight loss and long-term survival. Most people experience improvements in diabetes, blood lipids, blood pressure, and overall cardiovascular risks. However, risks include vitamin and mineral deficiencies, the need for lifelong medical supervision, and the possibility of weight regain and psychological issues.

Question 33

What is “off-label” use of weight-loss drugs, and what precautions should be taken when using such drugs?

Answer 33

Off-label use involves prescribing drugs approved for other conditions for weight loss. Physicians must be well-informed about these drugs’ use, effects, and closely monitor patients’ responses due to potential risks.

Question 34

What are the recent medical procedures approved for weight loss, and how do they compare with drugs and surgery?

Answer 34

Endoscopic procedures like intragastric balloon insertion or gastric aspiration are less invasive alternatives to drugs and surgery. They are effective, less expensive, and easily reversible compared to other methods.

Question 35

hat factors contribute to obesity, and what integrated approaches are recommended for successful treatment?

Answer 35

ctors contributing to obesity are numerous and complex. Integrated approaches include healthy eating patterns, physical activities, supportive environments, and psychosocial support.

Question 36

What is a reasonable rate of weight loss for overweight adults, and why are gradual losses more likely to be maintained?

Answer 36

A reasonable rate of weight loss is 1 to 2 pounds per week or 5 to 10 percent of body weight over six months. Gradual losses are more likely to be maintained because they are associated with lifestyle changes that individuals can incorporate into their daily lives.

Question 37

What should be the main characteristic of a weight-loss diet, and why is energy intake restriction a concern?

Answer 37

The main characteristic of a weight-loss diet is providing less energy than needed to maintain present body weight. Restricting energy intake too severely can lead to nutrient deficiencies, excessive loss of lean tissue, lower basal metabolic rate, and rapid weight regain.

Question 38

How can individuals achieve nutritional adequacy while on a low-calorie diet, and why is emphasis on nutritional adequacy important?

Answer 38

Achieving nutritional adequacy on a low-calorie diet involves careful selection of nutrient-dense foods. Emphasizing nutritional adequacy is crucial to support healthier and more successful weight loss and to prevent feelings of starvation and deprivation.

Question 39

What are some practical tips for managing portion sizes and promoting satiety during meals?

Answer 39

Practical tips include eating small portions, slowing down while eating, and emphasizing nutritional adequacy. The concept of “hara hachi bu,” or eating until 80 percent full, is highlighted as a strategy.

Question 40

Why is physical activity considered an essential component of weight management, and what are the recommended activity levels?

Answer 40

Physical activity is essential for weight management, with recommendations of 200 to 300 minutes of moderately intense physical activity per week. Combining diet and exercise leads to better fat loss, muscle retention, and improved overall health.

Question 41

ow does activity contribute to energy expenditure in an indirect way?

Answer 41

Activity contributes to energy expenditure indirectly by speeding up metabolism for hours or even days, known as the postexercise effect. This effect can raise the energy expenditure of exercise by up to 15 percent.

Question 42

What long-term effects does daily vigorous activity have on body composition?

Answer 42

Daily vigorous activity gradually leads to the development of more lean tissue. This increase in lean tissue results in a rise in metabolic rate, supporting continued weight loss or maintenance.

Question 43

How does physical activity impact body fat and lean body mass, even without weight loss?

Answer 43

Physical activity changes body composition by reducing body fat and increasing lean body mass. Even without weight loss, physically active individuals have less body fat than sedentary individuals with the same BMI.

Question 44

What is the relationship between activity and appetite control?

Answer 44

Contrary to the belief that being active increases hunger, research shows that exercise does not cause overeating. In fact, appetite is suppressed after exercise. The body releases fuels to support exercise, and appetite is usually calmed down after energy fuels are stored back.

Question 45

How does activity contribute to stress reduction and psychological benefits?

Answer 45

Physical activity helps reduce stress, which is particularly beneficial for individuals who respond to stress with inappropriate eating. Additionally, activity improves body image, separates the connections between body weight and self-worth, and enhances self-esteem, creating a

Question 46

What advice is given regarding the choice and schedule of physical activity?

Answer 46

People should choose activities they enjoy and can do regularly. The schedule of physical activity is flexible; both several short bouts of exercise or one continuous workout are beneficial. Any activity is better than being sedentary.

Question 47

How can distractions influence food intake, and what is the suggested approach?

Answer 47

Distractions can initiate eating, interfere with internal controls to stop eating, and extend the duration of eating. To control portion sizes, extra care is needed when distractions are present during meals. People should be mindful of their eating habits when distracted.

Question 48

What cognitive skills are essential for successful behavior changes in weight management?

Answer 48

Two cognitive skills, problem solving, and cognitive restructuring, are crucial. Problem-solving helps identify and implement solutions, while cognitive restructuring replaces negative thoughts with positive ones, supporting behavior change.

Question 49

What are some common strategies used by individuals in the National Weight Control Registry who have successfully maintained weight loss?

Answer 49

Strategies include eating a low-calorie diet, high nutrient-density, and low energy-density foods; engaging in regular physical activity; monitoring weight frequently; using problem-solving skills and positive self-talk; limiting television time; and seeking support from registered dietitians, physicians, or support groups.

Question 50

What role does physical activity play in preventing weight gains and maintaining weight losses?

Answer 50

Physical activity plays a key role in preventing weight gains and maintaining weight losses. Those who consistently exercise are more successful, and weight maintenance may require expending at least 2500 kcalories in physical activity per week.

Question 51

What are some strategies for preventing weight gain, and how do they differ from weight loss strategies?

Answer 51

Strategies include eating regular meals, drinking water instead of high-calorie beverages, selecting sensible portion sizes, being physically active, and limiting sedentary activities. The key difference is that these strategies begin early, becoming integral parts of a person’s life.

Question 52

What is the significance of community programs in preventing obesity, and what strategies do they involve?

Answer 52

Community programs are crucial for preventing obesity, involving strategies like providing pedestrian-friendly streets, taxing sugar-sweetened beverages, and addressing social networks, community institutions, and government policies.

Question 53

What are the key diet-planning strategies for weight gain, and how can energy-dense foods be incorporated?

Answer 53

Key strategies for weight gain include consuming energy-dense foods and building muscle through strength training. Energy-dense foods, which were eliminated in weight-loss diets, can be selected from each food group to provide more kcalories in a small volume.

Question 54

How can underweight individuals increase energy intake through beverages?

Answer 54

Beverages provide an easy way to increase energy intake. For instance, consuming juice or milk can add significant kcalories. Liquid dietary supplements are also recommended for those underweight due to illness.

Question 55

What are some suggested weight-gain strategies for underweight individuals related to meal size and frequency?

Answer 55

Underweight individuals should prioritize regular meals, eat larger portions, and include extra snacks between meals. Beverages, such as juice and milk, can contribute to increased energy intake. Strength training is recommended for building muscle and supporting weight gain.