Question 1

Inappropriate strategies for weight loss can increase impaired physiologic function and exercise performance.

Accepted Answer

Inappropriate weight loss strategies, such as extreme calorie restriction, improper dieting, or excessive exercise, can lead to nutrient deficiencies, muscle loss, and decreased energy levels, all of which impair physiological function and reduce exercise performance.

Question 2

Overweight refers to the overfat condition that accompanies a constellation of comorbidities.

Accepted Answer

Overweight is generally defined by body mass index (BMI) and does not directly measure overfat condition or account for comorbidities. It is a condition where a person's weight is higher than what is considered as a normal weight adjusted for height.

Question 3

Muscle fiber type, genetics, body size, and previous training experience affect the magnitude of lean tissue synthesis with resistance training in men and women.

Accepted Answer

These factors influence how individuals respond to resistance training, including the rate and extent of muscle growth and strength gains. Genetics can determine muscle fiber type distribution and hormonal responses, body size impacts metabolic rates and energy distribution, and previous training experience affects the efficiency and capacity for adaptation to training stimuli.

Question 4

The 3500-kilocalorie rule grossly overestimates actual weight loss.

Accepted Answer

The 3500-kilocalorie rule, which suggests that a calorie deficit of 3500 kcal leads to a weight loss of one pound, does not account for the dynamic changes in energy balance that occur during weight loss, leading to an overestimation of actual weight loss.

Question 5

The new weight-loss model relies on controlled feeding studies that show a "metabolic slowdown" and loss of weight directly contribute to increased energy expended in physical activity.

Accepted Answer

The new weight-loss model suggests that a "metabolic slowdown" occurs as a result of weight loss, but this does not directly contribute to increased energy expended in physical activity. Instead, metabolic slowdown refers to the body's adaptation to lower energy intake and weight loss by reducing the amount of energy it expends, making further weight loss more difficult.

Question 6

A 25-year epidemiological Swedish study concluded that over time reducing dietary animal fat increased blood cholesterol levels, yet a high-fat, low-carbohydrate diet decreased these levels.

Accepted Answer

The statement is misleading as it conflates different aspects of dietary studies. Most epidemiological studies, including those from Sweden, have shown that replacing saturated fats (commonly found in animal fats) with unsaturated fats or high-quality carbohydrates can lower blood cholesterol levels. A high-fat, low-carbohydrate diet, particularly if it includes a significant amount of unsaturated fats, can improve lipid profiles, but this does not imply that reducing dietary animal fat increases cholesterol levels in general.

Question 7

While low-carbohydrate/high-fat diets may help short-term weight loss, long-term weight loss is not maintained, increasing blood cholesterol with a potential, major impact on cardiovascular disease risk.

Accepted Answer

Low-carbohydrate/high-fat diets can lead to short-term weight loss, but they may increase cholesterol levels, potentially raising cardiovascular disease risk over time.

Question 8

The low body fat levels of marathon runners, ranging from 1% to 8% of body weight, probably reflect an adaptation to long-term training for distance running and a reduced energy intake relative to energy output from intense training.

Accepted Answer

Marathon runners typically have low body fat due to the high energy expenditure from their intense and prolonged training, which often exceeds their energy intake, leading to reduced body fat as an adaptation to their sport.

Question 9

A relatively low body fat increases the energy cost of weight-bearing physical activity and also provides a worsening gradient to dissipate metabolic heat generated during up to 45 minutes of physical activity.

Accepted Answer

A relatively low body fat decreases the energy cost of weight-bearing physical activity and improves the gradient to dissipate metabolic heat, making physical activity more efficient.

Question 10

Researchers maintain that more than 75% of the U.S. adult population may reach overweight or obesity status by the year 2020, with essentially the entire adult population becoming overweight within three generations.

Accepted Answer

The passage states that "Researchers maintain that more than 75% of the U.S. adult population may reach overweight or obesity status by the year 2020".

Question 11

More than 69% of the U.S. population now classify as either overweight or obese with 25% to 30% achieving the overweight classification.

Accepted Answer

The answer of More than 69% of the U.S. population...

Question 12

More likely than not, the culprits in the fattening of America are predominantly a sedentary lifestyle and ready availability of tasty, lipid-rich, and calorie-rich foods currently offered in increasingly larger portions.

Accepted Answer

The obesity epidemic in America is largely attributed to a combination of a sedentary lifestyle and the easy access to high-calorie, high-fat foods that are often served in large portions, contributing significantly to weight gain and obesity.

Question 13

In adults, brown fat spurs the body to burn calories to generate body heat without ATP production via uncoupled metabolism.

Accepted Answer

Brown fat generates heat through a process called non-shivering thermogenesis, where it burns calories without producing ATP, due to the action of a protein called uncoupling protein-1 (UCP1) which uncouples oxidative phosphorylation from ATP production.

Question 14

The elevated thermic effect of dietary protein, with its relatively low coefficient of digestibility particularly for plant protein, reduces the net calories available from ingested protein compared with a well-balanced meal of equivalent caloric value.

Accepted Answer

The thermic effect of food (TEF) is higher for protein than for fats or carbohydrates, meaning that the body uses more energy to digest, absorb, and metabolize protein. Additionally, plant proteins often have a lower digestibility compared to animal proteins, which further reduces the net calories available from protein compared to a balanced meal of equivalent caloric value.

Question 15

Excessive body fatness becomes particularly prevalent among affluent, white children.

Accepted Answer

Excessive body fatness or obesity can affect children from various socio-economic backgrounds, ethnicities, and races. It is not limited to affluent, white children but is a widespread issue influenced by factors such as diet, physical activity, genetics, and socio-economic status.

Question 16

Intense aerobic training should not coincide with resistance training when trying to achieve maximal increases in muscle mass.

Accepted Answer

Intense aerobic training can interfere with muscle hypertrophy by competing for recovery resources and potentially impairing strength adaptations, which are crucial for maximizing muscle mass.

Question 17

Selective physical activity of specific body areas proves more effective for localized fat loss than more general physical activity.

Accepted Answer

Localized fat loss, or "spot reduction," is largely a myth; fat loss tends to be systemic and not specific to the area being exercised. More general physical activity and overall caloric deficit are more effective for reducing body fat.

Question 18

Substantial alterations in the population's gene pool likely explain the dramatic worldwide obesity epidemic.

Accepted Answer

The dramatic worldwide obesity epidemic is more accurately attributed to changes in diet and lifestyle rather than substantial alterations in the population's gene pool, as genetic changes occur over much longer periods.

Question 19

Research indicates no genetic link for susceptibility to obesity.

Accepted Answer

Research has identified multiple genetic factors that can predispose individuals to obesity, indicating a significant genetic component to the condition.

Question 20

Age-trend data indicate that men and women lose weight as they grow older throughout middle age.

Accepted Answer

Age-trend data typically show that both men and women tend to gain weight through middle age due to factors like a decrease in metabolism and physical activity levels.

Quiz 14: Energy Balance, Physical Activity