Weight Management
Body weight includes the sum of bone, muscle, organs, body fluids and adipose tissue (tissue made up of mostly fat cells). Due to growth, reproductive status, different levels of physical activity, and the effects of aging, body weight over time is subject to normal changes. Body weight is often described in terms of its composition, of which a two-compartment model is used. This model divides the body into fat mass, which is the fat from all body sources and fat free mass (FFM), this includes water, protein, and mineral components. Please note that FFM is not exactly the same as lean body mass (LBM). LBM is muscle and is usually higher in men than women, increases with exercise, and is lower in older adults.
Body fat
Your total body fat is the combination of essential and storage fats and is expressed as a percentage of your total body weight.
Essential fat is necessary for normal body functioning and is stored in small amounts in the bone marrow, heart, lung, liver, spleen, kidneys, muscles, and nervous system. Essential fat is higher in women (12% of body fat) because it includes fat in the breasts, pelvic regions (hips) and thighs that supports the reproductive process. In men essential fat is approximately 3% of body fat.
Storage fat on the other hand is the energy reserve and is mostly triglycerides in adipose tissue. This fat collects under the skin and around internal organs to protect them from trauma. In an average person, total body fat (essential and storage fat) as a percentage of body weight is between 18% to 24% for men and 25% to 31% for women. Extreme, elite fit men are as low as 2% to 5% body fat whilst women are between 10% to 13% (Digate Muth, 2014).
Body weight includes the sum of bone, muscle, organs, body fluids and adipose tissue (tissue made up of mostly fat cells). Due to growth, reproductive status, different levels of physical activity, and the effects of aging, body weight over time is subject to normal changes. Body weight is often described in terms of its composition, of which a two-compartment model is used. This model divides the body into fat mass, which is the fat from all body sources and fat free mass (FFM), this includes water, protein, and mineral components. Please note that FFM is not exactly the same as lean body mass (LBM). LBM is muscle and is usually higher in men than women, increases with exercise, and is lower in older adults.
Body fat
Your total body fat is the combination of essential and storage fats and is expressed as a percentage of your total body weight.
Essential fat is necessary for normal body functioning and is stored in small amounts in the bone marrow, heart, lung, liver, spleen, kidneys, muscles, and nervous system. Essential fat is higher in women (12% of body fat) because it includes fat in the breasts, pelvic regions (hips) and thighs that supports the reproductive process. In men essential fat is approximately 3% of body fat.
Storage fat on the other hand is the energy reserve and is mostly triglycerides in adipose tissue. This fat collects under the skin and around internal organs to protect them from trauma. In an average person, total body fat (essential and storage fat) as a percentage of body weight is between 18% to 24% for men and 25% to 31% for women. Extreme, elite fit men are as low as 2% to 5% body fat whilst women are between 10% to 13% (Digate Muth, 2014).
Resting Metabolic Rate
Resting metabolic rate (RMR) is the amount of energy your body uses at rest, while your basal metabolic rate (BMR) is the minimum amount of energy used to sustain life. RMR accounts for 60% to 70% of total energy expenditure, and this lessens with age or restriction of energy intake. When you suddenly deprive your body of enough energy whether deliberately or involuntary starvation, the body conserves energy by dropping its RMR as fast as 15% in just 2 weeks. This makes it harder to lose the weight when you start eating adequately again. Overweight occurs when there is an imbalance between the food you eat and the amount of physical activity you engage in. Obesity, however, is a complex issue as it is related to lifestyle, the environment, and genes. Due to this fact, one cannot use a single theory to completely explain why persons become obese, or why is it so difficult for reduced-obese persons to maintain weight loss.
Under normal circumstances, physical activity accounts for 15% to 30% of total energy output, but we must remember that all activity counts. There is a term for this, which is referred to as nonexercised activity thermogenesis (NEAT), whereas the energy expended in voluntary activity is referred to as activity thermogenesis (AT). NEAT accounts for all activity that is not sleeping, eating or sports-like exercise. It includes going to work, typing, doing yard work, toe-tapping and even fidgeting. To help reverse obesity some individuals’ strategies should promote standing and walking for 2.5 hours per day. Many organizations are now looking into wellness approaches that encourage more standing while working, taking the stairs instead of the elevator is another good way to burn energy.
Set Point Theory
The Centre for Health Promotion and Wellness at MIT Medical has it that according to the set-point theory, there is a control system built into every person dictating how much fat he or she should carry, which is a kind of thermostat for body fat. Some persons have a high setting, while others have a low one. Based on this theory, body fat percentage and body weight are matters of internal controls that are set differently in different people.
On a whole the set point is the weight range in which your body is programmed to function at its best. Fat storage in persons that are not obese appears to be regulated in a manner that preserves a specific body weight, as a result deliberate efforts to starve or overfeed are followed by a rapid return to the original body weight – the set point. It is no wonder many persons have a challenge in maintaining their weight loss over time. Emerging evidence from the bariatric surgery experience suggests that this drastic approach to weight loss may result in a new set point by altering anatomy and physiology (Farias 2011). More research is needed to truly establish that there is a set point for weight.
Genetics
Genetics and heredity determine many hormonal and neural factors involved in weight regulation. These include short-term or long-term signals that determine satiety and feeding activity. Small defects in how these mechanisms work or interact could contribute a great deal to weight gain.
The Centers for Disease Control and prevention (CDC) states that in recent decades, obesity has reached epidemic proportions in populations whose environments promote physical inactivity and increased consumption of high-calorie foods. However, not all people living in such environments will become obese, nor will all obese people have the same body fat distribution or suffer the same health problems. These differences can be seen in groups of people with the same racial or ethnic background and even within families. Genetic changes in human populations occur too slowly to be responsible for the obesity epidemic. Nevertheless, the variation in how people respond to the same environment suggests that genes do play a role in the development of obesity.
Sleep and Stress
When sleep is shortened it alters the endocrine regulation of hunger, as a result the hormones that affect appetite take over and may promote excessive energy intake. Thus, if one continues to be deprived of sleep it can lead to the modification of the amount, composition and distribution of food intake and may contribute to the obesity epidemic.
Stress is another factor that affects weight gain. The hormone cortisol is released when a person is under stress, which stimulates insulin release to maintain glucose levels in the fight-or-flight response, thus appetite increase occurs. Overtime this increase in appetite will lead to excessive weight gain.
Management of Obesity
Balancing energy intake and energy output is the basis for weight management throughout life. For you to effect long term change, lifestyle modification and becoming aware of eating behaviours to manage them better is crucial. It is recommended that one tries to prevent gradual weight gain over time by making small reductions in overall calorie intake and increasing physical activity.
The goal of obesity treatment should therefore focus on weight management and attaining the best weight possible in the context of overall health. It is not always realistic to achieve an ideal body weight or body fat percentage because this depends on the type and severity of the obesity and the age and lifestyle of the individual. As such, to achieve success in reducing body weight varies from being relatively simple to being virtually impossible. One must also bear in mind what is their goal in achieving weight loss as it is not always the same for everyone. Indeed, behaviour modification is the corner stone of lifestyle intervention as it focusses on restructuring a person’s environment, nutrient intake and physical activity level.
Physical activity as a component is very important for weight loss/maintenance interventions as this helps to increase energy expenditure. It also strengthens your cardiovascular integrity and increases sensitivity to insulin, which overall delay or prevent the onset of chronic diseases such as diabetes, high blood pressure, heart disease etc.
The CDC states that physical activity is anything that gets your body moving. According to the 2008 Physical Activity Guidelines for Americans, you need to do two types of physical activity each week to improve your health–aerobic and muscle-strengthening.
CDC advises that children and adolescents should do 60 minutes (1 hour) or more of physical activity each day.
Adults need 2 hours and 30 minutes (150 minutes) of moderate intensity aerobic activities (brisk walk), or 1 hour and 15 minutes (75 minutes) of vigorous-intensity aerobic activity (i.e., jogging or running) every week, and muscle-strengthening-activities on 2 or more days a week that work all major muscle groups (legs, hips, back, abdomen, chest, shoulders, and arms).
References
Krause’s Food & The Nutrition Care Process
By L. Kathleen Mahan, Janice L Raymond
https://medical.mit.edu/sites/default/files/set_point_theory.pdf
https://www.cdc.gov/genomics/resources/diseases/obesity/
https://www.cdc.gov/physicalactivity/basics/adults/index.htm
Resting metabolic rate (RMR) is the amount of energy your body uses at rest, while your basal metabolic rate (BMR) is the minimum amount of energy used to sustain life. RMR accounts for 60% to 70% of total energy expenditure, and this lessens with age or restriction of energy intake. When you suddenly deprive your body of enough energy whether deliberately or involuntary starvation, the body conserves energy by dropping its RMR as fast as 15% in just 2 weeks. This makes it harder to lose the weight when you start eating adequately again. Overweight occurs when there is an imbalance between the food you eat and the amount of physical activity you engage in. Obesity, however, is a complex issue as it is related to lifestyle, the environment, and genes. Due to this fact, one cannot use a single theory to completely explain why persons become obese, or why is it so difficult for reduced-obese persons to maintain weight loss.
Under normal circumstances, physical activity accounts for 15% to 30% of total energy output, but we must remember that all activity counts. There is a term for this, which is referred to as nonexercised activity thermogenesis (NEAT), whereas the energy expended in voluntary activity is referred to as activity thermogenesis (AT). NEAT accounts for all activity that is not sleeping, eating or sports-like exercise. It includes going to work, typing, doing yard work, toe-tapping and even fidgeting. To help reverse obesity some individuals’ strategies should promote standing and walking for 2.5 hours per day. Many organizations are now looking into wellness approaches that encourage more standing while working, taking the stairs instead of the elevator is another good way to burn energy.
Set Point Theory
The Centre for Health Promotion and Wellness at MIT Medical has it that according to the set-point theory, there is a control system built into every person dictating how much fat he or she should carry, which is a kind of thermostat for body fat. Some persons have a high setting, while others have a low one. Based on this theory, body fat percentage and body weight are matters of internal controls that are set differently in different people.
On a whole the set point is the weight range in which your body is programmed to function at its best. Fat storage in persons that are not obese appears to be regulated in a manner that preserves a specific body weight, as a result deliberate efforts to starve or overfeed are followed by a rapid return to the original body weight – the set point. It is no wonder many persons have a challenge in maintaining their weight loss over time. Emerging evidence from the bariatric surgery experience suggests that this drastic approach to weight loss may result in a new set point by altering anatomy and physiology (Farias 2011). More research is needed to truly establish that there is a set point for weight.
Genetics
Genetics and heredity determine many hormonal and neural factors involved in weight regulation. These include short-term or long-term signals that determine satiety and feeding activity. Small defects in how these mechanisms work or interact could contribute a great deal to weight gain.
The Centers for Disease Control and prevention (CDC) states that in recent decades, obesity has reached epidemic proportions in populations whose environments promote physical inactivity and increased consumption of high-calorie foods. However, not all people living in such environments will become obese, nor will all obese people have the same body fat distribution or suffer the same health problems. These differences can be seen in groups of people with the same racial or ethnic background and even within families. Genetic changes in human populations occur too slowly to be responsible for the obesity epidemic. Nevertheless, the variation in how people respond to the same environment suggests that genes do play a role in the development of obesity.
Sleep and Stress
When sleep is shortened it alters the endocrine regulation of hunger, as a result the hormones that affect appetite take over and may promote excessive energy intake. Thus, if one continues to be deprived of sleep it can lead to the modification of the amount, composition and distribution of food intake and may contribute to the obesity epidemic.
Stress is another factor that affects weight gain. The hormone cortisol is released when a person is under stress, which stimulates insulin release to maintain glucose levels in the fight-or-flight response, thus appetite increase occurs. Overtime this increase in appetite will lead to excessive weight gain.
Management of Obesity
Balancing energy intake and energy output is the basis for weight management throughout life. For you to effect long term change, lifestyle modification and becoming aware of eating behaviours to manage them better is crucial. It is recommended that one tries to prevent gradual weight gain over time by making small reductions in overall calorie intake and increasing physical activity.
The goal of obesity treatment should therefore focus on weight management and attaining the best weight possible in the context of overall health. It is not always realistic to achieve an ideal body weight or body fat percentage because this depends on the type and severity of the obesity and the age and lifestyle of the individual. As such, to achieve success in reducing body weight varies from being relatively simple to being virtually impossible. One must also bear in mind what is their goal in achieving weight loss as it is not always the same for everyone. Indeed, behaviour modification is the corner stone of lifestyle intervention as it focusses on restructuring a person’s environment, nutrient intake and physical activity level.
Physical activity as a component is very important for weight loss/maintenance interventions as this helps to increase energy expenditure. It also strengthens your cardiovascular integrity and increases sensitivity to insulin, which overall delay or prevent the onset of chronic diseases such as diabetes, high blood pressure, heart disease etc.
The CDC states that physical activity is anything that gets your body moving. According to the 2008 Physical Activity Guidelines for Americans, you need to do two types of physical activity each week to improve your health–aerobic and muscle-strengthening.
CDC advises that children and adolescents should do 60 minutes (1 hour) or more of physical activity each day.
Adults need 2 hours and 30 minutes (150 minutes) of moderate intensity aerobic activities (brisk walk), or 1 hour and 15 minutes (75 minutes) of vigorous-intensity aerobic activity (i.e., jogging or running) every week, and muscle-strengthening-activities on 2 or more days a week that work all major muscle groups (legs, hips, back, abdomen, chest, shoulders, and arms).
References
Krause’s Food & The Nutrition Care Process
By L. Kathleen Mahan, Janice L Raymond
https://medical.mit.edu/sites/default/files/set_point_theory.pdf
https://www.cdc.gov/genomics/resources/diseases/obesity/
https://www.cdc.gov/physicalactivity/basics/adults/index.htm