In this model, the reservoir of body fatness responds to energy intake or energy expenditure, such that if a person is exposed to a greater amount of food, body fatness increases, or if a person watches more television body fatness increases.

A major problem with these theories is that they overgeneralize and do not take into account that not all individuals respond in the same way to changes in food intake or energy expenditure. This brings up the importance of the interactions of genes and the environment.

Not all individuals who take a weight-loss drug lose weight and not all people who smoke are thin. One example is a study of the offspring of women who were overweight during pregnancy had a greater propensity for being overweight and for developing Type 2 diabetes. Thus, undernutrition and overnutrition during pregnancy influence body weight and disease risk for offspring later in life.

They do so by adapting energy metabolism to the early nutrient and hormonal environment in the womb. Sedentary behaviour is defined as the participation in the pursuits in which energy expenditure is no more than one-and-one-half times the amount of energy expended while at rest and include sitting, reclining, or lying down while awake.

Of course, the sedentary lifestyle of many North Americans contributes to their average energy expenditure in daily life. Simply put, the more you sit, the less energy you expend.

A study published in a issue of the American Journal of Epidemiology reports that 55 percent of Americans spend 7. Fortunately, including only a small amount of low-level physical activity benefits weight control.

A study published in the June issue of the International Journal of Behavioral Nutrition and Physical Activity reports that even breaking up sitting-time with frequent but brief increased energy expenditure activities, such as walking for five minutes every hour, helps maintain weight and even aids in weight loss.

North Americans partake in an excessive amount of screen time, which is a sedentary behaviour that not only reduces energy expenditure, but also contributes to weight gain because of the exposure to aggressive advertising campaigns for unhealthy foods. Many societal factors influence the number of calories burned in a day.

Escalators, moving walkways, and elevators not to mention cars! are common modes of transportation that reduce average daily energy expenditure.

Office work, high-stress jobs, and occupations requiring extended working hours are all societal pressures that reduce the time allotted for exercise. Even the remote controls that many have for various electronic devices in their homes contribute to society being less active.

Socioeconomic status has been found to be inversely proportional to weight gain. One reason for this relationship is that inhabitants of low-income neighborhoods have reduced access to safe streets and parks for walking. Another is that fitness clubs are expensive and few are found in lower-income neighborhoods.

Chronic diseases are ongoing, life-threatening, and life-altering health challenges. They are the leading cause of death worldwide and are increasing in frequency. They cause significant physical and emotional suffering and are an impediment to economic growth and vitality.

It is important, now more than ever, to understand the different risk factors for chronic disease and to learn how to prevent their development. A risk factor is an indicator that your chances for acquiring a chronic disease may be increased.

For example, if a person gets sick with the flu, we can say with certainty that the illness was caused by a virus. Whereas, even though the risk factor of a sedentary lifestyle is highly correlated to the development of cardiovascular disease, we cannot say that this risk factor caused cardiovascular disease because there are several other factors that may have contributed to the development of this disease.

Risk factors such as genetics and age cannot be changed. However, some risk factors can be altered to promote health and wellness , such as diet.

For example, a person who continuously eats a diet high in sugars, saturated fats, and red meat is at risk for becoming obese and developing Type 2 diabetes, cardiovascular disease, or several other conditions.

Making more healthy dietary choices can greatly reduce that risk. Being a woman over age sixty-five is a risk factor for developing osteoporosis, but that cannot be changed. Also, people without a genetic predisposition for a particular chronic illness can still develop it. Not having a genetic predisposition for a chronic disease is not a guarantee of immunity.

What diseases do you note showing up among close blood relatives? At your next physical, pay attention to your blood tests and ask the doctor if any results are out of normal range.

It is also helpful to note your vital signs, particularly your blood pressure and resting heart rate. In addition, you may wish to keep a food diary to make a note of the dietary choices that you make on a regular basis and be aware of foods that are high in saturated fat, among other unhealthy options.

As a general rule, it is important to look for risk factors that you can modify to promote your health. For example, if you discover that your grandmother, aunt, and uncle all suffered from high blood pressure, then you may decide to avoid a high sodium diet.

Identifying your risk factors can arm you with the information you need to help ward off disease. html to see the prevalence of self-reported obesity among U. adults from Source: Weight Management. As BMIs increase over 25, health risk increases for heart disease, Type 2 diabetes, hypertension, endometrial cancer, postmenopausal breast cancer, colon cancer, stroke, osteoarthritis, liver disease, gallbladder disorders, and hormonal disorders.

The WHO reports that overweight and obesity are the fifth leading cause for deaths globally , and estimates that more than 2. Similar to other public health organizations, the WHO states the main causes of the obesity epidemic worldwide are the increased intake of energy-dense food and decreased level of physical activity that is mainly associated with modernization, industrialization, and urbanization.

The environmental changes that contribute to the dietary and physical activity patterns of the world today are associated with the lack of policies that address the obesity epidemic in the food and health industry, urban planning, agriculture, and education sectors. Excessive weight gain has become an epidemic.

The more overweight a person is, the greater his or her risk of developing life-threatening complications. There is no single cause of obesity and no single way to treat it.

However, a healthy, nutritious diet is generally the first step, including consuming more fruits and vegetables, whole grains, and lean meats and dairy products and less processed high sugar and fat foods.

Diabetes is one of the top three diseases in North America. It affects millions of people and causes tens of thousands of deaths each year. Diabetes is a metabolic disease of insulin deficiency and glucose over-sufficiency. One sure way to decrease your chances of getting diabetes is to maintain an optimal body weight by adhering to a diet that is balanced in carbohydrate, fat, and protein intake.

There are three different types of diabetes: Type 1 diabetes, Type 2 diabetes, and gestational diabetes. Type 1 diabetes is a metabolic disease in which insulin-secreting cells in the pancreas are killed by an abnormal response of the immune system, causing a lack of insulin in the body.

Its onset typically occurs before the age of thirty. The only way to prevent the deadly symptoms of this disease is to inject insulin under the skin. A person with Type 1 diabetes usually has a rapid onset of symptoms that include hunger, excessive thirst and urination, and rapid weight loss.

Because the main function of glucose is to provide energy for the body, when insulin is no longer present there is no message sent to cells to take up glucose from the blood.

Instead, cells use fat and proteins to make energy, resulting in weight loss. If Type 1 diabetes goes untreated individuals with the disease will develop a life-threatening condition called ketoacidosis. This condition occurs when the body uses fats and not glucose to make energy, resulting in a build-up of ketone bodies in the blood.

It is a severe form of ketosis with symptoms of vomiting, dehydration, rapid breathing, and confusion and eventually coma and death. Upon insulin injection these severe symptoms are treated and death is avoided. Unfortunately, while insulin injection prevents death, it is not considered a cure.

People who have this disease must adhere to a strict diet to prevent the development of serious complications. Type 1 diabetics are advised to consume a diet low in the types of carbohydrates that rapidly spike glucose levels high-Glucose Index GI foods , to count the carbohydrates they eat, to consume healthy-carbohydrate foods, and to eat small meals frequently.

These guidelines are aimed at preventing large fluctuations in blood glucose. Frequent exercise also helps manage blood-glucose levels. Type 1 diabetes accounts for between 5 and 10 percent of diabetes cases. The other 90 to 95 percent of diabetes cases are Type 2 diabetes.

Type 2 diabetes is defined as a metabolic disease of insulin insufficiency, but it is also caused by muscle, liver, and fat cells no longer responding to the insulin in the body Figure 2.

In brief, cells in the body have become resistant to insulin and no longer receive the full physiological message of insulin to take up glucose from the blood. Thus, similar to patients with Type 1 diabetes, those with Type 2 diabetes also have high blood-glucose levels.

For Type 2 diabetics, the onset of symptoms is more gradual and less noticeable than for Type 1 diabetics:. The goal of healthcare providers is to prevent the second stage from happening. As with Type 1 diabetes, chronically high-glucose levels cause big detriments to health over time, so another goal for patients with Type 2 diabetes is to properly manage their blood-glucose levels.

The front-line approach for treating Type 2 diabetes includes eating a healthy diet and increasing physical activity.

According to the most recent data, about 3. The Centers for Disease Control Prevention CDC estimates that as of , We have the power to change some of the determinants of disease but not others.

The Diabetes Prevention Trial that studied lifestyle and drug interventions in more than three thousand participants who were at high risk for Type 2 diabetes found that intensive lifestyle intervention reduced the chances of getting Type 2 diabetes by 58 percent.

During pregnancy some women develop gestational diabetes. Gestational diabetes is characterized by high blood-glucose levels and insulin resistance. The exact cause is not known but does involve the effects of pregnancy hormones on how cells respond to insulin.

Gestational diabetes can cause pregnancy complications and it is common practice for healthcare practitioners to screen pregnant women for this metabolic disorder.

The disorder normally ceases when the pregnancy is over, but the National Diabetes Information Clearing House notes that women who had gestational diabetes have between a 40 and 60 percent likelihood of developing Type 2 diabetes within the next ten years.

As the term infers, prediabetes is a metabolic condition in which people have moderately high glucose levels, but do not meet the criteria for diagnosis as a diabetic. Over seventy-nine million Americans are prediabetic and at increased risk for Type 2 diabetes and cardiovascular disease.

The long-term health consequences of diabetes are severe. They are the result of chronically high glucose concentrations in the blood accompanied by other metabolic abnormalities such as high blood-lipid levels. People with diabetes are between two and four times more likely to die from cardiovascular disease.

Diabetes is the number one cause of new cases of blindness, lower-limb amputations, and kidney failure. Many people with diabetes develop peripheral neuropathy, characterized by muscle weakness, loss of feeling and pain in the lower extremities.

Type 1 diabetics begin insulin injections as soon as they are diagnosed. Type 2 diabetics may require oral medications and insulin injections to maintain blood-glucose levels in the target range. The symptoms of high blood glucose, also called hyperglycemia, are difficult to recognize, diminish in the course of diabetes, and are mostly not apparent until levels become very high.

The symptoms are increased thirst and frequent urination. Having too low blood glucose levels, known as hypoglycemia, is also detrimental to health. Hypoglycemia is more common in Type 1 diabetics and is most often caused by injecting too much insulin or injecting it at the wrong time.

The symptoms of hypoglycemia are more acute including shakiness, sweating, nausea, hunger, clamminess, fatigue, confusion, irritability, stupor, seizures, and coma. Hypoglycemia can be rapidly and simply treated by eating foods containing about ten to twenty grams of fast-releasing carbohydrates.

If symptoms are severe a person is either treated by emergency care providers with an intravenous solution of glucose or given an injection of glucagon, which mobilizes glucose from glycogen in the liver.

Some people who are not diabetic may experience reactive hypoglycemia. This is a condition in which people are sensitive to the intake of sugars, refined starches, and high glucose index foods. Individuals with reactive hypoglycemia have some symptoms of hypoglycemia.

Symptoms are caused by a higher than normal increase in blood-insulin levels. This rapidly decreases blood-glucose levels to a level below what is required for proper brain function. The major determinants of Type 2 diabetes that can be changed are overnutrition and a sedentary lifestyle.

Therefore, reversing or improving these factors by lifestyle interventions markedly improve the overall health of Type 2 diabetics and lower blood-glucose levels. In regard to carbohydrates the ADA recommends diabetics keep track of the carbohydrates they eat and set a limit. These dietary practices will help keep blood-glucose levels in the target range.

Metabolic syndrome refers to a medical condition in which people have three or more risk factors for Type 2 diabetes and cardiovascular disease. Studies vary, but people with metabolic syndrome have between a 9 and 30 times greater chance for developing Type 2 diabetes than those who do not have the syndrome.

Eating fresh, healthy foods not only stimulates your taste buds, but also can improve your quality of life and help you to live longer. As discussed, food fuels your body and helps you to maintain a healthy weight.

Nutrition also contributes to longevity and plays an important role in preventing a number of diseases and disorders, from obesity to cardiovascular disease. Some dietary changes can also help to manage certain chronic conditions, including high blood pressure and diabetes.

A doctor or a nutritionist can provide guidance to determine the dietary changes needed to ensure and maintain your health.

Fundamentals of Health and Physical Activity by Kerri Z. Delaney and Leslie Barker is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4. Skip to content Increase Font Size. Weight Management The health consequences of too much body fat are numerous, including increased risks for cardiovascular disease, Type 2 diabetes, and some cancers.

At the individual level: Purchase fewer prepared foods and eat more whole foods. Decrease portion sizes when eating or serving food. Eat out less, and when you do eat out choose low-calorie options. Walk or bike to work.

If this is not feasible, walk while you are at work. Take the stairs when you come upon them or better yet, seek them out.

Walk your neighborhood and know your surroundings. This benefits both health and safety. Watch less television. Support changes in school lunch programs. Participate in cleaning up local green spaces and then enjoy them during your leisure time.

Application of these factors to the food and drink consumed enables energy intake to be estimated. These days, energy intake is often measured in joules J or kilojoules kJ but many people are more familiar with Calories kcal. Energy expenditure is the sum of the basal metabolic rate BMR the amount of energy expended while at rest at a neutral temperature and in the fasting state , the thermic effect of food TEF otherwise known as dietary-induced thermogenesis and the energy expended in movement of all types.

A substantial proportion of total energy expenditure is accounted for by BMR, which is determined principally by body mass and body composition both of which vary with age and sex see below.

The TEF is the energy cost of digesting food and is rarely assessed separately. The actual amount of energy needed varies from person to person and depends on their basal metabolic rate BMR and how active they are. The basal metabolic rate BMR is the rate at which a person uses energy to maintain the basic functions of the body — breathing, keeping warm, and keeping the heart beating — when at complete rest.

An average adult will use around 1. Infants and young children tend to have a proportionately high BMR for their size due to their rapid growth and development. Men usually have a higher BMR than women since they tend to have more muscle.

Older adults usually have a lower BMR than younger people since their muscle mass tends to decrease with age. The BMR accounts on average for about three-quarters of an individual's energy needs. In addition to their BMR, people also use energy for movement of all types.

The amount of energy a person uses to perform daily tasks varies depending on factors such as his or her weight the heavier a person is the more energy is required for movement and their physical activity level. An estimate of the amount of energy an individual will need can be calculated by multiplying their BMR by a factor appropriate to the amount of activity that person does known as the Physical Activity Level PAL.

A PAL of 1. This applies to a large proportion of the UK population. In contrast, a PAL of 1. Using this approach and published data, estimates of average energy requirements for different population groups have been established.

Physical activity should be an important component of our daily energy expenditure. Many different types of activity contribute to our total physical activity, all of which form an integral part of everyday life. Total physical activity includes occupational activity, household chores, caregiving, leisure-time activity, transport walking or cycling to work and sport.

Physical activity can further be categorised in terms of the frequency, duration and intensity of the activity. Find out about how much physical activity adults and children should be doing on our page on physical activity recommendations.

The Estimated Average Requirements EARs for energy for the UK population were originally set by the Committee on the Medical Aspects of Food and Nutrition Policy COMA in and were reviewed in by the Scientific Advisory Committee on Nutrition SACN because the evidence base had moved on substantially, and over the same period, the levels of overweight and obesity in the UK had risen sharply.

EARs for an individual vary throughout the life course. During infancy and childhood, it is essential that energy is sufficient to meet requirements for growth, which is rapid during some stages of childhood.

Energy requirements tend to increase up to the age of years. On average, boys have slightly higher requirements than girls and this persists throughout adulthood, being linked to body size and muscle mass. After the age of 50 years, energy requirements are estimated to decrease further in women in particular and after age 60 years in men, which is partly due to a reduction in the basal metabolic rate BMR , as well as a reduced level of activity and an assumed reduction in body weight.

Find out more about the EARs for the UK population on our page on nutrient requirements. In order for people to maintain their bodyweight, their energy intake must equal their energy expenditure. Failure to maintain energy balance will result in weight change.

Energy balance can be maintained by regulating energy intake through the diet , energy expenditure adjusting physical activity level to match intake or a combination of both.

The average daily energy intake of UK adults aged years is kJ kcal for men and kJ kcal for women. These figures are below the EARs for both men and women and have been falling steadily, year on year, for some time. At the same time, the population has become ever more sedentary and population obesity levels are still on the increase.

Assuming the estimates of intake are correct, this means that energy expenditure levels have fallen to a greater extent than the reduction in dietary energy intake. This emphasizes the need for people to become more active because as energy intake falls, the greater the likelihood that micronutrient needs will no longer be met.

The easiest way to increase physical activity level is to incorporate more activity into daily routines, like walking or cycling instead of driving short distances and taking up more active hobbies such as gardening or rambling. Within the workplace, there are fewer opportunities for increasing activity levels, but stairs can be used instead of the lift and people can walk to speak to colleagues rather than using the phone or email.

Below are some examples of the amount of energy expended over a period of 30 minutes for a selection of activities:. If you have a more general query, please contact us. Please note that advice provided on our website about nutrition and health is general in nature. We do not provide any personal advice on prevention, treatment and management for patients or their family members.

If you would like a response, please contact us. We do not provide any individualised advice on prevention, treatment and management for patients or their family members.

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