Body mass index (BMI) is a value derived from the mass (weight) and height of a person. The BMI is defined as the body mass divided by the square of the body height, and is expressed in units of kg/m2, resulting from mass in kilograms and height in metres.
Dieting is the practice of eating food in a regulated way to decrease, maintain, or increase body weight, or to prevent and treat diseases such as diabetes and obesity. As weight loss depends on calorie intake, different kinds of calorie-reduced diets, such as those emphasising particular macronutrients, have been shown to be no more effective than one another. As weight regain is common, diet success is best predicted by long-term adherence. Regardless, the outcome of a diet can vary widely depending on the individual.
Obesity is a condition in which excess body fat has accumulated to such an extent that it may have a negative effect on health. People are classified as obese when their body mass index (BMI)—a measurement obtained by dividing a person's weight by the square of the person's height —is over 30 kg/m2; the range 25–30 kg/m2 is defined as overweight. Some East Asian countries use lower values to calculate obesity.
Weight loss, in the context of medicine, health, or physical fitness, refers to a reduction of the total body mass, by a mean loss of fluid, body fat, or lean mass. Weight loss can either occur unintentionally because of malnourishment or an underlying disease, or from a conscious effort to improve an actual or perceived overweight or obese state. "Unexplained" weight loss that is not caused by reduction in calorific intake or exercise is called cachexia and may be a symptom of a serious medical condition. Intentional weight loss is commonly referred to as slimming.
Basal metabolic rate (BMR) is the rate of energy expenditure per unit time by endothermic animals at rest. It is reported in energy units per unit time ranging from watt (joule/second) to ml O2/min or joule per hour per kg body mass J/(h·kg). Proper measurement requires a strict set of criteria to be met. These criteria include being in a physically and psychologically undisturbed state and being in a thermally neutral environment while in the post-absorptive state (i.e., not actively digesting food). In bradymetabolic animals, such as fish and reptiles, the equivalent term standard metabolic rate (SMR) applies. It follows the same criteria as BMR, but requires the documentation of the temperature at which the metabolic rate was measured. This makes BMR a variant of standard metabolic rate measurement that excludes the temperature data, a practice that has led to problems in defining "standard" rates of metabolism for many mammals.
In physiology and medicine, the body surface area (BSA) is the measured or calculated surface area of a human body. For many clinical purposes, BSA is a better indicator of metabolic mass than body weight because it is less affected by abnormal adipose mass. Nevertheless, there have been several important critiques of the use of BSA in determining the dosage of medications with a narrow therapeutic index, such as chemotherapy.
Weight gain is an increase in body weight. This can involve an increase in muscle mass, fat deposits, excess fluids such as water or other factors. Weight gain can be a symptom of a serious medical condition.
Calorie restriction is a dietary regimen that reduces food intake without incurring malnutrition. "Reduce" can be defined relative to the subject's previous intake before intentionally restricting food or beverage consumption, or relative to an average person of similar body type.
The body fat percentage (BFP) of a human or other living being is the total mass of fat divided by total body mass, multiplied by 100; body fat includes essential body fat and storage body fat. Essential is necessary to maintain life and reproductive functions. The percentage of essential body fat for women is greater than that for men, due to the demands of childbearing and other hormonal functions. Storage body fat consists of fat accumulation in adipose tissue, part of which protects internal organs in the chest and abdomen. A number of methods are available for determining body fat percentage, such as measurement with calipers or through the use of bioelectrical impedance analysis.
Childhood obesity is a condition where excess body fat negatively affects a child's health or well-being. As methods to determine body fat directly are difficult, the diagnosis of obesity is often based on BMI. Due to the rising prevalence of obesity in children and its many adverse health effects it is being recognized as a serious public health concern. The term overweight rather than obese is often used when discussing childhood obesity, especially in open discussion, as it is less stigmatizing. The prevalence of childhood obesity is known to differ by sex and gender.
The Trim and Fit (TAF) programme was a weight loss programme that targeted child obesity in Singapore schools between 1992 and 2007. Introduced by the Ministry of Education, schoolchildren under the programme were educated on nutrition, calorie control, and participated in intense physical exercise and activities.
Obesity in the United States is a major health issue resulting in numerous diseases, specifically increased risk of certain types of cancer, coronary artery disease, type 2 diabetes, stroke, cardiovascular disease, as well as significant increases in early mortality and economic costs.
Being overweight or fat is having more body fat than is optimally healthy. Being overweight is especially common where food supplies are plentiful and lifestyles are sedentary.
The Harris–Benedict equation is a method used to estimate an individual's basal metabolic rate (BMR).
Obesity has been observed throughout human history. Many early depictions of the human form in art and sculpture appear obese. However, it was not until the 20th century that obesity became common — so much so that, in 1997, the World Health Organization (WHO) formally recognized obesity as a global epidemic and estimated that the worldwide prevalence of obesity has nearly tripled since 1975. Obesity is defined as having a body mass index (BMI) greater than or equal to 30 kg/m2, and in June 2013 the American Medical Association classified it as a disease.
Diet plays an important role in the genesis of obesity. Personal choices, food advertising, social customs and cultural influences, as well as food availability and pricing all play a role in determining what and how much an individual eats.
Weight management includes the techniques and physiological processes that contribute to a person's ability to attain and maintain a certain weight. Most weight management techniques encompass long-term lifestyle strategies that promote healthy eating and daily physical activity. Moreover, weight management involves developing meaningful ways to track weight over time and to identify ideal body weights for different individuals.
Management of obesity can include lifestyle changes, medications, or surgery. Although many studies have sought effective interventions, there is currently no evidence-based, well defined, and efficient intervention to prevent obesity.
This article provides a global overview of the current trends and distribution of metabolic syndrome. Metabolic syndrome refers to a cluster of related risk factors for cardiovascular disease that includes abdominal obesity, diabetes, hypertension, and elevated cholesterol.
Obesity is defined as the excessive accumulation of fat and is predominantly caused when there is an energy imbalance between calorie consumption and calorie expenditure. Childhood obesity is becoming an increasing concern worldwide, and Australia alone recognizes that 1 in 4 children are either overweight or obese.
