Weight loss

Weight loss

Weight loss, in the context of medicine, health, or

Intentional

Intentional weight loss is the loss of total body mass as a result of efforts to improve

For weight loss to be permanent, changes in diet and lifestyle must be permanent as well.[14]^[15][16] There is evidence that counseling or exercise alone do not result in weight loss, whereas dieting alone results in meaningful long-term weight loss, and a combination of dieting and exercise provides the best results.^[17] Meal replacements, orlistat, a very-low-calorie diet, and primary care intensive medical interventions can also support meaningful weight loss.^[18][19]

Techniques

Diet and exercise

The least intrusive weight loss methods, and those most often recommended, are adjustments to eating patterns and increased physical activity, generally in the form of exercise.^[20] The World Health Organization recommends that people combine a reduction of processed foods high in saturated fats, sugar and salt,^[21] and reduced caloric intake with an increase in physical activity.^[22] Both long-term exercise programs and anti-obesity medications reduce abdominal fat volume.^[23] Self-monitoring of diet, exercise, and weight are beneficial strategies for weight loss,^[20][24][25] particularly early in weight loss programs.^[26] Research indicates that those who log their foods about three times per day and about 20 times per month are more likely to achieve clinically significant weight loss.^[20][27]

Permanent weight loss depends on maintaining a negative energy balance and not the type of

Increasing water intake can reduce weight by increasing thermogenesis, by reducing food intake, and by increasing fat oxidation.^[30] Persons dieting for weight loss have demonstrated the weight-reducing effects of increased water consumption.^[31] Among adults in the U.S. there is a significant association between inadequate hydration and obesity.^[32]

Medications

Other methods of weight loss include use of anti-obesity drugs that decrease appetite, block fat absorption, or reduce stomach volume.^{[citation needed]} Obesity has been resistant to drug-based therapies, with a 2021 review stating that existing medications are "often delivering insufficient efficacy and dubious safety".^[33]

Bariatric surgery

In 2008, between US$33 billion and $55 billion was spent annually in the US on weight-loss products and services, including medical procedures and pharmaceuticals, with weight-loss centers taking between 6 and 12 percent of total annual expenditure. Over $1.6 billion per year was spent on weight-loss supplements. About 70 percent of Americans' dieting attempts are of a self-help nature.^[39][40]

In Western Europe, sales of weight-loss products, excluding prescription medications, topped €1,25 billion (£900 million/$1.4 billion) in 2009.^[40]

The scientific soundness of commercial diets by commercial weight management organizations varies widely, being previously non-evidence-based, so there is only limited evidence supporting their use, because of high attrition rates.^{[41][42][43][44][45][46]} Commercial diets result in modest weight loss in the long term, with similar results regardless of the brand,^{[43][45][47][48]} and similarly to non-commercial diets and standard care.^[41][3] Comprehensive diet programs, providing counseling and targets for calorie intake, are more efficient than dieting without guidance ("self-help"),^[41][49][48] although the evidence is very limited.^[46] The National Institute for Health and Care Excellence devised a set of essential criteria to be met by commercial weight management organizations to be approved.^[44]

Unintentional

Characteristics

Unintentional weight loss may result from loss of body fats, loss of body fluids, muscle atrophy, or a combination of these.^[50][51] It is generally regarded as a medical problem when at least 10% of a person's body weight has been lost in six months^[50][52] or 5% in the last month.^[53] Another criterion used for assessing weight that is too low is the body mass index (BMI).^[54] However, even lesser amounts of weight loss can be a cause for serious concern in a frail elderly person.^[55]

Unintentional weight loss can occur because of an inadequately nutritious diet relative to a person's energy needs (generally called

Serious weight loss may reduce quality of life, impair treatment effectiveness or recovery, worsen disease processes and be a risk factor for high mortality rates.^[50][55] Malnutrition can affect every function of the human body, from the cells to the most complex body functions, including:^[54]

• immune response;
• wound healing;
• muscle strength (including respiratory muscles);
• renal capacity and depletion leading to water and electrolyte disturbances;
• thermoregulation; and
• menstruation.

Malnutrition can lead to vitamin and other deficiencies and to inactivity, which in turn may pre-dispose to other problems, such as pressure sores.^[54] Unintentional weight loss can be the characteristic leading to diagnosis of diseases such as cancer^[50] and type 1 diabetes.^[59] In the UK, up to 5% of the general population is underweight, but more than 10% of those with lung or gastrointestinal diseases and who have recently had surgery.^[54] According to data in the UK using the Malnutrition Universal Screening Tool ('MUST'), which incorporates unintentional weight loss, more than 10% of the population over the age of 65 is at risk of malnutrition.^[54] A high proportion (10–60%) of hospital patients are also at risk, along with a similar proportion in care homes.^[54]

Causes

Disease-related

Disease-related malnutrition can be considered in four categories:^[54]

Weight loss issues related to specific diseases include:

• As
  dyspnea (labored breathing).^[56]
• Cancer, a very common and sometimes fatal cause of unexplained (
  idiopathic) weight loss. About one-third of unintentional weight loss cases are secondary to malignancy. Cancers to suspect in patients with unexplained weight loss include gastrointestinal, prostate, hepatobiliary (hepatocellular carcinoma, pancreatic cancer
  ), ovarian, hematologic or lung malignancies.
• People with HIV often experience weight loss, and it is associated with poorer outcomes.^[60] Wasting syndrome is an AIDS-defining condition.^[60]
• mesenteric ischemia^[61]
  and many other GI conditions.
• Infection. Some infectious diseases can cause weight loss.
  AIDS, Whipple's disease
  and some other subacute or occult infections may cause weight loss.
• vomiting
  and nausea. This can cause weight loss.
• Cardiac disease
  . Cardiovascular disease, especially congestive heart failure, may cause unexplained weight loss.
• Connective tissue disease
• Oral, taste or dental problems (including infections) can reduce nutrient intake leading to weight loss.[52]

Therapy-related

Medical treatment can directly or indirectly cause weight loss, impairing treatment effectiveness and recovery that can lead to further weight loss in a vicious cycle.

Social conditions such as poverty, social isolation and inability to get or prepare preferred foods can cause unintentional weight loss, and this may be particularly common in older people.[64] Nutrient intake can also be affected by culture, family and belief systems.^[52] Ill-fitting dentures and other dental or oral health problems can also affect adequacy of nutrition.^[52]

Loss of hope, status or social contact and spiritual distress can cause depression, which may be associated with reduced nutrition, as can fatigue.^[52]

Myths

Some popular beliefs attached to weight loss have been shown to either have less effect on weight loss than commonly believed or are actively unhealthy. According to Harvard Health, the idea of

Obesity increases health risks, including diabetes, cancer, cardiovascular disease, high blood pressure, and non-alcoholic fatty liver disease, to name a few. Reduction of obesity lowers those risks. A 1-kg loss of body weight has been associated with an approximate 1-mm Hg drop in blood pressure.^[67] Intentional weight loss is associated with cognitive performance improvements in overweight and obese individuals.^[68]

See also

• Anorexia
• Cigarette smoking for weight loss
• Dieting
• Physical exercise
• Weight gain

References

External links

Wikimedia Commons has media related to Weight loss.

Wikibooks has a book on the topic of: Lentis/The Weight Loss Industry in the United States

Wikibooks has a book on the topic of: Fundamentals of Human Nutrition/Weight management

• Weight loss at
  Curlie
• Weight-control Information Network Archived 12 February 2015 at the
  U.S. National Institutes of Health
• Nutrition in cancer care, US National Library of Medicine
• Unintentional weight loss, MedlinePlus