COMORBITIES AND CONSEQUENCES OF OBESITY

Adult obesity is associated with a notable reduction in life expectancy and an increased rate of death from all causes. In addition to increased mortality, obesity and increased central adiposity are associated with increased morbidity. Obesity has now surpassed smoking as the number one cause of preventable disease and disability, and studies have found that the risk of developing a chronic disease increases with increasing body mass index (Perrault & Laferrère, 2020).

In Adults

DISEASES AND HEALTH CONDITIONS

People with obesity are at increased risk for many serious diseases and health conditions, including:

Metabolic

• Type 2 diabetes mellitus
• Insulin resistance with hyperinsulinemia
• Dyslipidemia

Cardiovascular

• Essential hypertension
• Coronary artery disease
• Left ventricular hypertrophy
• Cor pulmonale (right-sided heart failure)
• Myocardial steatosis (excessive lipid accumulation in the myocardium)
• Atrial fibrillation (significantly greater risk in those with metabolic syndrome)
• Accelerated atherosclerosis
• Pulmonary hypertension of obesity
• Deep vein thrombosis and pulmonary embolism

Gastrointestinal

• Gallbladder disease (cholecystitis and cholelithiasis)
• Non-alcoholic steatohepatitis (NASH) (the severe form of nonalcoholic fatty liver disease)
• Gastroesophageal reflux disease (GERD), erosive esophagitis, esophageal adenocarcinoma, and gastric cancer

Respiratory

• Obstructive sleep apnea
• Obesity hypoventilation syndrome (Pickwickian syndrome) caused by a reduced capacity of the respiratory system due to obesity
• Increased incidence of bronchial asthma (risk may be greater for nonallergic rather than allergic asthma)

Infection

• Increased susceptibility to infections, including postoperative nosocomial, respiratory, skin, and soft tissue infections

Central nervous system

• Stroke
• Idiopathic intracranial hypertension, which produces papilledema and vision loss
• Meralgia paresthetica (tingling, numbness, and burning pain in the outer part of the thigh caused by entrapment of the lateral femoral cutaneous nerve [LFCN])

Musculoskeletal

• Osteoarthrosis (noninflammatory joint disease)
• Osteoarthritis (inflammatory joint disease)
• Coxa vera (a deformity of the hip)
• Chronic lumbago (pain in the muscles and joints of the lower back)
• Gout related to the influence of BMI on hyperuricemia

Reproductive

• Anovulation and irregular menses
• Infertility
• Increased risk for maternal and perinatal complication
• Disorders of sexual arousal and orgasm in females
• Erectile dysfunction due to hormonal imbalance, endothelial dysfunction, insulin resistance, physical activity
• Hyperandrogenism and polycystic ovaries in women
• Hypogonadotropic hypogonadism in men

Genitourinary

• Glomerulosclerosis and obesity-related glomerulopathy
• Chronic kidney disease related to decreased filtration rate and albuminuria
• Nephrolithiasis (kidney stones)
• Stress incontinence in females

Cutaneous

• Intertrigo (bacterial and/or fungal inflammation caused by skin-to-skin friction)
• Acanthosis nigricans around neck, axilla, knuckles, and extensor surfaces related to hyperinsulinemia
• Hirsutism in females related to increased production of testosterone associated with visceral obesity
• Skin infections, e.g., cellulitis and carbuncles
• Striae distensae (stretch marks)

Malignancies

• Some cancers (endometrial, prostate, breast, colon, gallbladder), which may be due to alterations in sex hormone metabolism, insulin and insulin-like growth factor levels, and adipokine pathways

Extremities

• Venous varicosities
• Lower extremity venous and/or lymphatic edema

Psychological

• Mental illness such as chronic depression, anxiety, and other mental disorders
• Social stigmatization
• Low quality of life

Miscellaneous

• Reduced mobility
• Difficulty maintaining personal hygiene

(Hamdy, 2022; CDC, 2021e; Perreault & Laferrère, 2020; Brennan, 2021b)

COGNITIVE EFFECTS

Scientists have found that increased BMI, waist-hip ratio, and waist size are associated with lower cerebral blood flow, and that a 1 cm increase in waist size produces the same reduction in blood flow as one year of aging.

Obesity promotes the development of vascular cognitive impairment and also increases the incidence of Alzheimer’s disease. Studies indicate that aging and obesity exert synergistic negative effects on cognition, and that early midlife obesity is associated with impaired memory and executive function later in life (Knight et al., 2021).

Recent evidence has shown multiple underlying mechanisms for this development, including inflammation, hyperinsulinemia/insulin resistance, and disruption at the microbiota-gut-brain axis. These are seen to bring about pathophysiologic insults at the level of blood vessel endothelium, an early event in the development of cognitive impairment and dementia. Increasingly, evidence that both aging and obesity cause structural and functional impairment in the cerebral microcirculation play a role in the pathogenesis of both vascular cognitive impairment and Alzheimer’s disease (Balasubramanian et al., 2021).

The blood-brain barrier (BBB) is vital for maintenance of proper neuronal function and both aging and obesity promote BBB disruption. This disruption precedes and activates neuroinflammation and neurodegeneration, causing declines in microvascular integrity, leading to cognitive decline (Olsthoorn et al., 2021).

Both aging and obesity are also associated with altered gut microbiome, which has been linked to impaired cerebral blood flow, BBB impairment, and cognitive dysfunction. Adipose tissue dysfunction with its heightened inflammatory status also contributes significantly to systemic inflammation in obesity, playing an important role in impaired neuronal function and the pathogenesis of both vascular cognitive impairment and Alzheimer’s disease (Balasubramanian et al., 2021).

MOTOR EFFECTS

In adults, obesity contributes to bone and joint damage, which can increase the risk for accidents and personal injury. These may include:

• Osteoarthritis
• Disc herniation
• Spinal disorders
• Back pain
• Obesity-caused pseudotumor cerebre (“false brain tumor”) associated with confusion, disorientation, headache, and visual problems
  (ASMBS, 2021a)

For both men and women, the risk of developing a walking disability rises with increasing weight status. Older people who are obese have an accelerated risk of developing a walking disability (GWU, 2019).

In Children and Adolescents

Obesity affects children and adolescents across all age groups, and the increasing prevalence of childhood and adolescent obesity is associated with a rise in comorbidities previously considered “adult diseases.” In the United States, close to one third of children over age 2 are overweight or obese, and for the first time since the 1900s, life expectancy for children is eroding because of obesity (Martinelli, 2022).

DISEASES AND HEALTH CONDITIONS

Endocrine

• Prediabetes (increases the risk for developing type 2 diabetes mellitus)
• Type 2 diabetes mellitus (leads to more rapid progression of diabetes-related complications in later life)
• Metabolic syndrome (a cluster of risk factors for type 2 diabetes and atherosclerosis, which includes abdominal obesity, hyperglycemia, dyslipidemia, and hypertension)
• Hyperandrogenism in females and risk for early-onset polycystic ovary syndrome characterized by hirsutism, menstrual irregularities, and dermatologic problems
• Accelerated linear growth and bone age associated with marked hyperinsulinemia
• Gynecomastia in males related to the stimulating effects of fat on estrogen production
• Early onset of sexual maturation

Cardiovascular

• Essential hypertension, best assessed using ambulatory blood pressure monitoring rather than casual office BP measurement
• Dyslipidemia, particularly in those with central fat distribution and increased adiposity, including elevated concentrations of LDL cholesterol and triglycerides and decreased concentration of HDL cholesterol
• Alterations in cardiac structure and function similar to those seen in middle-aged adults, including increased left ventricular mass, increased left ventricular and left atrial diameter, greater epicardial fat, and systolic and diastolic dysfunction
• Premature atherosclerotic cardiovascular disease with endothelial dysfunction of the blood vessels, aortic intima-media thickening, development of early aortic and coronary arterial fatty streaks and fibrous plaques, and increased arterial stiffness

Gastrointestinal

• Nonalcoholic fatty liver disease, the most common cause of liver disease in children, resulting in fatty infiltration and inflammation of the liver
• Cholelithiasis (gallstones), with obesity being the most common cause in children (greater for girls than boys) without predisposing conditions, the risk increasing with increasing BMI

Pulmonary

• Obstructive sleep apnea (complete obstruction of the upper airway during sleep and cessation of air movement despite ongoing respiratory effort)
• Obesity and alveolar hypoventilation syndrome (Pickwickian syndrome) during wakefulness, a rare but life-threatening disorder that requires prompt diagnosis and therapy
• Hypoventilation during sleep in the absence of airway obstruction, possibly due to the restrictive ventilator defect caused by abdominal distribution of fat
• Increased predisposition for respiratory infections and bronchial asthma

Orthopedic

• Slipped capital femoral epiphysis, typically occurring in early adolescence, related to increased shear forces at the capital femoral growth plate
• Idiopathic genu valgum (commonly called “knock-knees”), characterized by deviation of the knees toward the midline of the body
• Tibia varus (Blount disease), characterized by progressive bowing of the legs and tibial torsion as a result of excessive abnormal weight bearing, more commonly among individuals with darkly pigmented skin
• Fractures, since bone development is not always able to compensate for excess weight, with the resulting imbalance putting undue stress on developing bones
• Increased risk for joint damage or osteoarthritis in adulthood

Neurologic

• Idiopathic intracranial hypertension (pseudotumor cerebri), which presents with signs and symptoms of a brain tumor and can result in severe visual impairment or blindness

Dermatologic

• Intertrigo (an inflammatory rash caused by skin-to-skin friction in warm, moist areas of the body)
• Furunculosis (boils), or small abscesses involving hair follicles
• Hidradenitis suppurative, or inflammatory nodules or deep fluctuant cysts in the skin of the axillae and groin
• Acanthosis nigricans, or areas of dark velvety discoloration in body folds and creases, particularly the armpits, groin, and neck, associated with insulin resistance
• Striae distensae (stretch marks) caused by mechanical factors, possibly acting in concert with hormonal factors such as high levels of adrenocorticosteroids

(Skelton & Klish, 2021; Kansra et al., 2021)

COGNITIVE EFFECTS

Excess visceral adipose tissue can exceed metabolic dysregulation and affect cognitive function and brain health. In children with obesity, the level of intelligence can be affected. Significant impairments in cognitive functions, especially executive, attention, retention, intelligence, and cognitive flexibility, have been observed.

Overweight children have spatial cognitive task problems, with differences for motor ability and mental rotation accuracy, a function of visual representation. Adolescents who are obese have been found to have lower learning achievement compared to teens who are of normal weight. The relationship between compromised executive function and obesity may be partly explained by BMI-associated reduced cortical thickness in the prefrontal cortex of the brain (Ghosal et al., 2021; Alam et al., 2020; Ronan et al., 2019).

MOTOR EFFECTS

Childhood obesity and overweight are associated with the appearance of coordination deficit disorder and can cause impaired motor performance, altered postural control, and modification of motor coordination.

Childhood obesity can result in vitamin deficiencies, hormonal imbalances, and increased stress and tension that can affect bone growth and overall musculoskeletal health, causing deformity, pain, limited mobility, and diminished quality of life.

Obese children often have difficulties with coordination, including:

• Clumsiness
• Problems with gross motor coordination (jumping, hopping, balancing on one foot)
• Problems with visual or fine-motor coordination (e.g., writing, tying shoelaces)

These problems may impair or limit a child’s ability to exercise, potentially resulting in more weight gain (Barros et al., 2022; AAOS, 2019).

Psychological and Psychosocial Effects of Overweight and Obesity

Psychological effects refer to an individual’s thoughts, emotions, and behaviors; and psychosocial effects refer to the interactions and relationships between an individual, family, peers, and community.

Overweight and obesity psychological effects can include:

• Depression (adults have a 55% higher risk of developing depression over their lifetime)
• Anxiety
• Stress
• Eating disorders, including bulimia nervosa (BN), binge-eating disorder (BED), night-eating syndrome (NES), and anorexia nervosa (AN)
• Substance abuse
• Sleeping disorders, including insomnia and restless leg syndrome (Willis-Ekbom disease) associated with depression or anxiety
• Increased incidence of:
  • Bipolar disorder
  • Panic disorder
  • Agoraphobia
  (Kansra et al., 2021; Skelton & Klish, 2021; Vafiadis, 2021)

Psychosocial issues affecting individuals with overweight/obesity include:

• Quality of life problems related to physical and occupational functioning. Persons with obesity may be unable to physically attend fun activities or events, travel, or visit with friends and family, which can result in social isolation, loneliness, and more difficulty coping with problematic situations.
• Weight bias/discrimination, one of the biggest challenges for those with overweight/obesity issues, is widespread and can lead to discriminatory behavior affecting a person’s self-esteem, schooling, employment opportunities, and the quality of healthcare they receive (see below).
• Adverse outcomes for overweight females and males in comparison to their non-overweight peers include having completed less schooling, having earned less money, and having less likelihood of getting married.
• Internalization of society’s negative views of obesity, which causes embarrassment and dissatisfaction with their appearance, and may cause anxiety over being judged for how they look.
  (Vafiadis, 2021; Schwarz, 2020)

Children and adolescents experience increased risk of social isolation and poorer peer relationships, discrimination, harassment, and poorer self-esteem in comparison with their normal-weight peers. These factors can worsen the quality of life for a child or adolescent with obesity, with the potential for long-lasting ramifications, as obesity in childhood often results in obesity in adulthood.

In a recent study, children and adolescents with obesity, along with their parents and caregivers, reported decreased emotional and social quality of life compared with healthy nonoverweight children and adolescents. Those with severe obesity reported diminished quality of life similar to that reported by children and adolescents with cancer (Mazurak et al., 2021; Vafiadis, 2021).

WEIGHT BIAS AND STIGMA

Prejudice against “fat” people is one of the deepest and most widely shared prejudices the public holds. The pervasively hostile, discriminating environment that marginalized people find themselves in is a source of constant physical and psychological stress.

Stigmatization is mostly based on a misunderstanding of the complex causes of obesity, with people attributing weight gain to personal responsibility, resulting in blaming obese individuals for their condition and enabling the negative stereotyping of them as lazy and lacking in willpower (Schwarz, 2020).

Microaggressions against obese people are so pervasive and normalized that people often do not recognize them as stigmatizing. In fact, these negative attitudes are so embedded that many obese individuals are complicit in their own stigmatization, believing they deserve it or that those expressing prejudice are simply stating a fact. Studies show that obesity is generally viewed as a self-inflicted condition and is under the individual’s control.

Studies have confirmed that even at a very young age, children contribute to the stigmatization of overweight individuals. Weight stigma has been shown already to be developed in children from age 3 and becomes significantly stronger in children by age 5. These children have described overweight people as ugly, unpopular, lazy, liars, cheats, dirty, and stupid. Girls display stronger weight stigma than boys (Jenull et al., 2021; Skelton & Klish, 2021).

Weight Stigma in Education

Weight stigma in the educational environment is very common and is one of the major reasons for victimization. Weight stigma in these settings comes from different sources. Students aren’t just victimized by their peers, but their teachers (particularly, but not exclusively, physical education teachers) can be common perpetrators.

Weight stigma can prevent students from moving into higher education settings such as master’s and doctoral programs, as they are significantly less likely to be accepted to colleges or universities following an in-person interview. Those that do get accepted are likely to receive less financial support than normal-weight peers (World Obesity, 2019).

Weight Stigma in the Workplace

Stigma is present at every point in the employment process. This includes career counseling, interviewing and hiring practices, salary disparities, fewer promotions, harsher disciplinary actions, and higher termination rates. Workers with obesity are less likely to work in a sales or customer-facing position and are paid less than their normal-weight counterparts for the same work. This is more pronounced for women than men.

Though it is illegal to discriminate in employment based on sexual identity or orientation, pregnancy, race, national origin, religion, or disability, it is still legal to discriminate because of weight. Currently, there are no federal laws protecting an individual from weight-based workplace discrimination. Throughout the country, only one state (Michigan) has a law protecting potential employees from bias based on weight (World Obesity, 2019; Sherrell, 2021).

Weight Stigma in Close Relationships

Close relationships, including spouses/partners, children, parents, and siblings, have been found and documented to be the most common source of stigmatizing comments. In some cases, this source of stigma generates the most harmful stigmatizing encounters.

Parents of children with obesity may experience weight stigma by association, which may have direct repercussions for them, their children, and the parent-child relationship (World Obesity, 2019; Lee et al., 2021).

Weight Stigma in the Media

Weight prejudice is apparent in almost all forms of media, including children’s shows, in which characters with obesity are often stereotyped as clumsy, lazy, without friends, and present for comic relief. On television and in the movies, thin people are shown to be healthier, more successful, more likeable, and more likely to find love.

Fat people are often used for motivation. In such examples, a fat person loses weight and becomes a thin, successful and happier person. Before-and-after weight-loss photos are often posted on social media, which is also a major promoter of disordered diet trends and unproven “health tips.”

Magazines, blogs, and news publications mostly use images of thin people and run stories about weight loss and the dangers of fat. These publications also glorify restrictive eating patterns and promote harmful diet trends (World Obesity, 2019).

Weight Stigma in Healthcare Settings

Medical professionals in all areas, nurses, and students in healthcare have been found to express both explicit and implicit bias toward overweight and obese individuals. Physicians generally have lower levels of respect for those with higher BMIs and generally spend less time during an office visit with them compared to their healthy-weight counterparts. Physicians can also be a direct source of stigmatizing comments. It has been found that 53% of people with overweight and obesity reported having been a recipient of inappropriate comments about their weight from their doctor.

Physicians view persons with obesity as less compliant, less motivated, less disciplined, less adherent to medications, less trustworthy, and more annoying. Additionally, as a patient’s BMI increases, physicians report less patience, less desire to help the person, less respect for the patient, and a greater perception of the patient as a waste of time.

Studies of self-reported attitudes among nurses indicated:

• 31% “would prefer not to care for individuals affected by obesity”
• 24% agreed that individuals affected by obesity “repulsed them”
• 12% “would prefer not to touch individuals affected by obesity”

In addition to stigma arising from the clinician-patient relationship, many people with obesity report a stigmatizing physical healthcare environment, which can include gowns, blood pressure cuffs, chairs, and examination tables that are unable to accommodate people with obesity (OAC, 2022; Fulton & Srinivasan, 2021; World Obesity, 2019).

When weight stigma is experienced in healthcare settings, it can result in avoidance of future care, reduced adherence to services, lower trust and communication with healthcare professionals, thereby resulting in reduced quality of care and exacerbated health disparities.

About 52% of women who are overweight or obese say their weight has been a barrier to receiving appropriate healthcare. These women are less likely to receive recommended health screenings. Obese patients are more likely to cancel or delay appointments and preventive healthcare services. They are also more likely to avoid seeking healthcare altogether. The long-term effect of avoiding healthcare services is that people with obesity may present with more advanced conditions that are then more difficult to treat (Villines, 2021).

BULLYING AND WEIGHT

Bullying is a pervasive societal issue consistently linked to negative outcomes that are emotionally, socially, behaviorally, and medically related. Most youth will encounter this negative event in their childhood either through being a perpetrator, being victimized, or witnessing others being bullied.

Characteristics of bullying include:

• Intent to harm
• Repetition over time or across environments
• Imbalance of power between perpetrator and victim

Bullying is defined as any unwanted aggressive behavior(s) by family members, other youth, a group of youths who are not siblings, or current dating partners; and it involves an observed or perceived power imbalance, is repeated multiple times, or is highly likely to be repeated. There are four types of bullying: physical, verbal, social or relational, and electronic. Most bullying incidents occur in the presence of bystanders, leading researchers to believe that bullying is a group phenomenon (Damme, 2019).

Among children and adolescents, weight stigma is primarily expressed through teasing and bullying. Adolescents identify weight as the primary reason for harassment among their peers. Youth who are overweight and obese are more likely to experience bullying victimization, including relational, verbal, and physical, than their average-weight counterparts.

In general, females are at greater risk of psychological distress and internalizing disorders, including generalized anxiety and major depression as a result of bullying. Social and emotional consequences are worse and occur at lower BMIs for girls/women than for boys/men (Patte et al., 2021).