How do excess fats affect health? Why do obese people are prone to illnesses and mortality? It is vital to know how extreme weight affects the body, and how it is linked to complications of the heart, bones, and mental stability. Comprehension regarding these matters could lead us to effective solutions that would decrease the rate of obesity, and the incidence of mortality that follows.
How Obesity Affects the Heart
Obesity can lead to diseases caused by heart complications like congestive heart failure, arrhythmias, coronary artery disease, hypertension, and stroke. Extra weight means extra work for the heart, as the heart pumps a larger mass of blood in each heart beat. This puts a strain on the heart over time that would later result to a bigger heart with muscles of lesser strength. Thus, a dysfunctional heart would lead to irregular heart beat (arrhythmia), difficulty of breathing (apnea), and even heart failure.
High blood pressure is affected by obesity due to several factors caused by extreme weight gain such as increased inflammation in the body through adipokines, excess levels of insulin in the blood, insulin resistance, over-activity of the sympathetic nervous system and a disordered sleep pattern. The blood pressure could as well rise due to difficulty of breathing while sleeping (sleep apnea), pulmonary complication, dysfunction of the left part of the heart, and thromboembolism (blood clot in the arteries of the heart).
Risk of stroke is higher in obese people due the mentioned incidences such as heart strain, arrhythmia, high blood pressure, and diabetes. Though the connection between stroke and obesity is still not fully understood, the high level of bad cholesterol (or Low-density lipoprotein) is considered as a great factor of stroke. These bad fats clog the arteries of the heart that hinder the blood flow, resulting to death of veins, tissues and muscles, or worse, heart attack.
How Obesity Affects the Bones
Fats affect bone metabolism and bone health in several ways. As bone formation and fat cells formation are often interlaced. First, because osteoblasts (bone forming cells) and adipocytes (energy storing cells i.e. fat cells) are derived from a common mesenchymal stem cell. Therefore agents that inhibit adipogenesis stimulate osteoblast differentiation, vice versa. In simpler words, formation of more fats is always equal to lesser formation of bone cells, and the other way around. Second, aging related bone degradation consequences to build up of more fats in the body. Third, obesity causes an elevated oxidative stress and increased production of proinflammatory cytokines, which are both responsible for initiation of diseases that involves inflammation such arthritis and osteoarthritis. Furthermore, fat cells are infiltrated with macrophages that induce inflammation. Macrophages trigger inflamed joints causing pain and bone degradation over time. Also, adipose tissues are not only fat storing cells but also an active endocrine tissue that produces several components like leptin. Leptin is a kind of adipokines which does not only stimulate inflammation but also affects energy expenditure, appetite and neuroendocrine functions.
Excessive weight accelerates the wear of joints and spine. Obese people have a hard time squatting, climbing or running because there is a greater force at the patella (kneecap), which is three times the body weight while walking. Extremely overweight people also have a greater compressive force on their spinal column that leads to disc pathology and back pain.
Imagine wearing a backpack backwards with 50-75 pounds in it for a day and you get the idea.
How Obesity Affects Mental Health
Obesity can lead to mental disorder (i.e. depression), and mental disorders can lead to obesity. As for some depressed and anxious people, eating brings pleasure due to the trigger of dopamine release, a feel good neurotransmitter. That pleasure could be a problem when it led to binge eating, and eventually food addiction. Research shows that obese people have lesser sensitive dopamine receptors to sugar-rich and fats-rich foods. This means that less pleasure are induced in the brain while and after eating, which cause them to consume more food to fulfill that certain satisfaction.
Obesity, as we know, triggers inflammation that consecutively results to unhealthy cells, including brain cells. Though fat cells could not enter the brain due to the blood brain barrier, a substance called interleukin 1 that is created by fat cells could pass through and weaken that barrier. Once Interleukin 1 passes the part of the brain called hippocampus, it induces inflammation that affects the synapses of the brain and the traffic of messages within the neurons. This instance results to poor memory and difficulty in learning. Inflammation of the brain can also decrease the total volume of the brain, which makes obese people more susceptible to dementia.