There are many complications of obesity, the individual may experience some or many. Many of the complications are rely on other factors such as family history. The psychological aspect should not be underestimated and will affect how the individual is managed. Bullying is common in children and needs to be addressed urgently, for both the emotional well-being of the child, and also to prevent the child's inhibition of taking exercise in the presence of other.
Obese adults have a higher risk of insulin resistance. It may also occur in obese children, and may also present with high blood pressure and a change in blood lipids. A family history of insulin resistance or diabetes and ethnic background are known to be established risk factors. While an increased amount of body fat is likely to be a risk factor for insulin resistance, a link has not been established by research. Resistance to insulin gives a 50% chance of developing type 2 diabetes later in life.
Type 2 diabetes now accounts for up to 50% of cases of diabetes in children in North America. This is overwhelmingly seen in specific ethnic groups: Hispanics in North America, and South Asians in the UK. Presentation may be with polyuria and polydipsia, or raised urinary glucose may be detected during random testing, or while being investigated for an intercurrent illness. As type 2 diabetes in children is largely a recent phenomenon, the long term complications are not yet fully established. It is likely that they would include the typical microvascular and macrovascular complications seen in adults, but presenting at an earlier age.
Polycystic ovarian syndrome (PCOS) is associated with obesity, yet it has not been established whether it is the cause, or whether it occurs as a result of obesity. Along with weight gain, the affected individual may also experience irregular periods and hirsutism.
Obesity has long been recognised as a cause of obstructive sleep apnoea. During sleep the muscles maintaining the patency of the airway relax. In obese individuals the increased tissue mass in the neck exert an increased pressure on the airway thereby effectively causing an obstruction. The individual may stop breathing momentarily, before waking suddenly by the struggle to breath against a blocked throat. This may result in snoring, and a loss of sleep that may lead to daytime sleepiness that can lead to impairment of work performance and driving.
Obesity may lead to the build up of fatty deposits in the liver, called non-alcoholic steatotic hepatitis (NASH). Up to 50% of obese children have signs of this disease. Radiological changes may be seen and blood tests may show raised aminotransferases, indicating liver cell damage. This condition may improve by losing weight, however in a small number of cases it may progress to cirrhosis that may ultimately require liver transplantation.