Health risks of adult obesity
There is now good evidence to show that adult obesity is associated with a wide range of health problems, these are summarised below.
- Raised body weight puts strain on the body's joints, especially the knees, increasing the risk of osteoarthritis (degeneration of cartilage and underlying bone within a joint).
- There is also an increased risk of low back pain.
- Raised BMI increases the risk of hypertension (high blood pressure), which is itself a risk factor for coronary heart disease and stroke and can contribute to other conditions such as renal failure.
- The risk of coronary heart disease (including heart attacks and heart failure) and stroke are both substantially increased.
- Risks of deep vein thrombosis and pulmonary embolism are also increased.
Metabolic and endocrine systems
- The risk of Type 2 diabetes is substantially raised: it has been estimated that excess body fat underlies almost two-thirds of cases of diabetes in men and three quarters of cases in women. Diabetes currently affects nearly 200 million people worldwide and International Diabeted Federation predict that this will increase to over 330 million by 2025, with a massive burden in developing countries. Worldwide, the number of people with diabetes has tripled since 1985.
- There is a greater risk of dyslipidemia (for example, high total cholesterol or high levels of triglycerides), which also contributes to the risk of circulatory disease by speeding up atherosclerosis (fatty changes to the linings of the arteries).
- Metabolic syndrome is a combination of disorders including high blood glucose, high blood pressure and high cholesterol and triglyderide levels. It is more common in obese individuals and is associated with significant risks of coronary heart disease and Type 2 diabetes.
- The risk of several cancers is higher in obese people, including endometrial, breast and colon cancers.
Reproductive and urological problems
- Obesity is associated with greater risk of stress incontinence in women.
- Obese women are at greater risk of menstrual abnormalities, polycystic ovarian syndrome and infertility.
- Obese men are at higher risk of erectile dysfunction.
- Maternal obesity is associated with health risks for both the mother and the child during and after pregnancy. Click here for more information on maternal obesity
- Overweight and obese people are at increased risk of sleep apnoea (interruptions to breathing while asleep) and other respiratory problems such as asthma.
Non-alcoholic fatty liver disease
- The term ‘non-alcoholic fatty liver disease’ (NAFLD) refers to a range of conditions resulting from the accumulation of fat in cells inside the liver. It is one of the commonest forms of liver disease in the UK. If left untreated, it may progress to severe forms such as non-alcoholic steatohepatitis (NASH), fibrosis and cirrhosis. It has also been linked to liver cancer.
- Obesity is an important risk factor for the condition: over 66% of overweight people, and over 90% of obese individuals are at risk of NAFLD [Argo CK, Caldwell SH. Epidemiology and natural history of non-alcoholic steatohepatitis. Clin Liver Dis 2009; 13: 511-531]. As levels of obesity have risen, so has the prevalence of NAFLD.
- There is a lack of high quality data related to the prevalence of NAFLD in the UK. This is due to a number of factors including variations in diagnostic criteria, the invasive nature of diagnosis, and the lack of symptoms in people with mild forms of the condition.
- Approaches to tackling the condition focus on weight reduction through a combination of diet and physical activity, but there is no specific evidence-based treatment for NAFLD.
- Scientific understanding of the condition is limited, and there is a lack of high quality data on it. The impact of rising obesity levels on the prevalence and severity of NAFLD is not known, nor are the natural history or optimal management of the condition. There is a lack of scientific consensus on just how significant a threat to health NAFLD presents. In order to explore these issues in more detail we held an initial expert workshop in October 2013, and are continuing to develop this work in PHE and with external partners.
- Improvements in outcomes from NAFLD will require better data collection through primary and secondary care, death certification, and transplant registers, as well as research into the causes and treatment of the condition.
Obesity is associated with:
- Increased risk of gastro-oesophageal reflux
- Increased risk of gall stones
Psychological and social problems
- Overweight and obese people may suffer from stress, low self-esteem, social disadvantage, depression and reduced libido.
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