Obesity and diabetes are commonly linked together. But, what causes that link? Is it coincidence or is there more of a causal relationship?
In this article, we’re going to discuss the link between obesity and diabetes.
Obesity and Diabetes
Before we get into how obesity and diabetes are linked, let’s first clarify what they both are.
Diabetes is a metabolic condition. There are two types of diabetes, type I and type II:
- Type I Diabetes: Occurs when the body doesn’t have enough insulin to regulate blood glucose levels.
- Type II Diabetes: Occurs when the insulin produced doesn’t effectively regulate blood glucose levels, or the body stops insulin production.
90% of diabetics are classed as type II. Only type II diabetes is linked to obesity and other modifiable lifestyle factors. Type I diabetes is strongly linked to genetics. Therefore, for this article, we will focus on the link between obesity and type II diabetes, and both are strongly linked to lifestyle factors.
Individuals are considered overweight if their BMI is between 25 and 29.9, and obese individuals have a BMI of 30 or more.
Prevalence of Obesity and Diabetes
62% of the English population is classified as overweight or obese. Overweight individuals are 3 times more likely to develop type II diabetes compared to somebody of a healthy weight. Furthermore, obese individuals risk is increased to 7 times more likely. Considering 62% of the English population is classified as overweight or obese, type II diabetes is a major health concern.
In 2013, it was proposed 7.4% of the adult population were type II diabetics. Due to the impact of obesity on type II diabetes, the rising prevalence of obesity will continue to increase the prevalence of type II diabetes. Predictions state by 2030 4.6 million or 9.5% of the English population will be type II diabetic, with one-third of this increase being due to obesity.
Risk Factors for Type II Diabetes
Overweight and obesity aren’t the only risk factors for type II diabetes. Other risk factors include inactivity, diet, age, genetics, ethnicity, and deprivation. The more risk factors, the higher risk of developing type II diabetes.
Type II diabetes and obesity are strongly related to diet and exercise. Typically, those who consume an unhealthy diet and are inactive have a greater risk of developing type II diabetes. Diets and activity levels are highly dependent on physical, social, environmental, economic, psychological, and cultural factors.
Type II diabetes risk also increases if you’re a smoker. Research shows regular smokers are 30-40% more likely to develop type II diabetes compared to non-smokers. The risk also increases as the number of cigarettes smoked per day increases.
As we age our risk of developing type II diabetes increases. Type II diabetes prevalence rates within different age groups are as follows:
- 16-34: 2%
- 35-54: 5.1%
- 55-74: 14.3%
- >75: 16.5%
Ethnicity and type II diabetes are strongly linked. All minority groups, except Irish, are at a higher risk of developing type II diabetes compared to the general population. Pakistani, Bangladeshi, black Caribbean, and Indian individuals are at particular risk of developing type II diabetes. Research also shows diabetes affects people of South Asian, African-Caribbean, Chinese, or black African ethnicity 10 years or more earlier than white Europeans.
Differences in ethnicity and type II diabetes risk are due to a combination of environmental and genetic factors. BMI thresholds are lower in black, Asian, and other ethnic minority groups to indicate when health interventions should occur. Thus, the weight of ethnic minority groups has a reduced range when health is considered normal.
Type 2 diabetes is 40% more common among people in the most deprived quintile (compared to the least deprived quartile) in England. Deprived populations are at higher risk of obesity, inactivity, consuming unhealthy diets, and smoking. Each of these factors links to the development of type II diabetes.
Link Between Obesity and Diabetes
Overweight and obesity remain the primary modifiable risk factor for type II diabetes. The higher our BMI, the higher our risk of developing type II diabetes. Those with severe obesity or who have been obese for a long period have an even greater risk of developing type II diabetes.
Those with a large waist circumference also have a greater chance of developing type II diabetes. Males with a waist circumference of 90-102cm have a high risk of developing type II diabetes, with the risk being classified as very high when their waist exceeds 102cm. For females, their type II diabetes risk is high when their waist circumference is between 80-88cm, with the risk being classified as very high when the waist exceeds 88cm.
Although there is no exact answer as to why obesity and type II diabetes are linked, there are some theories:
- Metabolism: Obesity may trigger the release of fatty acids, glycerol, hormones, pro-inflammatory cytokines, and other products from adipose tissue that cause changes in metabolism. These changes influence insulin resistance.
- Pro-inflammatory Chemicals: Obesity specifically around the midsection might lead to fat cells releasing pro-inflammatory chemicals. These chemicals can lead to insulin insensitivity by interfering with the insulin-responsive cells.
Diabetics are at a greater risk of developing other adverse health conditions such as blindness, limb loss, kidney dysfunction, depression, and cardiovascular disease, amongst other conditions.
- Cardiovascular Disease: The risk of developing cardiovascular disease doubles for type II diabetics.
- Vision Loss: Blindness, due to diabetic retinopathy, is the number one preventable vision loss of people in the UK.
- Limb Loss: Statistics show approximately 100 people per week have a limb amputated as a consequence of diabetes.
- Depression: Depression is 2x more prevalent in type II diabetics compared to those without the condition, with higher rates in women compared to men.
- Kidney Dysfunction: Type II diabetes relates to the development and progression of chronic kidney disease and end-stage renal disease.
Collectively in England and Wales, diabetes remains a major cause of mortality. In addition to adverse health consequences, type II diabetics can have a negative effect on relationships, work, income, health, wellbeing, and overall lifestyle. Finally, at the age of 50, the life expectancy of type II diabetics is six years lower than those without the condition.
Obesity significantly increases the risk of developing type II diabetes. Type II diabetes can lead to a lower life expectancy, blindness, limb loss, kidney dysfunction, depression, and cardiovascular disease.
Obesity remains the number one modifiable risk factor for type II diabetes. 90% of adults with type II are overweight or obese. There are multiple risk factors for type II diabetes, with some ethnic minority groups and deprived areas putting people at a particularly high risk of developing type II diabetes.
Obesity and type II diabetes remain major health challenges. Obesity and type II prevalence is on the rise and show no signs of slowing down. As a trainer, our focus remains on eating a healthy diet and exercising regularly to reduce the risk of obesity and thus type II diabetes. Different groups may be at a higher risk of developing type II diabetes due to their background and/or environment, thus we need to focus on controllable factors such as diet and exercise.
If you’d like to learn more about Diabetes and how exercise can support people living with this condition, then have a look at our short CPD training here.
Public Health England: Adult obesity and type II diabetes (https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/338934/Adult_obesity_and_type_2_diabetes_.pdf)