How is obesity linked to diabetes?

The UK has one of the highest rates of obesity in Europe with around one in every four adults and one in every five children aged 10–11 being classed as obese. Being obese can lead to many serious conditions that can be potentially life-threatening, including type 2 diabetes. 

What’s the difference between being obese and being overweight?

The phrases ‘overweight’ and ‘obese’ are both used to describe individuals who have more body fat than is considered healthy. However, those who are classed as obese will have more body fat than someone who is overweight, and will therefore be at greater risk of developing health issues.

How is obesity calculated and diagnosed?

One of the most common methods of checking if you’re a healthy weight is to calculate your body mass index (BMI). Your BMI will fall within one of the below ranges:

• 18.5 to 24.9 — healthy weight
• 25 to 29.9 — overweight
• 30 to 39.9 — obese
• 40 and above — severely obese

While BMI can give you an indication of whether you’re a healthy weight, it isn’t a definitive diagnosis of obesity as people with a lot of muscle and very little fat can also have a high BMI. 

Another important measure of whether you’re obese is therefore your waist measurement. Typically, a man with a waist size of 94cm or more and a woman with a waist of 80cm or more are likely to be obese. 

What are the health risks of obesity?

There are several health risks associated with obesity, which is why it’s important to take steps to lose excess weight. As well as physical changes that can affect your energy levels and put extra pressure on your joints, obesity can lead to life-threatening conditions, including:

• Coronary heart disease
• Different types of cancer
• Stroke
• Type 2 diabetes

What is diabetes?

Diabetes is a condition that causes your blood sugar levels to remain too high. This lifelong condition is caused either by an inability of your body to produce enough or any insulin or your cells not responding to the insulin produced. In either case, sugar in your blood (glucose) isn’t absorbed by your cells, which causes high blood sugar levels. 

There are two main types of diabetes:

• Type 1 diabetes — when your body’s immune system attacks and destroys the cells in your pancreas that produce insulin
• Type 2 diabetes — when your body’s cells don’t respond to insulin or in some cases, too little insulin is produced by your body

Type 1 diabetes often starts in childhood or during the teenage years, although it can also start in adulthood. Around one in 10 people in the UK are affected by type 1 diabetes, with genetics and certain viruses putting you at greater risk of developing it. 

Type 2 diabetes is more common in the UK, with around 90% of adults diagnosed with diabetes having type 2 diabetes. Once type 2 diabetes develops, as with type 1 diabetes, it will need to be managed for the rest of your life to avoid serious, long–term effects. 

How is obesity linked to type 2 diabetes?

Although the exact causes of diabetes are not fully understood, there are several factors known to increase your risk of developing it, including obesity. It’s estimated that obesity is the largest risk factor for type 2 diabetes, accounting for 80–85% of the risk. 

Carrying excess weight around your stomach also puts you at greater risk. Studies have suggested that abdominal fat can cause fat cells to release chemicals that increase inflammation, which is a common feature of diabetes. 

Increased inflammation can make your body’s cells less sensitive to insulin, leading to insulin resistance.

Obesity also causes changes in your metabolism, leading to fat molecules being released into your blood. This can also make your body’s cells less sensitive to insulin.

What are the symptoms of type 2 diabetes?

There are several common symptoms of diabetes and you should see your GP if you experience them. These include:

• Blurred vision
• Cuts that heal slowly
• Feeling very tired or very thirsty
• Itching around your penis or vagina
• Unintentional and unexplained weight loss and loss of muscle
• Urinating more often, especially at night

It’s important to get a diagnosis for type 2 diabetes as early as possible if you experience symptoms, as without treatment the condition will worsen over time.  

What is prediabetes?

A lot of people have blood sugar levels that are above the normal range but that aren’t high enough to be diagnosed as diabetes. This is called prediabetes.

If you’re diagnosed with prediabetes you should make lifestyle and diet changes to better control your blood sugar levels and reduce your chances of developing type 2 diabetes.

How is type 2 diabetes treated?

In most cases, medication is needed to control type 2 diabetes. In the first instance, the drug metformin is often prescribed to help control your blood sugar levels. You may have to take medication for the rest of your life, although the specific drug and dose may change over time.

It’s also important to make lifestyle changes that allow you to control your blood sugar levels, such as following a low-carbohydrate, low-sugar diet and increasing your activity levels.

Can losing weight affect diabetes?

Losing weight can help reduce your chances of developing type 2 diabetes if you’re overweight or obese. Research suggests that losing 5–7% of your body weight could cut down your chances of developing the condition by over 50%. 

Losing weight tends to decrease insulin resistance, which makes it much easier to control your blood sugar levels. In some cases, weight loss can lead to healthy blood sugar levels, such that you may no longer need to take medication. 

As well as helping you manage your diabetes or reduce your chances of developing type 2 diabetes, losing weight when you’re obese can lead to other physical and mental health benefits. These include:

• Better energy levels
• Improved mobility
• Improved self–esteem and confidence
• Lower cholesterol levels
• Reduced chances of other health conditions, including heart disease and kidney disease
• Reduced joint and back pain

To enjoy these benefits, try to follow a balanced, calorie-controlled diet and perform gentle exercise for 150–300 minutes each week. 

You may also benefit from psychological support from a professional to help change the way you think about food and to break unhealthy habits. 

If you’re struggling to lose weight or are concerned that you’re experiencing symptoms of type 2 diabetes, make an appointment with your GP. They can test your blood sugar levels to assess your risk of developing diabetes and offer advice and support to help you lose weight.